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  1. #1
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    Question How To Use a Multimeter To Check a LiPo Battery

    My hope is this gets answered...

    What do I set the multimeter to?

    What should the reading on the meter be?

  2. #2
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    DC volts.



    Above 3 volts per cell
    No more than 4.2 volts per cell
    Whatever it is I just said... I could be wrong.

  3. #3
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    Can you post a picture of your multimeter? They're not all the same...
    Make it idiot-proof and along comes a better idiot

  4. #4
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    Yep, DC Volts is what you want to use. Dial it down to the smallest volt setting you need as long as its higher than the volts you plan to read. It is a little safer to ues a lipo volt checker. If you are checking with the MM probes, be careful not to let the neg probe touch the pos probe when your checking that first cell. They will be close togather. Same goes for checking those little micto 1S batteries if you fly micro planes or heli's.

  5. #5
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    2S battery; the balance plug wires are black, blue, and red

  6. #6
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    And whats the question?

  7. #7
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    Quote Originally Posted by Honda View Post
    2S battery; the balance plug wires are black, blue, and red
    Then ignore the 3-4 connection and 3 becomes pack positive.
    The picture still works.

    Don't pay attention to wire color. They could be hot pink and green and it wouldn't make a difference.
    Whatever it is I just said... I could be wrong.

  8. #8
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    on the pic above change the yellow to blue and change green to red. Now you have pins 1(Black),2(Blue),3(Red)
    Pin 1 is pack neg, pin 3 is pack pos.
    Test probes on pin 1&2 gives you cell 1,
    Test probes on pin 2&3 gives you cell 2 reading
    Guide books aren't part of the packaging.

  9. #9
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    Ha!
    Ninja posted you for once Trax!
    Whatever it is I just said... I could be wrong.

  10. #10
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    Quick like bruce lee.
    slow electrons in the broadband in the u.k.
    Guide books aren't part of the packaging.

  11. #11
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    Charged battery 2 weeks ago. Son and I wound up not running the truck due to bad weather.

    READINGS:

    Cell 1: 5.03 black on black, red on blue
    Cell 2: 5.03 black on blue, red on red
    combined 10.12 black on black, red on red

  12. #12
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    Colors don't mean anything... what pins did you use and what balance connector do you have?

    If you are measuring correctly and the multimeter is accurate, that is one severely overcharged LiPo... and it was severely over charged for a very long time. Storage voltage is supposed to be used for anything over 24 hours.
    Whatever it is I just said... I could be wrong.

  13. #13
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    I charged the battery with the Traxxas charger that came with the truck. Unplugged the charger within 5 minutes of both lights turning green. Craftsman Digital Multimeter 82082. Placed the multimeter leads on the battery balance plug connector.

  14. #14
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    What pins did you use and what balance connector do you have?
    Whatever it is I just said... I could be wrong.

  15. #15
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    Quote Originally Posted by Jimmie Neutron View Post
    What pins did you use and what balance connector do you have?
    To charge the battery or to test the voltage?

  16. #16
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    Test voltage.

    There are different types of balance connector, as shown above.
    Whatever it is I just said... I could be wrong.

  17. #17
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    The battery is a Traxxas 2867; Traxxas Power Cell LiPo 25C 7.4V 2-cell 4200mAh. (The stock battery) I tested the battery by placing the multimeter leads on the balance connector that is sticking out of the battery. The JST-XH connector.

  18. #18
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    Ok. And where did you place the multimeter leads?
    1-2?
    2-3?
    1-3?

    Sorry for all the questions... but something is not adding up. If the charger overcharged the LiPo that badly, there is something wrong with the charger... and the charger has probably ruined that LiPo.

    Also, if the cells really are 5.03 each, total voltage should be 10.06... not 10.12.
    Last edited by Jimmie Neutron; 02-10-2013 at 07:43 PM.
    Whatever it is I just said... I could be wrong.

  19. #19
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    I'd store that puppy in an ammo box, in the garage. Sounds risky. It sounds like you have some sort of big problem, and you need to dig into it before you have really bad story to tell.

    Sent from a Galaxy S3, far....far away.

  20. #20
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    Quote Originally Posted by Jimmie Neutron View Post
    Ok. And where did you place the multimeter leads?
    1-2?
    2-3?
    1-3?

    Sorry for all the questions... but something is not adding up. If the charger overcharged the LiPo that badly, there is something wrong with the charger... and the charger has probably ruined that LiPo.

    Also, if the cells really are 5.03 each, total voltage should be 10.06... not 10.12.
    1-2 was 5.03
    2-3 was 5.03
    1-3 was 10.12

    now it's reading 4.20, 4.21,8.41

  21. #21
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    Assuming the low cut off on the ESC is working correctly. What should the cells output be when the truck shuts off?

  22. #22
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    3.4-3.6v per cell

    Your second measurement is much better!

    I still would not leave them at full voltage for more than 48 hours... I personally don't let mine stay that full for more than a half hour. lol The longer they are there, the less life you will get out of them.
    Whatever it is I just said... I could be wrong.

  23. #23
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    I'm seeing the power cut program occur at around 3.7 volts on mine. The truck still moves, but it suddenly becomes a slug. I stop right then and remove the batteries.

    Sent from a Galaxy S3, far....far away.

  24. #24
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    I haven't bought the high speed charger yet. So, I'm stuck waiting 7-8 hours for the battery to charge. When I get a good charger I'll use the discharge/storage mode.

  25. #25
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    Thanks again for all of your help Jimmy.

  26. #26
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    No problem.

    BTW: Even running them down to 4v/cell would take a lot of stress off from the cells. That way when you charge you only have to recover .2v.
    Whatever it is I just said... I could be wrong.

  27. #27
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    I realize this is a late post but is the charger being used the correct charger for LiPo's? Sounds like he may have used the stock charger designed for NiMh's.
    Rob
    P2DE Driver.

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