Page 1 of 3 1 2 3 LastLast
Results 1 to 25 of 59
  1. #1
    mtbr member
    Reputation: Ofroad'bent's Avatar
    Join Date
    Jul 2010
    Posts
    956

    Panasonic 3100 mAh on dx

    Are these the real deal?

    Barb was using one of my 1S2P battery packs on the weekend in a night orienteering race, and she said the light (Single XM-L, L-flex set on multi-level with max at 3000ma) wouldn't work on level 5 at all and started to give her a warning flash after an hour on level 4.

    I wonder if the battery pack just couldn't handle 3000 ma, or if the protection circuit in the battery pack cut in.

    I think I may need to build her another pack with more capacity, and hopefully a more generous internal protection chip. Think these will do the trick, if they are genuine?
    Genuine Panasonic 18650 3100mAh Rechargeable Battery with Protection Board - Green (Pair) - Free Shipping - DealExtreme

  2. #2
    mtbr member
    Reputation: OverTheHill's Avatar
    Join Date
    Dec 2004
    Posts
    328
    I think I've seen some recent discussion about this on CPF and/or BLF but can't remember what the general consensus was. I think it was on one of the threads about "Best 18650 to Buy" or something like that.

    I'll have a root around later and see if I can find it again.

  3. #3
    mtbr member
    Reputation: OverTheHill's Avatar
    Join Date
    Dec 2004
    Posts
    328
    I just did a quick search on CPF for "Panasonic DX" and quite a few threads came up.

    One of the things I did remember was that Panasonic only produce unprotected cells. The protection circuits are put on by someone else and the relatively cheap protected cells on DX may have genuine Panasonic unprotected cells in them but the PCs are crap (apparently).

    I guess you get what you pay for. I did see a comment from one poster on a thread that he had tested one of the DX 3100 mAh unprotected cells against a known pukka Panasonic cell and it was genuine.

    Hope that helps.

  4. #4
    mtbr member
    Reputation: Ofroad'bent's Avatar
    Join Date
    Jul 2010
    Posts
    956
    Quote Originally Posted by OverTheHill View Post
    I think I've seen some recent discussion about this on CPF and/or BLF but can't remember what the general consensus was. I think it was on one of the threads about "Best 18650 to Buy" or something like that.

    I'll have a root around later and see if I can find it again.
    So, what was the "Official CPF Best High Capacity Battery" to buy?

  5. #5
    mtbr member
    Reputation:
    Join Date
    Sep 2007
    Posts
    53
    I have four of the unprotected Panasonic 3.1Ah cells from DX. I did some capacity measurements and they are pretty close to 3.1Ah, don't remember the exact results. However, I did the measurements with brand new cells that had been charged only once and twice. The capacity was slightly higher after second charge. I discharged them individually at 1A.

  6. #6
    mtbr member
    Reputation:
    Join Date
    Mar 2006
    Posts
    477
    Here is a write up on BudgetLightForum about protected Panasonics 3100ma cells.
    "By Your Command"

  7. #7
    mtbr member
    Reputation: Ofroad'bent's Avatar
    Join Date
    Jul 2010
    Posts
    956
    They look pretty good.
    OK, now how about some decent 3400 mah cells? Anyone got a suggestion?
    Safer to buy unprotected and protect them myself?

  8. #8
    mtbr member
    Reputation: HEY HEY ITS HENDO's Avatar
    Join Date
    Feb 2008
    Posts
    713
    suggestions?, go 3P
    ...Scun.thorpe, UK

  9. #9
    mtbr member
    Reputation:
    Join Date
    Apr 2010
    Posts
    488
    Here is the 2012 battery test on CPF.

  10. #10
    A mtb rider from Isreal
    Reputation:
    Join Date
    Jul 2009
    Posts
    29
    Quote Originally Posted by Ofroad'bent View Post
    They look pretty good.
    OK, now how about some decent 3400 mah cells? Anyone got a suggestion?
    Safer to buy unprotected and protect them myself?
    1. There is no 3400Mah cells! Only 3100, from panasonic.
    2. If you build a pack, then you need Unprotected cells and then put a protection board on the hole pack.

  11. #11
    mtbr member
    Reputation:
    Join Date
    Apr 2010
    Posts
    488
    Quote Originally Posted by BUGY View Post
    1. There is no 3400Mah cells! Only 3100, from panasonic.
    2. If you build a pack, then you need Unprotected cells and then put a protection board on the hole pack.
    Now you're talking rubbish!

    Panasonic NCR18650B is a 3400mAh rated cell.

    Using protected cells in a pack means, they are all protected individually, no matter how you wire them, so common PCB is not needed if you use charger that can balance your cells and of course you wire a balance harness to the pack. Wiring cells first, than adding PCB is okay too, but there is nothing wrong with using protected cells without common PCB. Biggest problem of the packs using unprotected cells and PCB is, the PCB is not capable of balancing during recharge.

  12. #12
    A mtb rider from Isreal
    Reputation:
    Join Date
    Jul 2009
    Posts
    29
    Quote Originally Posted by Toaster79 View Post
    Now you're talking rubbish!

    Panasonic NCR18650B is a 3400mAh rated cell.

    Using protected cells in a pack means, they are all protected individually, no matter how you wire them, so common PCB is not needed if you use charger that can balance your cells and of course you wire a balance harness to the pack. Wiring cells first, than adding PCB is okay too, but there is nothing wrong with using protected cells without common PCB. Biggest problem of the packs using unprotected cells and PCB is, the PCB is not capable of balancing during recharge.
    I am out of date. Last time I build myself a 2S2P pack the 3100 wore the hist capacity cells.

    Yes you can build a pack whit protected cells but way? They are more expensive and this is not the proper way to go. Sorry but my english ist sufficient to explain properly Search this topic.

  13. #13
    mtbr member
    Reputation: mattthemuppet's Avatar
    Join Date
    Jul 2004
    Posts
    2,296
    I'd buy the plain NCR18650B if you can find them (they were in short supply last time I looked) and put your own PCB on there. If you don't mind giving up a few 100mAh, the NCR18650A are fine and you can find them from a bunch of reputable sellers. Chinaqualitygoods has decent prices and the 2900mAh cell I bought from them checked out, or you can buy from Orbtronic in the US which has decent prices and also checked out.

    Spend some time on the BLF batteries forum and you should pick up some more places to order from. I think a user called KumaBear was bringing in a whole host of different batteries, but I haven't read any feedback reports on them yet. I see no reason to play the DX lottery when there are so many other options. They lost my trust a long time ago.

    BTW, what were the cells that couldn't provide the juice?

  14. #14
    mtbr member
    Reputation: Ofroad'bent's Avatar
    Join Date
    Jul 2010
    Posts
    956
    Quote Originally Posted by mattthemuppet View Post
    I'd buy the plain NCR18650B if you can find them (they were in short supply last time I looked) and put your own PCB on there. If you don't mind giving up a few 100mAh, the NCR18650A are fine and you can find them from a bunch of reputable sellers. Chinaqualitygoods has decent prices and the 2900mAh cell I bought from them checked out, or you can buy from Orbtronic in the US which has decent prices and also checked out.

    Spend some time on the BLF batteries forum and you should pick up some more places to order from. I think a user called KumaBear was bringing in a whole host of different batteries, but I haven't read any feedback reports on them yet. I see no reason to play the DX lottery when there are so many other options. They lost my trust a long time ago.

    BTW, what were the cells that couldn't provide the juice?
    I will probably see if Ktronik still has his nice protection boards.
    After a lot of tinkering, something seems wonky with Barb's light, not the battery. The same battery runs all my other lights fine, but we get a Low Voltage warning on level 5 on hers after about 30 seconds, regardless of battery pack.

    I've been e-mailing George at TaskLED, and it sounds like I need to test the voltage across the board at the 3000ma setting and play with the low voltage warning on that light.

  15. #15
    mtbr member
    Reputation:
    Join Date
    Jul 2007
    Posts
    1,124
    I've got 2 pair of the protected cells on the way - ordered a week ago - hope to see them in another week or so. I'll report the typical discharge/charge info.

  16. #16
    mtbr member
    Reputation:
    Join Date
    Sep 2007
    Posts
    53
    Quote Originally Posted by Ofroad'bent View Post
    I will probably see if Ktronik still has his nice protection boards.
    After a lot of tinkering, something seems wonky with Barb's light, not the battery. The same battery runs all my other lights fine, but we get a Low Voltage warning on level 5 on hers after about 30 seconds, regardless of battery pack.

    I've been e-mailing George at TaskLED, and it sounds like I need to test the voltage across the board at the 3000ma setting and play with the low voltage warning on that light.
    Could it be that the threshold for low voltage is set so high that when at 3A, the battery voltage sags due to high current draw and triggers the low voltage warning?

  17. #17
    mtbr member
    Reputation: Ofroad'bent's Avatar
    Join Date
    Jul 2010
    Posts
    956
    Quote Originally Posted by [jsl] View Post
    Could it be that the threshold for low voltage is set so high that when at 3A, the battery voltage sags due to high current draw and triggers the low voltage warning?
    That was my thought. I opened the light and measured the voltage.
    Level 1-3 = 3.9v
    Level 5= 3.48 v

    There's definitely some voltage sag. Could be the battery cells (Samsung 2600mah), could be cheapo protection circuit, but the main thing I noticed is that the l-flex had pulled away from the housing, so wasn't getting proper heat sinking.

    I replaced the thermal tape, re soldered the connections for good measure, and it seems OK now.

  18. #18
    mtbr member
    Reputation: Ofroad'bent's Avatar
    Join Date
    Jul 2010
    Posts
    956
    I will still consider building a higher capacity battery pack.
    Interested to know if the PCB on these eBay batteries is decent:

    2pcs Protected Panasonic 18650 NCR18650B Rechargeable battery 3400mAh With PCB

    http://cgi.ebay.ca/ws/eBayISAPI.dll?...p:en#ht_2794wt

    They claim :"The PCB is made of Seiko stainless steel protection plate, maximum power voltage is 4.2V, the minimum voltage of 2.5V,the PCB is using 2 MOSFET version,is different with other sellers with the single MOSFET only."

    It sure would be simpler than ordering PCMs from Ktronik and wiring up unprotected cells, even though I know ktronic's boards are excellent.

  19. #19
    mtbr member
    Reputation:
    Join Date
    Sep 2007
    Posts
    53
    Since you are using 1S2P configuration and LFlex, I would simply forget individual cell protection. Configure the driver's thresholds for medium, low and cut-off to some suitable values and there should be no real risk of with ruining the cells.

  20. #20
    mtbr member
    Reputation: mattthemuppet's Avatar
    Join Date
    Jul 2004
    Posts
    2,296
    Quote Originally Posted by Ofroad'bent View Post
    I will still consider building a higher capacity battery pack.
    Interested to know if the PCB on these eBay batteries is decent:

    2pcs Protected Panasonic 18650 NCR18650B Rechargeable battery 3400mAh With PCB

    http://cgi.ebay.ca/ws/eBayISAPI.dll?...p:en#ht_2794wt

    They claim :"The PCB is made of Seiko stainless steel protection plate, maximum power voltage is 4.2V, the minimum voltage of 2.5V,the PCB is using 2 MOSFET version,is different with other sellers with the single MOSFET only."

    It sure would be simpler than ordering PCMs from Ktronik and wiring up unprotected cells, even though I know ktronic's boards are excellent.
    personally I wouldn't touch 'em with a pole, especially that that price. It doesn't matter what they say about the PCB, there's no guarantee that it will actually be that (or even a real PCB, believe it or not). Plus they don't specify the overcurrent spec or anything like that. eBay + 18650 + China = bad.

    I would trust Orbtronic (or it's eBay shop) or CNqualitygoods. I've bought and tested batteries from both places. Plenty of people have had successful orders with KumaBear on BLF too. Prices seem pretty reasonable - $12.50 for protected and $10.50 for unprotected NCR18650B. I'd be more likely to trust some random person off BLF than I would a Chinese eBay seller

  21. #21
    mtbr member
    Reputation: HEY HEY ITS HENDO's Avatar
    Join Date
    Feb 2008
    Posts
    713
    http://www.hobbyking.com

    i would go this route....
    ...Scun.thorpe, UK

  22. #22
    mtbr member
    Reputation: mattthemuppet's Avatar
    Join Date
    Jul 2004
    Posts
    2,296
    Quote Originally Posted by HEY HEY ITS HENDO View Post
    http://www.hobbyking.com

    i would go this route....
    more weight for less capacity though, which is more of an issue on the helmet that the bars

  23. #23
    mtbr member
    Reputation:
    Join Date
    Jul 2007
    Posts
    1,124
    I'm not going to run a LiPo battery for these - mainly cause I'm afraid of the damn things. I had one for a RC plane swell up on me just sitting on the bench with what was probably a 85% remaining charge.

    Anything you have to charge in a special container in case of fire isn't something I want to be carrying on my helmet or in my camelbak.

  24. #24
    mtbr member
    Reputation: Ofroad'bent's Avatar
    Join Date
    Jul 2010
    Posts
    956
    Quote Originally Posted by [jsl] View Post
    Since you are using 1S2P configuration and LFlex, I would simply forget individual cell protection. Configure the driver's thresholds for medium, low and cut-off to some suitable values and there should be no real risk of with ruining the cells.
    Not all my friends have smart chargers. For myself I can use unprotected batteries.

  25. #25
    mtbr member
    Reputation: Ofroad'bent's Avatar
    Join Date
    Jul 2010
    Posts
    956
    I got some of the unprotected 3400maH Panasonics.
    I tried them in a friend's protected 1S2p holder, but couldn't get more than 2500 maH out of them.
    I suspect it's something to do with a crummy PCM in the holder.

    I got 2550 out of one cell tested directly without PCM. Still not what I expected.
    My Accucell charger was set to discharge them to 3.0v.

    I seem to remember reading that these cells have more capacity down to lower voltages without damage. Maybe I should have tested them to lower voltage.

    This will be a PITA if I have to reconfigure my lights voltage cut-off, and suspect the PCMs I ordered from ktronic will cut off at 3v anyway.

    Any thoughts?

Page 1 of 3 1 2 3 LastLast

Posting Permissions

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