Feeler thread about 8.4V 2A Li-Ion charger for 2SxP battery packs- Mtbr.com
Results 1 to 136 of 136
  1. #1
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810

    Feeler thread about 8.4V 2A Li-Ion charger for 2SxP battery packs

    I've got the feeling there is a lack of simple chargers with higher currents in order to charge our battery packs in decent time. Mostly we can get the chargers declared 1000mA which is nowere near the truth and charging high capacity battey packs takes forever. Me personaly has also Magicshine charger with 1.8A and I'm mostly fine. Still think it's more on the low side in reality.

    I've started to find out China manufacturers being able to make good charger with some security fetures. Then if they decide so, some reseller like Gearbest would take over to distrubute them.

    Here in this thread I want to discover how much demand there would be for such a charger. We should not discuss about the features as they are mostly defined and I don't see the reason to change them significantly. No intensions to get another hobby charger.

    So here are the basic features:

    Wall plug 8.4V Li-Ion charger with:

    • two phase CC/CV charging algorithm
    • AC plug: US, EU, UK (AU? if does not raise the costs )
    • DC output: connector 5.5x2.1mm
    • true 2.0A DC output current
    • regulated output voltage 8.40V
    • red/green status led (switch from red to green at 1/10 ie. 200mA)

    Safety:
    • Over Voltage protection
    • Short Circuit protection
    • Polarity error protection
    • Over power protection
    • 20mA efectively termination current (ie. completly stops charging)

    Of course there are also other fetures like operating templ, humidty, some electrical stuff we normaly don't think off, etc..

    I'm at very beginning contacting one manufacturer, so there is a lot of work to do.....

    Now the stage is yours.

  2. #2
    mtbr member
    Reputation:
    Join Date
    Nov 2012
    Posts
    1,043
    I'm not sure I really know the difference between a hobby charger and advanced single cell charger.

    On your list of things which are not already done by the Magishine charger?

    I was doing some research on advanced AA/AAA nimh chargers and one of features touted by the ability to select the charging rate. The reviewer mentioned that he prefers the lower charging rate as it avoids heat build up which degrades the lifespan of the batteries. Is this not an issue with lithium bike light batteries? What's the maximum safe charge current of the lithium batteries?

    It would like a pack charger that has a readout that shows me the charging progress as well as the total charge applied to the battery. It was also be nice if the charger could be perform an entire discharge/charge cycle and calculate the total capacity of the battery, as well as detecting a bad pack. Is that the kind of thing you had in mind?

  3. #3
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    varider, no I have in mind simple charger very similar to those you are getting within bilke light sets. The difference would be only higher current/faster charge and most important known/tested safety features. The size and the weight of the charger would be bigger up to 190gr.
    I'm not shure how much do you know about Li-Ion batteries. I recomend reading Charging Lithium-Ion Batteries ? Battery University - charging and other chapters too.

    About charging rate. Recomended for Li-Ion is 0.5C which in terms of 2200mAh cell means 1.1A. This is the lowest capacity we are using nowadays. So if you are using 3400mAh cells 0.5C would be 1.7A. Now if we apply this to the xS2P batery pack the 2.2A - 3.4A is recomended for 2 cells in paralell. With 2A we are still below the recomended charging current. 2A applies only to CC phase.

    Designing charger with readouts, charging, dischargin capacity, etc. is totaly useless. It will raise price significantly and for that price you would get hobby charger already doing all that and more. I don't say it would not be handy, it is just the price would be to high since ith as to be developed from the scratch.

  4. #4
    mtbr member
    Reputation:
    Join Date
    Aug 2013
    Posts
    829
    If I understand correctly, the charger you're describing is essentially exact copy of already existing MagicShine standard 1.8A and 2.5A chargers. Are you sure your variant will be any better?

  5. #5
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Well, probably yes, but should be cheaper with well known safety features. I'm not aware of 2.5A version. Can you point it out?

  6. #6
    mtbr member
    Reputation:
    Join Date
    Dec 2014
    Posts
    149
    Does the magic shine 1,8A charger have an advanced charging algorithm?

  7. #7
    mtbr member
    Reputation: Ofroad'bent's Avatar
    Join Date
    Jul 2010
    Posts
    1,434

  8. #8
    mtbr member
    Reputation:
    Join Date
    Aug 2011
    Posts
    747
    Quote Originally Posted by varider View Post
    It would like a pack charger that has a readout that shows me the charging progress as well as the total charge applied to the battery. It was also be nice if the charger could be perform an entire discharge/charge cycle and calculate the total capacity of the battery, as well as detecting a bad pack. Is that the kind of thing you had in mind?
    Well as you probaly know the XTAR VC2 does mostly all that except it doesn't perform the discharge cycle, you have to run out your batteries yourself. Maybe kinda difficult if your setups all have high over-discharge thresholds?.

  9. #9
    Just Ride !
    Reputation: C.M.S's Avatar
    Join Date
    Aug 2009
    Posts
    842
    Quote Originally Posted by ledoman View Post
    Well, probably yes, but should be cheaper with well known safety features. I'm not aware of 2.5A version. Can you point it out?
    It's for the 880 that uses a different plug , but I assume it could be easily modded with a standard connector ??
    Action LED Lights - Brilliant lighting for all your biking & outdoor sporting activities.

    But yes I'm all in for a simple charger like the 880 one with the standard connector .
    Hit the trails with your bike and get freaky. :cornut:

  10. #10
    mtbr member
    Reputation:
    Join Date
    Aug 2013
    Posts
    829
    Quote Originally Posted by ledoman View Post
    Well, probably yes, but should be cheaper with well known safety features. I'm not aware of 2.5A version. Can you point it out?
    Sure:
    MJ-6072 2.5A Battery Charger | Magicshine USA

  11. #11
    mtbr member
    Reputation:
    Join Date
    Aug 2013
    Posts
    829
    Quote Originally Posted by Appel View Post
    Does the magic shine 1,8A charger have an advanced charging algorithm?
    What do you mean?

  12. #12
    mtbr member
    Reputation:
    Join Date
    Aug 2013
    Posts
    829
    Quote Originally Posted by ledoman View Post
    • AC plug: US, EU, UK (AU? if does not raise the costs )
    IMHO, different versions of charger for regional power outlet standards is a bad thing, as well as using adapters (the're inconvenient & ugly looking).

    For me, ideal design is a replaceable power cord, as in modern MagicShine chargers: you can use one suitable for your location.

  13. #13
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    OK, I see. I thought the 1.8A is the highest.

    Archie, I can't design it. This will probably raise the price to much. I know it would be better, but the manufacturer has to see much $$$$ to design the whole new case and change production. Still I can ask.

  14. #14
    mtbr member
    Reputation:
    Join Date
    Aug 2011
    Posts
    747
    Quote Originally Posted by C.M.S View Post
    It's for the 880 that uses a different plug , but I assume it could be easily modded with a standard connector ??
    Action LED Lights - Brilliant lighting for all your biking & outdoor sporting activities.

    But yes I'm all in for a simple charger like the 880 one with the standard connector .
    Thing still is, the 2.5A charger for the MJ-880 is specifically designed for 6-cell packs. In MagicShine's own description, it should NOT be used to "fast charge" 2 or 4 cell battery packs. Guess that's why the different, rectangular connector — so might not be the best idea trying to mod it? Too bad.

  15. #15
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Andy, have you read this Charging Lithium-Ion Batteries ? Battery University ? Copied from that source:
    "The charge rate of a typical consumer Li-ion battery is between 0.5 and 1C in Stage 1, and the charge time is about three hours. Manufacturers recommend charging the 18650 cell at 0.8C or less."

    Tipical good brand cell is 2200mAh or more and 0.5C for it is 1.1A. Two cells in paralell is then safe to charge at 2.2A It can be chaged up to 1C so 4.4A or even more for higher capacity ones. Charging at higher currents would shorten lifetime and decrease capacity over the time. With 2A we are below tipical 0.5C

    Magicshine is using 2200mAh BAK cells so 2.5A should be still just fine to charge 2S2P packs, but not the 2S1P.

  16. #16
    mtbr member
    Reputation:
    Join Date
    Nov 2012
    Posts
    1,043
    Maybe you could bump up the current to the maximum safe level for a 6-cell pack. How about a simple switch to select the current.

  17. #17
    mtbr member
    Reputation:
    Join Date
    May 2011
    Posts
    324
    It seems to me that you want to be able to charge at different voltages 8.4v for the pack & 4.2 v for the individual cells, and at different currents depending on the quality and number of parallel cells.

    Maybe I am too skeptical, but to me it seems a hobby charger remains the better solution.

  18. #18
    mtbr member
    Reputation:
    Join Date
    Aug 2011
    Posts
    747
    Quote Originally Posted by ledoman View Post
    Andy, have you read this Charging Lithium-Ion Batteries ? Battery University ? Copied from that source:
    "The charge rate of a typical consumer Li-ion battery is between 0.5 and 1C in Stage 1, and the charge time is about three hours. Manufacturers recommend charging the 18650 cell at 0.8C or less."
    Thanks, that article was very clear!

    BTW ledoman did you read this the other day?

    Boffins say they've got Lithium batteries the wrong way around ? The Register
    Last edited by andychrist; 01-11-2015 at 04:41 AM.

  19. #19
    mtbr member
    Reputation:
    Join Date
    Apr 2006
    Posts
    23
    Quote Originally Posted by ledoman View Post
    Charging at higher currents would shorten lifetime and decrease capacity over the time.
    Hey!

    To be extra safe with capacity preservation I would go down to C/5, one fifth of 1 C, charge rate, that's where the capacity fade seems to level out if this NASA test paper page 11 is anything to go by.

    Smoke free charges!


    JK

  20. #20
    mtbr member
    Reputation: Ofroad'bent's Avatar
    Join Date
    Jul 2010
    Posts
    1,434
    Now I'm confused -What would the recommended amps be for charging 1S2P? (4.2v) I am assuming 2A is plenty safe.

    How about 2S1P? (8.4v) Is 2A safe for that, or too high, even with Pano cells? If so, A 2.5A charger would be too much.

    BTW, You may want to make your charger safe for 2S1P at least.

    Quote Originally Posted by ledoman View Post
    Andy, have you read this Charging Lithium-Ion Batteries ? Battery University ? Copied from that source:
    "The charge rate of a typical consumer Li-ion battery is between 0.5 and 1C in Stage 1, and the charge time is about three hours. Manufacturers recommend charging the 18650 cell at 0.8C or less."

    Tipical good brand cell is 2200mAh or more and 0.5C for it is 1.1A. Two cells in paralell is then safe to charge at 2.2A It can be chaged up to 1C so 4.4A or even more for higher capacity ones. Charging at higher currents would shorten lifetime and decrease capacity over the time. With 2A we are below tipical 0.5C

    Magicshine is using 2200mAh BAK cells so 2.5A should be still just fine to charge 2S2P packs, but not the 2S1P.

  21. #21
    mtbr member
    Reputation:
    Join Date
    Apr 2006
    Posts
    23

    Charging Currents

    Hi!

    Horses for courses. Slower charging is better for the battery health, but it does take its time.

    Quote Originally Posted by Ofroad'bent View Post
    What would the recommended amps be for charging 1S2P? (4.2v) I am assuming 2A is plenty safe.
    A charging current of 2A with two 2000 mAh cells in parallel equals to a 0.5C charge rate and is widely considered safe. One needs to pay attention to the voltage though.

    Quote Originally Posted by Ofroad'bent View Post
    How about 2S1P? (8.4v) Is 2A safe for that, or too high, even with Pano cells? If so, A 2.5A charger would be too much.
    A Panasonic NCR18650B often sold as a 3400 mAh cell is specified with a 1625mA charging current, or a 0.5C charge rate if you like, by the manufacturer. A Panasonic NCR18650 with a typical capacity of 2900 mAh is specified with a 1925 mA charging current, or a 0.7C charging rate, by the manufacturer, but was charged with a 2.9 A current, or a 1C charge rate, in the mentioned NASA test with no issues other than a steady decline in capacity.

    Quote Originally Posted by Ofroad'bent View Post
    You may want to make your charger safe for 2S1P at least.
    A high current charger is not best suited to low capacity packs and should not be used to charge one. Luckily there is an abundance of slow low current chargers available, as every light set comes with one, to use with low capacity packs and the goal here is to get a quick one for the big ones.

    Bright rides!


    JK

  22. #22
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Quote Originally Posted by Ofroad'bent View Post
    Now I'm confused -What would the recommended amps be for charging 1S2P? (4.2v) I am assuming 2A is plenty safe.

    How about 2S1P? (8.4v) Is 2A safe for that, or too high, even with Pano cells? If so, A 2.5A charger would be too much.
    You can simply calculate it. Recomended is 0.5-1.0C (C stands for Capacity). Take the pack capacity and divide it by 2 (0.5) and you get the bottom recommended current for that pack.

    Quote Originally Posted by Ofroad'bent View Post
    BTW, You may want to make your charger safe for 2S1P at least.
    For those you already have plenty chargers out there charging at 1A (1000mAh) or less. If we take 2S1P into account there is no point to make any effort for faster 2A charger.

  23. #23
    mtbr member
    Reputation: Ofroad'bent's Avatar
    Join Date
    Jul 2010
    Posts
    1,434
    Quote Originally Posted by ledoman View Post
    You can simply calculate it. Recomended is 0.5-1.0C (C stands for Capacity). Take the pack capacity and divide it by 2 (0.5) and you get the bottom recommended current for that pack.



    For those you already have plenty chargers out there charging at 1A (1000mAh) or less. If we take 2S1P into account there is no point to make any effort for faster 2A charger.
    To be clear here, you are recommending 1.0A-1.6A for a 1S2P ( 2-cell 8.4v pack) depending on the type of cells as a safe charge level, and 2A-2.5A won't destroy them but may shorten their life?

  24. #24
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Ofroad, charging current has nothing to do with how many cells are in series. Voltage depends on that.
    For the charging current there is important only capacity of the pack (not cells on it's own - theoreticaly they don't need to be and are not the same capacity). Shureley capacity depends on the number of cells in parallel and their capacity. When we doing math we always assume cells has equal capacity (which is not true exactly)

    1. If we take Magicshine BAK cells:
    Nr. cells in parallel Cap C 0.5C 1C
    1 2200 2.2 1.1 2.2
    2 4400 4.4 2.2 4.4
    3 6600 6.6 3.3 6.6

    2. If we take Panasonic 3400:
    Nr. cells in parallel Cap C 0.5C 1C
    1 3400 3.4 1.7 3.4
    2 6800 6.8 3.4 6.8
    3 10200 10.2 5.1 10.2

    Quote Originally Posted by Ofroad'bent View Post
    To be clear here, you are recommending 1.0A-1.6A for a 1S2P ( 2-cell 8.4v pack) depending on the type of cells as a safe charge level, and 2A-2.5A won't destroy them but may shorten their life?
    2-cell 8.4v pack is not 1S2P, but 2S1P, you are doing wrong calculaton.

    To apply values from the tables on two cell 8.4V pack (2S1P):
    1. BAK cells: 0.5C = 1.1A and 1C = 2.2A
    2. Pany cells: 0.5C = 1.7A and 1C = 3.4A

    2A charger is complety safe for BAK and Pany cells It just not recomended for BAK and completly good for Panys with about 0.6C.

    Generaly if you are within 0.5 and 1C limits you are on safe side, it is just lifetime would be shortened with higher. Take anology with engine. If you run it at it's upper limits it will worn out sooner. In fact with quality cells like Panasonic you can even go bit over 1C and you'll still be safe.

  25. #25
    mtbr member
    Reputation: Ofroad'bent's Avatar
    Join Date
    Jul 2010
    Posts
    1,434
    Quote Originally Posted by ledoman View Post
    Ofroad, charging current has nothing to do with how many cells are in series. Voltage depends on that.
    For the charging current there is important only capacity of the pack (not cells on it's own - theoreticaly they don't need to be and are not the same capacity). Shureley capacity depends on the number of cells in parallel and their capacity. When we doing math we always assume cells has equal capacity (which is not true exactly)

    2-cell 8.4v pack is not 1S2P, but 2S1P, you are doing wrong calculaton.

    To apply values from the tables on two cell 8.4V pack (2S1P):
    1. BAK cells: 0.5C = 1.1A and 1C = 2.2A
    2. Pany cells: 0.5C = 1.7A and 1C = 3.4A

    2A charger is complety safe for BAK and Pany cells It just not recomended for BAK and completly good for Panys with about 0.6C.

    Generaly if you are within 0.5 and 1C limits you are on safe side, it is just lifetime would be shortened with higher. Take anology with engine. If you run it at it's upper limits it will worn out sooner. In fact with quality cells like Panasonic you can even go bit over 1C and you'll still be safe.
    Thanks, I meant 2-cell 2S1P. It's perfectly clear now, +rep given to you for lots of good info!

  26. #26
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Thanks for +rep. I'm actualy thinking even 2.5A would be good for newer cell capacities starting at 2600mAh per cell. Sooner or later we are all going to have packs with higher capacities.

    Tomorow I'll be getting two latest Magicshine chargers (1.8 and 2.5A) to test at what current they actualy charges. Will do only brief tests since I have to return them back to the local seller.

  27. #27
    mtbr member
    Reputation:
    Join Date
    Sep 2012
    Posts
    178
    Quote Originally Posted by andychrist View Post
    Well as you probaly know the XTAR VC2 does mostly all that except it doesn't perform the discharge cycle, you have to run out your batteries yourself.
    I think you probably meant the VP2, not the VC2. With the VP2, unplugged from the wall, with a load plugged into the USB, it acts as a battery bank (ie you drain the batteries). I believe the screen monitors the two cells while it is draining them.

  28. #28
    mtbr member
    Reputation:
    Join Date
    Aug 2011
    Posts
    747
    Quote Originally Posted by Ian_C View Post
    I think you probably meant the VP2, not the VC2. With the VP2, unplugged from the wall, with a load plugged into the USB, it acts as a battery bank (ie you drain the batteries). I believe the screen monitors the two cells while it is draining them.
    No, the VC2 is a separate model only available through XTAR itself. It has a tachometer style display and if you drain the batteries before charging, it will tell you their real capacity in mAh when full. AFAIK the VP2 can't do that, it shows voltage but not mAh.

    Feeler thread about 8.4V 2A Li-Ion charger for 2SxP battery packs-image.jpg

    And it's only $19.90!

  29. #29
    mtbr member
    Reputation:
    Join Date
    Aug 2013
    Posts
    829
    Quote Originally Posted by andychrist View Post
    and if you drain the batteries before charging, it will tell you their real capacity in mAh when full.
    Their advertizing is a bit too optimistic...

  30. #30
    mtbr member
    Reputation:
    Join Date
    Sep 2012
    Posts
    178
    I'd read it's specs a month or so ago, but that detail didn't stick. The glowing reviews and flexibility of the VC2 rated it as a better charger.

    Didn't we have a discount code for the VC2 lowering its price to $22?

  31. #31
    mtbr member
    Reputation: garrybunk's Avatar
    Join Date
    Feb 2014
    Posts
    1,745
    Count me in on a 2.0 to 2.5A standard wall plug style charger. I do wonder if it's reasonable to ask for a current selection switch to switch between 1A and 2A (or 1A & 2.5A). Could be icing on the cake, but not necessary.

    -Garry

  32. #32
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Garry, this might raise the price. I know it would be nice, but yet there are plenty 1A chargers out there for cheap. And there is possibilty one to forget to switch from 2.5A to 1A on low capacity pack. This charger will be definitively bigger so it would look different and implicitly tells you to use it with high capacity pack. Well, I think so

  33. #33
    mtbr member
    Reputation: mtrain's Avatar
    Join Date
    May 2008
    Posts
    150
    Quote Originally Posted by Ofroad'bent View Post
    Hunk-lee's battery are rated highly, so i wonder about this charger from him? Too bad I just received the batteries I ordered from him. Don't feel like waiting another 3 1/2 weeks for a charger....

  34. #34
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Something like that would be perfect (if we know all safety features build in), but probably to expensive to sell in quanties.

  35. #35
    Chunky Monkey
    Reputation: circusubet's Avatar
    Join Date
    Aug 2006
    Posts
    413
    Quote Originally Posted by ledoman View Post
    Something like that would be perfect (if we know all safety features build in), but probably to expensive to sell in quanties.
    Led, let me first say thanks for everything you and the other well educated light swamis post. You, and the others, help myself and others more than you know. Enough unabashed sucking up......You have hit need on the head! There are several of us that as Cat said, " So many just want a plug and play, light, battery and charger". I think it was Cat. However because of threads like this I learn whether or not I want to.....I actually cracked my first light a few days ago. I am also going to use the GB box to start doing my own cells.

    I would be in for this kind of charger.

    Thx
    John
    Last edited by circusubet; 01-13-2015 at 10:20 PM. Reason: Add sentence.
    Lurkers Unite! Never mind....

  36. #36
    mtbr member
    Reputation:
    Join Date
    Mar 2015
    Posts
    3
    Did you get any further with this?
    I've found Master instruments do a 3Amp Charger but they are in Australia:
    Master Instruments - 100-240VAC Input LiIon 2 Cell 8.4V Charger Output 3A + 2.1mm DC Plug
    I'm rather looking for a 4A Charger myself.
    I have a few 2S4P 8Ah packs, and am building a 2S3P pack with Panasonic 3400s, that will be 10Ah.
    I've tried the Magicshine 2.5A charger, but that burnt out internally for some reason.

  37. #37
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Currently I'm working on getting a sample from one of the manufacturers. It is going to be 2A charger. I uderstand 3A or even 4A would be nice, but we need to cover the widest range of capacities and still be on the safe side at the same time ie. charging below 0.5C. I'm shure good quality cells would easily stand up to 1C, but again we have to cover some users who don't care much about technology behind. To high charging current would put them into risk. We can go one step further in the next round with 3-4A charger. This is my humble opinion.

  38. #38
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Just want to let you know the 3 samples are on the way to me and HKJ from BLF forum. As soon we do at least some basic testing I'm going to publish preview.

    It would be nice if you would express your interest on them. Of course if they are good enough quality which we must prove first.

  39. #39
    mtbr member
    Reputation:
    Join Date
    Aug 2011
    Posts
    747
    Do you have any estimate how much they'll retail, ledoman?

    Thanks!

  40. #40
    mtbr member
    Reputation:
    Join Date
    Oct 2009
    Posts
    650
    Would it be worth seeing if the charger that nitefighter provides with the BT40 meets these criteria? I know its labeled as 2 amps and seems robust in design. Perhaps they would sell separately if so?

  41. #41
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    @andychrist, I'm not shure about the prices yet, since this is the reseler decision. I can only guessing and hoping it would be less than $10, but the minumum order from manufacturer is 200 pieces per batch/model. And currently we have three different models to test and three different prices. I'll publish any data as soon I'll get some.

    @manbeer, can you get some contact person to talk to and links to the BT40 charger? Will take a look.

  42. #42
    mtbr member
    Reputation: garrybunk's Avatar
    Join Date
    Feb 2014
    Posts
    1,745
    Glad to hear this is moving along. I'm interested, but likely only for one, maybe two if price is really good.

    -Garry

  43. #43
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Will see about the quality. HKJ will do deep electrical analysis. I can also say the most atractive model has 4 interchangable wall plugs. This is most likely the one we would prefer since with the other two models the 200pcs/model barier is probably for each plug version. Will have to check that, though.

  44. #44
    mtbr member
    Reputation:
    Join Date
    Oct 2009
    Posts
    650
    I believe one of the company's owners or salespeople is on this forum under the user name "Waldens" and i think his name is andy wong. They seem to be responsive to working with the public when contacted through alibaba/aliexpress and sell just the lightheads and just the batteries so they may be a viable option

    The charger is listed as 2 amps and i don't really know how to confirm this BUT i just ordered one of these which will be arriving monday so am i correct in assuming i can drain a battery and use this in line once i am charging it? also got setup to wire it with 5.5x2.1 plugs for testing. Worst case i can just time the charge vs my hobby charger at 2amps and compare

    Here is a link to the page for the manufaturer but beware, it loads incredibly slow!

    NITEFIGHTER

    not sure if they mention anything about the charger but it seems to use the same case as my old magicshine chargers from geoman.

  45. #45
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Thanks, but I couldn't find charger anywhere on that site. Would you mind taking the pictures of yours includig specifications on the label?

    Comparing time with hobby charger won't be to much accurate. You would need to read the current through the whole cycle and see what the current curve looks like. Hobby chargers should strictly follow CC/CV type of charging while some cheapo chargers don't or at least not very good.

  46. #46
    mtbr member
    Reputation:
    Join Date
    Oct 2009
    Posts
    650
    Yes, I will be back at store tomorrow (left charger there) and will take care of it asap

  47. #47
    mtbr member
    Reputation:
    Join Date
    Aug 2011
    Posts
    747
    NiteFighter charger same as bottom photo on hunk_lee's ebay site for his, posted earlier in this thread.

    Feeler thread about 8.4V 2A Li-Ion charger for 2SxP battery packs-image.jpgFeeler thread about 8.4V 2A Li-Ion charger for 2SxP battery packs-image.jpg

    Think the currently shipping 1.8A MagicShine is a bit heftier though.

    Funny but when the MagicShine charger goes green, the [built-in] meter on my MJ-828 4400mAh battery pack reads 8.3V. Plugging it into the NiteFighter after that, reads 8.5V and continues to charge for about a minute, with LED on unit pulsing red before going all green. Final reading oscillates between 8.5 and 8.4, stays 8.4 when disconnected from charger.

  48. #48
    mtbr member
    Reputation: garrybunk's Avatar
    Join Date
    Feb 2014
    Posts
    1,745
    Hmm. . . According to the charger label you can only open it up in a public place.

    -Garry

  49. #49
    mtbr member
    Reputation:
    Join Date
    Oct 2009
    Posts
    650
    Quote Originally Posted by garrybunk View Post
    Hmm. . . According to the charger label you can only open it up in a public place.

    -Garry
    damn, that'll go great with my mj 880 clone who's "cute shape was design to replicate the head of an owl for optimum heat release" or something along those lines

  50. #50
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Thanks andy. From photos it can be seen it might deliver 2000mA - size wise at least.

    Well MJ-828 battery pack shows only tenth of volt not hudreds so there is +/- 0.1V = 0.2V difference (0.1999 to be exact) which is a lot. I would take it's display only as a good enough orientation what's going on for general use, but it is not to be used to tell you how good the chager is.

    There are many, many cheapo chargers stating 1000mA while in reality can deliver only about 600mA. This is not anything bad per se, it is just it will take a lot of time to charge the pack. I got few in may hand which were bad or did not follow CC/CV way of charging. One of them was 12V power adapter, not Li-Ion charger

    As told before we must see what the charging current curve is in reality and take voltage drop and connector resistance into account. Final voltage is also important thing. Another is when signaling led turns from red to green, etc....

    I hope we will get nice beaviour samples with current and CC/CV as described. I can expect to get them on monday or tuesday. We are going to check them electricaly in details including safety issues and compliance to the CE standard. Of course this will take quite some time. The general behaviour would be known by the end of the next week.

  51. #51
    mtbr member
    Reputation:
    Join Date
    Aug 2011
    Posts
    747
    ledoman, what is the "continuous" power consumption in wattage of these chargers? Am assuming it varies with charging stage, but would be interesting to know what the maximum rate is. Say for the Nitefighter, Output is 8.4V/2000mA which would be the equivalent of 16.8W; if we knew the efficiency maybe we could calculate at least approximately how many watts it would burn when running at its highest level. Thanks.

  52. #52
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Andy, during deep electrical test this would also be examined and I think HKJ will plot the output current curve. So you would easily see how it behaves. Efficiency is declared by manufacturer and it's >80%. Peak power consuption would then be 8.5V*2A/0.8 = 21.25W. We will see if this is true.
    The other two models are declared 2.5-3A. If it is not that high, I hope it will be at least 2A. Please give us some time to receive samples. I hope there will be no problems with customs. EU is much more strict than US.

    Of course all questions are welcome then.

  53. #53
    mtbr member
    Reputation:
    Join Date
    Aug 2011
    Posts
    747
    Deleted Duplicate Post
    Last edited by andychrist; 04-12-2015 at 10:33 AM. Reason: Duplicate

  54. #54
    mtbr member
    Reputation:
    Join Date
    Aug 2011
    Posts
    747
    Thanks ledoman. Sorry I didn't mean to jump the gun but was curious, as the guys in the bike shop brought up the question when they saw all the lamps and battery packs decorating my bike. 80% efficiency sounds really good for that kind of device!

  55. #55
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Well you know, it's Chinese manufacturer so we would know when we'll measure something. Don't know if we can check eficiency, but I can ask HKJ if he is able to do it.

  56. #56
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Just short information. Today I've got three Li-Ion charger samples made by same manufacturer:
    1. 2A, EU plug
    2. 3A, EU plug
    3. 3A, 4 interchangable plugs (US, EU, UK, AU)

    So far tested output voltage of 2. and it is 8.49V which is about OK. Just didn't have time to do anything more. Will add some preview later.....

  57. #57
    mtbr member
    Reputation: garrybunk's Avatar
    Join Date
    Feb 2014
    Posts
    1,745
    I'm sure you will already be doing this, but can you link HKJ's review here once it's posted? Thanks!

    -Garry

  58. #58
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Yes of course. I don't know how fast he would be able to test them. He is quite busy with all sort of testing. He has prommised me to do it as fast as he can, but he has still to do other stuff. I haven't hear from him if he has already got the samples. This is somewhat new to him and need to prepare correct setup in order to plot all the data.

  59. #59
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Quick preview pictures:

    1. TS-1084S - 2A EU plug, 22AWG wire



    2. TS-1012C - 3A EU plug, 18AWG wire





    3. TS-2012H - 3A with 4 intechangable plugs, 18AWG wire



    Last edited by ledoman; 04-16-2015 at 12:40 AM.

  60. #60
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Here we go. First testing of efficiency as per request of Andy.
    Test were done by HKJ. He will do all deep electrical testing and publish full reviews on his web site when finish. I'll publish some intermediate results here.







    Output voltage with no load, HKJs and mine samples:

    TS-1084S Unloaded voltage 8.67V and 8.59V
    TS-1012C Unloaded voltage is 8.48V and 8.49V
    TS-2012H Unloaded voltage 8.47V and 8.43V

    Talked to the manufacturer about TS-1084S model as it has to high voltage and they can reduce it in final products. Of course we have to do a lot more testing before decide anything.

  61. #61
    mtbr member
    Reputation:
    Join Date
    Aug 2011
    Posts
    747
    Thanks ledoman & HKJ!

    Glad the TS-2012H will support a NA plug.

    Will you guys also be plotting V over time?

    And, might the chargers' LEDs indicate the point somewhere between 8.25 and 8.3V when the current starts to drop off, maybe by flickering/flashing? (Not a request, just wondering if that was already a design feature. Trickle charge indication used to be pretty common but now I can't even remember where last I saw it.)

  62. #62
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Andy, yes of course this was just first step in a HKJs standard tests. Voltage vs. current plot is essential, but it takes quite some time. Depends on battery pack capacity this test would take many hours. I'm not shure if HKJ plans to do it with different battery packs, but shure he will do it against packs with good quality cells.

    The chargers indicate led is yet to be seen when it turns from red to green. It is hard to watch the charger all the time. I only know it turns green at some point and continues charging with descending current curve. We will of course try to catch that moment, but it may vary with some variance between each charger dependable on the variance of internal elements.

  63. #63
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Here is the official test of the first charger:

    Review of Charger TS-1084S 2S 2A LiIon

    It is not favorable unless manufacturer changes the output voltage. This output voltage issue was expected after I've tested output voltages of all three.
    I might manage to get corrected version to test, but it will take some time.
    Will see how it goes with other two.

  64. #64
    mtbr member
    Reputation: garrybunk's Avatar
    Join Date
    Feb 2014
    Posts
    1,745
    Glad to see a thorough review. Shame on the first one; let's see how the other two do. (No charge termination - Yikes!)

    -Garry

  65. #65
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Garry no, the charge termination is not a problem as long as current decreases towards 0. It is output voltage if to high, cells get charged to much. There is some allowed variance and the cells can be charged safely to 4.25V, they only get worn out sooner. Since we use them relatively seldom in compare to laptop packs, worning them out is not big issue. On the other side, this charger would be good for 4.35V cells.
    I know the reason why they made it so high, but they got it wrong. They used 22AWG wire and calculated voltage drop at full current, but forgot the current at the end of CV stage is small and so is the voltage drop.

    Also I have promises from the manufacturer they will lower the voltage in the final product of all three below 8.45V if we choose to buy any. Right now I have discussion to make new 2A sample for testing purposes.

    The other two has lower voltage output and I suspect they would be good enough as they are.
    Let wait few more days to HKJ publish the test results, then we can discuss which model would be most desirable and we can make group buy or similar.

  66. #66
    RAKC
    Reputation: tigris99's Avatar
    Join Date
    Aug 2012
    Posts
    7,146
    I am curious about the big concern over the 2A charger output. I set my bc6 that high but it kicks it slowly down not to long after charging starts. I do however see it seems to cut down charging time substantially.

  67. #67
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    When the current starts to decrase depends on voltage bc6 detects. It should happen at about 4.1V. Because loses in the wires there is some voltage drop so voltage at the battery side could be somewhat less than on charger side.
    Last edited by ledoman; 04-22-2015 at 10:47 AM.

  68. #68
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    We have deep electrical review of the second charger. This one is more acceptable, see:
    Review of Charger TS-1012C 2S 3A LiIon

    The third one is electricaly the same except it has interchangable plugs.

  69. #69
    mtbr member
    Reputation:
    Join Date
    Oct 2009
    Posts
    650
    3 amps, eh? That's a good one

  70. #70
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Well, in reality it is 2.6A if you have read the review. This is exactly 0.5C for a better battery packs we are using nowadays assuming 2600mAh cells. It will shorten charging time significantly in compare to tipical cheapo chargers we can get in a light sets.

  71. #71
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    BTW, the manufacturer prommised to fix voltage for all three chargers to be below 8.45V. I'm repeating this just we don't forget.

  72. #72
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Here we have review of the third charger.

    Review of Charger TS-2012H 2S 3A LiIon

    Now we need to decide which would be the most suitable for us to make some kind of group buy. Prices should stay below $10.

  73. #73
    mtbr member
    Reputation:
    Join Date
    Aug 2011
    Posts
    747
    Looks impressive, especially for that price, ledoman.

    Gotta love those plastic cooling fins too.

    Does this version come with all those plugs, or just the one appropriate for destination country?

    I'd be in for a NA version.

    Now you really gotta come up with a quality battery case, ledoman.

  74. #74
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Andy, yes the model TS-2012H is coming with all four plugs included. Of course it is the most expensive of three.

    Do you know the way we could make a poll to vote which version we should choose? We need to acomplish 200 pieces batch. If we chose fixed plug, we can order different plugs, only it has to be 200 pieces in one order.

    Will do something on BLF, too.

    Yes I was working on the battery case to be improved, but manufacturer of current BC-2 is not wiling to make any changes. They have thousands in stock and want to sell those first. They said maybe in the future..... We would need to find completly new manufacturer, but this is pretty hard work from that distance.

    PS. what is NA version?

  75. #75
    mtbr member
    Reputation:
    Join Date
    Aug 2011
    Posts
    747
    Thanks ledoman.

    NA = North America (USA + Canada)

    Dunno whether this particular feature is active on the version of V-Bulletin in use here on MTBR (because seems some HTML code has been disabled), but if you Go Advanced, the last of Additional Options is Post a Poll.

    You might also want to drop a link in Bike Forums, under Electronics, Lighting, & Gadgets

  76. #76
    mtbr member
    Reputation: garrybunk's Avatar
    Join Date
    Feb 2014
    Posts
    1,745
    Anybody wanting to comment / post questions to HKJ can do so at the BLF posting.

    I've just posted and received an answer concerning the lack of termination by the charger.

    -Garry

  77. #77
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    HKJ has done test/review of a tipical cheapo charger many people is using. They tipicaly comes with light sets. You can read it here:Review of WJT-0068 2S 1A LiIon

  78. #78
    RAKC
    Reputation: tigris99's Avatar
    Join Date
    Aug 2012
    Posts
    7,146
    Ok ledoman, now im actually interested in a decent charger. More and more cells (Panasonic and LG so far) go up to 4.35v. My charger does not.

  79. #79
    mtbr member
    Reputation:
    Join Date
    Nov 2012
    Posts
    802
    I was thinking if there is a reason you guys don't like a simple & small hobby charger like these:

    Turnigy B6 PRO 50W 6A Balance Charger (Blue)

    Hobbykingฎ DC-4S Balance Charger & Cell Checker 30w 2s~4s

    or a couple of others from HK. You can set the current, battery type, can do a balance charging. They might be a bit larger OTOH I find them to be likely more universal. There are also LiHV (4.35V) chargers and can still charge a 4.1/4.2V cell. My two bobs worth.

  80. #80
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    I do like them and use them (iCharger 106B+ this very moment), but compact charger is more practical like plug and play. For hobby charger you need separate power supply (unless integrated). Bit more knowledge, you have to check if the mode is corect, you need to make charging cable, etc... And lastly compact chargers are cheaper.

  81. #81
    mtbr member
    Reputation:
    Join Date
    Nov 2012
    Posts
    802
    Agree with all of that. OTOH I like the dimensions of the DC-4S (8x5x2cm) and you can use the 30W power supply from OPUS BT C3100 charger.

  82. #82
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    To bad, it looks here is not enough demand for charges. I wanted to people get opurtunity for a faster and known behavior charger, but got just few who would buy it. With Gearbest and manufacturer all was agreed for 200 pieces as a minimum order. Now the deal is all gone.......

  83. #83
    mtbr member
    Reputation:
    Join Date
    Feb 2009
    Posts
    344
    a bit late, but got here from the battery thread! I would also be interested in a relieable charger with 2A
    @ledoman: did you check hunklee's chargers? What about them? a bit pricy maybe....
    ..just ride...

  84. #84
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Yes, they are bit pricy. I don't know how they work. They should be OK, but would like to see tests like we did with 4 chargers in this thread.
    With Gearbest we estimated price below $10, unfortunately they did not decide to order 200 pcs only. I've managed to negotiate minimum order down from 1000pcs, but .....

    As said will try with Kaidomain this time. But it might take quite some time...

  85. #85
    mtbr member
    Reputation:
    Join Date
    Feb 2009
    Posts
    344
    hi - ok - thank you for your work with all these resellers to establish a good deal for the community!
    Last edited by Whitedog1; 12-22-2015 at 12:13 AM.
    ..just ride...

  86. #86
    mtbr member
    Reputation:
    Join Date
    Oct 2012
    Posts
    77
    Ill be interested in a couple of these chargers for the new 2 cell 3500mah packs, plug and play is all i really want.

  87. #87
    RAKC
    Reputation: tigris99's Avatar
    Join Date
    Aug 2012
    Posts
    7,146
    You can charge a 2 cell pack at 2amps. 1.5A is max safe charging, any more will drastically shorten the life of the cells.

  88. #88
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Well it's not really that bad. 1.5A is standard charging current not max. safe current. The cells (if we are talking about new KD pack) used are NCR18650GA which are declared for 10A discharge (even 20A for very short time). By definition since they have lower internal resistance they can stand also higher charge.
    Of course it will shorten battery life a bit, but not that much as it would for cells with higher IR. Expecialy if you take into account average users make 500 charges in a 10 years. It will age out before worn out.

    Edit: FYI 0.5C is tipical recomended charging current and 1C is tipical max. charge current for Li-Ion chemistry. Some reading can be found here: Types of Lithium-ion Batteries ? Battery University

  89. #89
    RAKC
    Reputation: tigris99's Avatar
    Join Date
    Aug 2012
    Posts
    7,146
    I was just going off specs I read for the cells. Recommended 1A charge, max .5C charge rate.

  90. #90
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    "Regarding NCR18650G-H0ANA, the charging current should not exceed 3.35A/cell." which is exactly 1C.
    Source: http://www.nkon.nl/sk/k/ncr18650ga.pdf

  91. #91
    RAKC
    Reputation: tigris99's Avatar
    Join Date
    Aug 2012
    Posts
    7,146
    Ah well there we go, can charge higher on these. That actually makes me happy, I can speed up my charge process for my ncr18650ga that I use in my fenix case. May have to get a couple of those packs if they are lighter than cells + fenix case.

  92. #92
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Another interesting datasheet: https://www.master-instruments.com.a...t_file/63606/1 But we should discuss it in another thread. I might open new one when pack arrives for test.

  93. #93
    mtbr member
    Reputation:
    Join Date
    Oct 2012
    Posts
    77
    im currently using this charger to charge my current 2 cell 3400mah battery packs, will this be fine for the 2 cell 3500mah packs?

    8 4V Charger Intelligent Smart 1 5A FOR 7 4V 7 2V LI ION Lipo Battery AUT5521 | eBay

    Cheers

  94. #94
    mtbr member
    Reputation:
    Join Date
    Aug 2013
    Posts
    829
    Yes.

  95. #95
    mtbr member
    Reputation:
    Join Date
    Aug 2007
    Posts
    154
    Any news regarding Kaidomain ordering the chargers? I think my charger is showing signs of retirement, so I am looking for new one.

  96. #96
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    No, they want to finish their job on battery packs first. Since we are from the same country I might help you for temporary solution on private.

  97. #97
    mtbr member
    Reputation:
    Join Date
    Jul 2015
    Posts
    183
    Do you have a specific charger thread? I can't seem to find it, so I'll post this here, and see what happens

    Other than the low quality build, ( which can be worked on if needed), those chinese chargers are unsafe because they give varying voltage outputs.

    But what if we use this?
    Name:  Izrezak.PNG
Views: 619
Size:  9.2 KB

    Its very easy to make, quite cheap, and you can adjust the output voltage to desired 8,4V, and then either use a fixed value resistor, or just leave the variable, but don't touch it.

    Since the input/output voltage difference is less than 10V, the LM is good for up to 4,5A, which is a overkill. Just need a heat sink and it's good to go...
    Last edited by ChILd_ReBoRn; 01-14-2016 at 03:02 AM.

  98. #98
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    OK, lets try to discuss it here Would you try to edit your post so the picture would show as in previous thread? It is easier when you look at it.

    Do you possibly know what is efficiency of such circuit and how big it would be?

    Normaly the chargers we use goes up to 3A. This is also the current I'm going to try to work out with Kaidomain and some manufacturer behind. No garanties I would succede, though. The question is do we need heatsink at that current.

    Of course the cheapo troublesome chargers are around 1A so no heatsinking would be needed.

    Next, what would be the cost for such device? It should not be to high. Maybe we should convice some chinese to produce them.

  99. #99
    RAKC
    Reputation: tigris99's Avatar
    Join Date
    Aug 2012
    Posts
    7,146
    This is the closest thing to a charger thread you'll find. There is plenty of safe and cheap chargers out there. Just a matter of checking output voltage. As we are learning, if the sticker on them has a red wording on it, its the ones that will cause problems. Haven't found any others that cause issues or run high on voltage of the several charges I have. And I use them all the time. Its the battery packs that make the situation dangerous. If charger voltage is too high (or poor quality, unbalanced pack) and the protection doesn't cut off, the pack goes exothermic. So check charger voltage and avoid the really cheap light/pack combos and you'll be fine.

  100. #100
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Tig, there might be usable and cheap chargers but safety depends also on mains voltage. Based on HKJ test (Review of WJT-0068 2S 1A LiIon) those are more or less danger for 220V at least. I don't say you should not use them, but it is advised to be wached and not left alone overnight. Of course as you said if you have checked voltage output first.

  101. #101
    mtbr member
    Reputation:
    Join Date
    Jul 2015
    Posts
    183
    Q: Do you possibly know what is efficiency of such circuit and how big it would be?
    A: I can't say what is the efficiency, nor am I sure what do you mena by that. The regulation is constant, and If I interpret the data sheet correctly, it goes around 0,1% in variation, depending on the load change. The size would mainly depend on the builders profficiency in making the circuit board, and/or the heatsink size.

    Q: The question is do we need heatsink at that current. (1A)
    A: I'm affraid we do. cheapo chargers that use 1A are mostly the ones with troublesome voltage output, and 1A is not all that huge current, but it's far from neglectable, BUT, if I'm correct, the LM dissipates heat depending on the correlation of input/output voltage, so in our case, if we have a 10,3V charger, and we want to reduce that to 8,4V, that gives a difference of 1,9V. The power that the LM has to dissipate through heat is (P=UxI) 1.9Vx1A=1,9W which isn't all that much, so we would need a smallish heatsink, say 2x3cm, if any . As the current rises, so does the power, at 3A it would be 5,7W, so we would probably need a heat sink, just to be on the safe side. Can't really say without an experiment. The good thing is that the LM has thermal protection, so it cuts out if it gets to hot, which means a droput in charging voltage (dunno if that affects the panny cells in any way if the charge voltage is lower than 8,4V). Heat sink even if it's an overkill helps us to avoid dropouts.


    Q: what would be the cost for such device?
    A: dirt cheap

  102. #102
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Then I would suggest you to make prototype or the one below would be usable?


    Name:  s-l500.jpg
Views: 339
Size:  24.2 KB

  103. #103
    mtbr member
    Reputation:
    Join Date
    Jul 2015
    Posts
    183
    about that reviewed charger. As I noticed, the only problem is the voltage spike, and connection of the high/low voltage side.

    That's very easy to fix. Just take a hot glue gun, and make a barrier between two sides. That would effectively prevent any possible current jumps

  104. #104
    mtbr member
    Reputation:
    Join Date
    Jul 2015
    Posts
    183
    Quote Originally Posted by ledoman View Post
    OK, lets try to discuss it here Would you try to edit your post so the picture would show as in previous thread? It is easier when you look at it.

    Do you possibly know what is efficiency of such circuit and how big it would be?

    Normaly the chargers we use goes up to 3A. This is also the current I'm going to try to work out with Kaidomain and some manufacturer behind. No garanties I would succede, though. The question is do we need heatsink at that current.

    Of course the cheapo troublesome chargers are around 1A so no heatsinking would be needed.

    Next, what would be the cost for such device? It should not be to high. Maybe we should convice some chinese to produce them.
    Quote Originally Posted by ledoman View Post
    Then I would suggest you to make prototype or the one below would be usable?


    Name:  s-l500.jpg
Views: 339
Size:  24.2 KB
    what are the specs of the one you posted?


    I can make a prototype, will do my best to make one next week if I can find the time.

  105. #105
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Quote Originally Posted by ChILd_ReBoRn View Post
    about that reviewed charger. As I noticed, the only problem is the voltage spike, and connection of the high/low voltage side.

    That's very easy to fix. Just take a hot glue gun, and make a barrier between two sides. That would effectively prevent any possible current jumps
    Maybe you and me would do that, but not the average user who thinks plug&play. It is not danger to me (I woudn't use it anyway) but for unaware users. You have to think of other people.

    About DC-DC converter you have link poped on the picture.

  106. #106
    mtbr member
    Reputation:
    Join Date
    Jul 2015
    Posts
    183
    the prefabricated regulator you posted is so cheap, that I would use more in the fuel costs to acquire the elemnts, than the finished product is worth. It uses a simmilar IC, but works non the less. It can take up to 15W with the heat sink included, so for a difference of 1,9V, it should barely get warm

  107. #107
    mtbr member
    Reputation:
    Join Date
    Jul 2015
    Posts
    183
    I'm about to order this:

    Turnigy B6 PRO 50W 6A Balance Charger (Blue) (EU Warehouse)

    it looks great, has got all the functions I need, but just one question, what kind of a power supply do I need? Can I use an old printer adaptor, or say, PC power supply?

    I wouldn't want to order it, just to find out I need a ton of money for a power supply

  108. #108
    mtbr member
    Reputation:
    Join Date
    Aug 2013
    Posts
    829
    Input voltage is specified right on the page you've linked. You can use any suitable PSU capable to provide current you need for particular task...

  109. #109
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Yes I'm using an old 18V 3A IBM Thinkpad power supply to run iCharger 106B+. Of course it lacks of power, but I seldom need much more.

  110. #110
    mtbr member
    Reputation:
    Join Date
    Jul 2015
    Posts
    183
    excellent. I'm pretty sure I'll take that turnigy. I have a friend who needs it too for charging his airsoft gun battery, so we would split the cost. Shipping is only 5,65$, and the item is 22,7$. That's under 30$...

  111. #111
    mtbr member
    Reputation:
    Join Date
    Jul 2015
    Posts
    183
    Double post, sorry

  112. #112
    mtbr member
    Reputation:
    Join Date
    Jul 2015
    Posts
    183
    But this is even better

    https://www.pololu.com/file/download...?file_id=0J525

    even cheaper

    Just one more question, the charger uses max current that the power supply needs?

    If, for instance I have a supply that gives our 9V and 2A, and I want tocharge something that would normally require 4A, would the charging be done with 1,9A but it would take considerably longer, or would the charger try to get all 4A from the supply thus burning it up in process?

  113. #113
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    IMAX B6 unless geniue are bad copies I would not use. There is plenty of them on eBay for cheap.

    For your question you should already know the answer Pin - looses = Pout

  114. #114

  115. #115
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Buy one of the Turnigys and you are on the safe side

  116. #116
    mtbr member
    Reputation:
    Join Date
    Jul 2015
    Posts
    183
    Was thinking the same thing

  117. #117
    mtbr member
    Reputation:
    Join Date
    Jul 2015
    Posts
    183
    Btw, when I get my ultra crappy ultrafire pack, would it be wise to cut it open, and solder a 3 pin balance plug? Since they are crap from beginning, just to make the best of them. The charger balance plug is protected by a plastic fin, so you can't plug it the wrong way, and I believe that the pins on the charger correspond the wire colors on the male plug? I wouldn't want to solder black/red/yellow as -/+/ballance, jus to find the pins on the charger to be different.

    Is it safe enough to put the battery pack in a metal pot with a lid on it? And charge it over a stove? Just to be on the safe side? The pot can't catch fire, and the lid would help to contain the fire

  118. #118
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    When you got the stuff and report it here. We will let you know about solution or on private if you wish. It was already discussed how to connect everything in this thread http://forums.mtbr.com/lights-night-...gb-982688.html I think.

  119. #119
    mtbr member
    Reputation: garrybunk's Avatar
    Join Date
    Feb 2014
    Posts
    1,745
    Quote Originally Posted by ledoman View Post
    Then I would suggest you to make prototype or the one below would be usable?


    Name:  s-l500.jpg
Views: 339
Size:  24.2 KB
    This thread on using a CC/CV charger module over at BLF might be helpful.


    -Garry
    "My Bike Lights" Thread on BLF teardowns, measurements, and beamshots. Moving my photos, PM or post up if you can't see them.

  120. #120
    mtbr member
    Reputation:
    Join Date
    Jul 2015
    Posts
    183
    So i ordered the turnigy charger. It should be good for 18650 cells, but as some forums claim, the cutout voltage should be reduced to 4,1V. Not sure why, as proposed by some forum members, some Li ION cells have a nominal voltage at 3,6V, and cutout at 4,1. The 4,2V cutout reduces lifespan of the batteries by 50%.

    If my memory serves me, panny cells should work fine one 3,7/4,2 V

  121. #121
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    I'm not quite shure but AFAIK Li-Lo cells has lower charging voltage while Li-Po/Li-Ion has 4.2V, some are designed even up to 4.35V.
    If you want to learn about batteries take a look educational links in this thread: http://forums.mtbr.com/lights-night-...nd-997165.html

    And yes if you are talking about Panasonic NCR18650B they are up to 4.2V. For our (cycling) purposes there is no need to take much care about prolonging battery life charging to lover voltages, while it is good to do, but not mandatory.
    Last edited by ledoman; 01-16-2016 at 04:35 PM.

  122. #122
    mtbr member
    Reputation:
    Join Date
    Aug 2013
    Posts
    829
    Quote Originally Posted by ChILd_ReBoRn View Post
    So i ordered the turnigy charger. It should be good for 18650 cells,
    Not really. You'll have to charge them one-by-one, or make some balancing harness etc. It's main purpose is charging battery packs, not cells. And there's plenty of dedicated chargers for 2, 4 or more separate cells available...

  123. #123
    mtbr member
    Reputation:
    Join Date
    Jul 2015
    Posts
    183
    Well, were talking about charging battery packs, consisting of 4 18650 cells

    7,4V, 6800 mAh. Should be good to go, plus it's got balancing plugs, and I intend to add balancing plug to the cheap chinese pack...

  124. #124
    mtbr member
    Reputation:
    Join Date
    Jul 2015
    Posts
    183
    Feeler thread about 8.4V 2A Li-Ion charger for 2SxP battery packs-img_20160121_131958-1024x575.jpg

    This should be a good power source for my turnigy charger.. It goes up to 6A, so I can charge variety of batteries, and I payed 5€ for it

  125. #125
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Yes this should be more than enough for any 2S battery pack charged over your Turnigy charger. You have probably obtained this power adapter localy from some old notebook.

  126. #126
    mtbr member
    Reputation:
    Join Date
    Jul 2015
    Posts
    183
    Yeah, Local flea market. Got a compact PC power supply. Figgured it would be better since it's got active cooling via a fan, but it didn't work. All I got was 1V out of it. So I returned it, and found a fujitsu adapter 18V/4,2A, and this. So I took this. It should work cooler on 3A, than the other one.

  127. #127
    mtbr member
    Reputation:
    Join Date
    Jul 2015
    Posts
    183
    So a quick question for all of you. If my charger has a setting for a cut off capacity, and I set it at 6800mAh ( for the 2S2P panasonic pack), what will happen if I charge the cheap chinese pack which is also 6800 in theory, but only 2400mAh in real life? Will the charger stop charging when the current drops low enough, or will it continue to charge it up to the cut off level, thus burning down my house?

    edit:

    found my answers.....nothing will happen. if the charger is fully functional, it will stop charging at 1/10 value of the charging current

  128. #128
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    As I told you it stops charging at 1/10 of starting current at whatever capacity it reach, but below safety point you have set in settings. Answer is based on fact you are using Turnigy hobby charger.

  129. #129
    mtbr member
    Reputation:
    Join Date
    Jul 2015
    Posts
    183
    I just edited the post and saw you replied. thanks for your info. Somebody should make an 18650 monument for you...using old cells

  130. #130
    mtbr member
    Reputation:
    Join Date
    Jul 2015
    Posts
    183
    I should really get some sleep. How safe is it to leave the discharge function over night? the battery is in a ceramic pot on my balcony. The discharge current is 0,6A. The charger will shut off automatically. Should be no problem...

  131. #131
    mtbr member
    Reputation: garrybunk's Avatar
    Join Date
    Feb 2014
    Posts
    1,745
    With a quality charger/discharger and quality cells I would not worry at all about leaving it. The discharge process just stops and does not go into a charge mode without you telling it to.

    -Garry
    "My Bike Lights" Thread on BLF teardowns, measurements, and beamshots. Moving my photos, PM or post up if you can't see them.

  132. #132
    mtbr member
    Reputation:
    Join Date
    Jul 2015
    Posts
    183
    Still alive . The discharge stoped ad 6,37V. Or 6,73V. I forgott. Damn it. Anyhow, I expected it to stop at 6V. Will try to discharhe some more when I get home. Maybe the charger stopped after some time.

  133. #133
    mtbr member
    Reputation: garrybunk's Avatar
    Join Date
    Feb 2014
    Posts
    1,745
    It probably stopped at 6.00v under load and bounced up to 6.xx after cutting off. (?) If that's what happened that's normal.

    -Garry
    "My Bike Lights" Thread on BLF teardowns, measurements, and beamshots. Moving my photos, PM or post up if you can't see them.

  134. #134
    mtbr member
    Reputation:
    Join Date
    Apr 2012
    Posts
    1,810
    Yes, Garry is correct. Hobby charger is showing actual voltage. At rest after discharge stops batteries gets back some voltage. This is because chemistry inside when ions inside battery become evenly spreaded.

    ChILd_ReBoR, you didn't tell what was the result of discharge process, how many mAh you've got?

  135. #135
    mtbr member
    Reputation:
    Join Date
    Jul 2015
    Posts
    183
    I wrote it in the other thread. As I was fiddling with the charger, I stopped the discharge process twice, so the total mAh discharged would be around 2500 mAh, but. I'll charge them up today, and see how much will fit inside

  136. #136
    RAKC
    Reputation: tigris99's Avatar
    Join Date
    Aug 2012
    Posts
    7,146
    My charger shows stopping voltage and sits there till I hit the button to check it. So whatever voltage it stops at whole being charged or discharged is what shows. Didn't know if that was a thing for all chargers or just some. Using a BC6 charger that I kept from my rc days cause it comes in handy for alot lol.

Similar Threads

  1. Charger for lFlex battery packs?
    By piesoup in forum Lights DIY - Do It Yourself
    Replies: 15
    Last Post: 03-14-2013, 06:57 AM
  2. Charging MS li ion packs with a Hobby charger.
    By the mayor in forum Lights and Night Riding
    Replies: 10
    Last Post: 02-14-2013, 04:11 PM
  3. Turnigy charger- can you use it to monitor charge level of battery packs?
    By Ofroad'bent in forum Lights DIY - Do It Yourself
    Replies: 8
    Last Post: 12-11-2011, 05:12 PM
  4. Help with DIY battery packs
    By mercman in forum Lights DIY - Do It Yourself
    Replies: 6
    Last Post: 10-16-2011, 05:36 AM
  5. Battery packs, chargers, Balancing etc
    By Goldigger in forum Lights DIY - Do It Yourself
    Replies: 25
    Last Post: 01-27-2011, 10:30 PM

Members who have read this thread: 0

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2019 VerticalScope Inc. All rights reserved.