Results 1 to 6 of 6
  1. #1
    mtbr member
    Reputation:
    Join Date
    Aug 2009
    Posts
    4

    New question here. Serfas True 1500 battery/Lipo/Protection-Circuit questions...

    Hello to all,

    I got as a present an almost new Serfas True 1500 light, to be used in Night Mountain Biking.
    The battery included can support the light up to 2:30hrs which is on the limit.

    I plan to get a 2cell Lipo Battery with above 7200mAh, which may be sufficient for my needs.

    Now, I plan to keep the original battery, therefore I need to tailor the same connector for the Lipo.

    Questions:
    • Will the Serfas True 1500 work with the 2Cell Lipo Battery (from the voltage point of view), the original battery that comes is around 7.4V
    • Which connector it uses, that is, how can I order it on-line?
    • Most of the Lipo batteries I saw, do not include any protection circuit, Do I need a protection circuit for using the battery or it is only for charging it? (I plan to get also a charger, that is suitable for the Lipo)


    I have also an old MAgicShine HA-III Cree SSC P7-C (SXO) 3-Mode 900-Lumen LED I got long ago, that its batteries are dead as well. (That is, get two lipo for this purpose..)

    Do you have any advise?


    I'm new in this forum therefore be kind
    .. if this is not the correct place to post, please provide me a pointer where to do it or to read.

    Have a nice day to all...
    -- Rbid (Also Known as Ricky Marek).

  2. #2
    mtbr member
    Reputation:
    Join Date
    Jun 2007
    Posts
    521
    •Will the Serfas True 1500 work with the 2Cell Lipo Battery (from the voltage point of view), the original battery that comes is around 7.4V

    What voltage is the "2cell Lipo Battery with above 7200mAh" you plan to get. It needs to be 7.4V - same as the orig.

    Most any connector pair will work if it is specified to carry the current the light requires.

    A lot of lipo protection modules are to protect during discharge, not during charge. So you need to define what you want/need.
    Half our life is spent trying to find something to do with the time we have rushed through life trying to save

  3. #3
    mtbr member
    Reputation:
    Join Date
    Apr 2010
    Posts
    2
    Hi Rbid,

    I use the Gensace type of lipo fro here (Gens ace Lipo Battery - Gens Ace).
    I have the 7.4V lipo soft case for a majicshine at 4000mAh and it will run for around 4 hours give or take don't really check, but I use it say for 4 rides at 1 hour each and then charge as the red light on the majic shine is usually on by then.

    I change it with a multi charger that is similar to the one on the Gensace site, (You need to use a balance charger to charge the cells correctly) it is good as I can use it on 240v and 12 Volt from the car to charge if out at a race etc.

    I have also modified the battery and changed the lead from the majicshine battery and soldered it onto the lipo battery at the terminals (take the old leads off). Then I heat shrink and seal the ends with shoe glue to make water resistant.

    No protection circuit needed as the charger will do its thing.

    As for the connection for the Serfas 1500 they look the same as the Majic shine??

    Hope this helps?

  4. #4
    mtbr member
    Reputation:
    Join Date
    May 2005
    Posts
    2,234
    Quote Originally Posted by craigl View Post
    No protection circuit needed as the charger will do its thing.
    The importance of a protection circuit is not only for overcharge protection. The other important reasons for a protection circuit are over-discharge and short circuit protection. Li-Po batteries will be damaged if discharged below ~2.8Vqa/cell. Li-Po's can also provide very high current during discharge. Without some kind of protection against short circuits the will provide enough current to melt the wiring to your light.

    Protection boards are cheap and readily available. Really no reason to not add one to your battery pack.

  5. #5
    mtbr member
    Reputation:
    Join Date
    Aug 2009
    Posts
    4
    Hello to all,

    Here is a summary of what I have learned from the posts that arrived...

    Hi Craigl,
    Quote Originally Posted by craigl View Post
    I use the Gensace type of lipo fro here (Gens ace Lipo Battery - Gens Ace).
    I have the 7.4V lipo soft case for a majicshine at 4000mAh and it will run for around 4 hours give or take don't really check, but I use it say for 4 rides at 1 hour each and then charge as the red light on the majic shine is usually on by then.
    The Serfas has also a light as warning... That is good when you have your light on the handlebar (which is true for the Serfas), but I plan to put the old Magicshine on my helmet, and there I can't see if it becomes red.

    I saw in HobbyKing a kind of buzzer that emmits a warning sound when the voltage drops and the battery can be damaged... that could be a nice solution as well.

    Quote Originally Posted by craigl View Post
    I have also modified the battery and changed the lead from the majicshine battery and soldered it onto the lipo battery at the terminals (take the old leads off). Then I heat shrink and seal the ends with shoe glue to make water resistant.
    Yes, this I plan to do as well.

    Quote Originally Posted by craigl View Post
    No protection circuit needed as the charger will do its thing.
    I'm not sure about this, because short circuit or when the Lipo potential goes below some voltage can be also be damaged.. I guess that is the kind of additional protection mentioned below...

    Quote Originally Posted by craigl View Post
    As for the connection for the Serfas 1500 they look the same as the Majic shine??
    Yes, I just checked and he connector is the same, can plug the Serfas 1st quality battery into the Majicshine P7 light.

    Wmodavis,
    Quote Originally Posted by wmodavis View Post
    A lot of lipo protection modules are to protect during discharge, not during charge. So you need to define what you want/need.
    First of all, I'm new here, and I'm learning a lot. It seems that LiPo Batteries need to be protected for several factors:
    • Overcharging, (During the charge process if not done correctly)
    • If discharged below their limit as Vancbiker mentioned...
    • Is short circuited..
    • If punctured, which makes them problematic for Mountain Biking...


    Vancbiker,
    Quote Originally Posted by Vancbiker View Post
    The importance of a protection circuit is not only for overcharge protection. The other important reasons for a protection circuit are over-discharge and short circuit protection. Li-Po batteries will be damaged if discharged below ~2.8Vqa/cell. Li-Po's can also provide very high current during discharge. Without some kind of protection against short circuits the will provide enough current to melt the wiring to your light.
    Many Many Thanks, very instructive answer, this confirms more or less what I know about the batteries..

    Quote Originally Posted by Vancbiker View Post
    Protection boards are cheap and readily available. Really no reason to not add one to your battery pack.
    Can you point to a board that provides protection.. This will be helpful. From there I guess I will be able to continue.

    Have a nice day to all..
    -- Rbid (Also Known as Ricky Marek).

  6. #6
    mtbr member
    Reputation:
    Join Date
    May 2005
    Posts
    2,234
    You should be able to find one that suits you here.....

    PCB/PCM/Fuel Gauge for 7.2V(7.4V) Lithium Battery Pack

Similar Threads

  1. Serfas True 1500? Or Baja Double Stryker?
    By Muffinhead in forum Lights and Night Riding
    Replies: 9
    Last Post: 12-22-2012, 02:52 PM
  2. Baja Designs Double Stryk 1800 Lumens or Serfas True 1500
    By Muffinhead in forum Lights and Night Riding
    Replies: 0
    Last Post: 11-13-2012, 09:17 AM
  3. Dinotte XML-3 or Serfas True 1500
    By joshdurston in forum Lights and Night Riding
    Replies: 14
    Last Post: 06-09-2012, 09:23 PM
  4. Serfas True 1500
    By bluewave in forum Lights and Night Riding
    Replies: 7
    Last Post: 10-17-2011, 05:42 PM
  5. LiPo protection circuit problem
    By formantjim in forum Lights DIY - Do It Yourself
    Replies: 20
    Last Post: 02-01-2011, 09:06 PM

Posting Permissions

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