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  1. #1
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    Question low voltage cut off battery question

    I have 2 pairs of 2s lipos, one pair the lvc cuts in at 3.6v and other pair it kicks in at 3.9v
    Any idea what would cause the two pairs of batteries to trip the lvc at different voltage amounts?
    Do I just have a bad set of batteries, only difference between pairs of batteries is one is the hard case other isn't.

  2. #2
    RC Turnbuckle Jr.
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    A simple question, how do you know the LVC is kicking in at those voltages?

  3. #3
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    If you are using them in a stock Summit, this is 100% normal. The lower battery feeds the motor, servos, and LED's. The higher battery feeds only the motor.
    Whatever it is I just said... I could be wrong.

  4. #4
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    Jakey: After lvc kicks in - 50% power, i put them on the charger and it shows the voltage of battery.

    Jimmy: Perhaps I asked question wrong, I have 4 batteries. All 4 for are 5000mah 25c.
    On set I get 10 minutes of run time before lvc kicks in. These drop to 3.9v and 3.8v
    Other I get 35 minutes of run time before lvc kicks in. These drop to 3.6v and 3.5v

  5. #5
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    It's your 10 minutes batteries pair new? If there are a few cicles in this lipos, they can go low voltage more easy. Just keep using them to see if they start to last long.
    Summit, dewalt 12v, 18/68 gear, T-bone skids

  6. #6
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    Quote Originally Posted by egnjohn View Post
    Jakey: After lvc kicks in - 50% power, i put them on the charger and it shows the voltage of battery.
    That's what I was wondering about. By the time you get the pack(s) out of the truck and hooked up to a charger, the pack can readily rebound 200 to 400 mV from what it was when the LVC kicked in.
    Last edited by Jakey; 02-03-2013 at 06:51 PM.

  7. #7
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    Quote Originally Posted by egnjohn View Post
    I have 2 pairs of 2s lipos, one pair the lvc cuts in at 3.6v and other pair it kicks in at 3.9v
    Any idea what would cause the two pairs of batteries to trip the lvc at different voltage amounts?
    Do I just have a bad set of batteries, only difference between pairs of batteries is one is the hard case other isn't.
    I asked the same question to my friend the other day and he said the batteries will read less voltage when 'under load'
    One pair might just not be as good as the other pair under load.

  8. #8
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    egnjohn, I'm guessing they are different brand lipo.
    Problems.The manual's good starting point. Simple

  9. #9
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    All Lipos are venom 5000mah 25c. One set are green and other set is red. The red are hard case.
    I got my summit and the green set(10 minutes run time) a few days before christams.
    I got the red set (35 minutes run time) a few days after new years.
    The green pair lasted around 35 minutes for about 5 runs. Then the run time droped to be only 10 minutes.
    I have tried charging them at different charge rates 1.5a, 3.0a, and 5a. My thought was 5a was to fast of charge rate for them, but slower charge rate didnt make a difference.

  10. #10
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    5 amps is only a 1c charge rate that's not to fast at all I have charged my gens ace at 10a before. What charger are u using and what do you have the LVc set at?

  11. #11
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    I am using Duratrax Onyx 245 charger. The lvc is the one built into the ex2 speed controller. I have no idea what the lv cut off is on it.

  12. #12
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    A $5 or less cell checker off from eBay can cure that... I always suggest getting one so you can monitor the health of your LiPo pack.

    If the two with only 10 minutes of run time are that new, I am afraid that they are junk... I would contact the seller or manufacturer about a replacement.

    Once a pack is only holding 65% of its stated capacity it is no longer safe to use.
    Whatever it is I just said... I could be wrong.

  13. #13
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    I thought the packs were bad. I looked at the packs and there is a sticker on one of them that says "if sticker removed warranty void". The sticker is missing from the second pack, must have fallen off from getting wet. So looks like I can only return one them.

    I will definitely get a cell checker. Do you know what the lvc amount is on stock speed controller?

    Thank you everyone for your help.
    Last edited by egnjohn; 02-05-2013 at 04:09 PM.

  14. #14
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    yeah i have been trying to find out also what the lvc is on the stock summit ESC. I know at some voltage it cuts throttle to 50% to let the driver know the final cut off voltage is near. Was just wondering what both these limits are.

  15. #15
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    HEY, PEOPLE! Who can say me why EVX-2 with LVD is cutt-off LiPol batteries on 3,8V per cell? It must be 3.2V! It's mestake in ESC or in firmware!
    Why I can put NiMh batteries after EVX-2 is flashing "LiPols are discarged"? It's problem too!
    Why Traxxas didn't do nothing with it?
    I don't understand. I write to Traxxas support:

    "Hello. I have traxxas Summit, it's awesome car, thank you for made it.
    But I have some questions about ESC EVX-2 with LVD.
    1. If I go with Stock NiMh 8.4 batteries in normal (red lamp) mode,
    all good. But if I put 2 pcs 2S 5000mAh 30C LiPol's batteries and
    program ESC to "green" LiPol mode ESC have cut off half of LiPols at
    3.8V. When i charge it at home they take 2500mAh each. How I can
    program the ESC to LiPol cut off at normal voltage?

    2. And second problem. If Summit go at LiPol (in "green light" mode)
    batteries ant ESC cut off and flashing "discarged" I take off LiPol's
    and want go at stock NiMh. But if I put NiMh after LiPol's and power
    on ESC it flashing "discarged" and not give me to change "gleen light"
    mode to "red light" for NiMh. It's normal? I think it's wrong
    construction of ESC or bad firmware or other ting. Maybe you can say
    me, how I can fix this problems?


    P.S. My batteries are good and have no problems at other cars and
    they take 5000mAh each from charger.

    Thank you very much for Summit! I hope all problems will be fixed. Thank you.
    Danil Bogdanov."


    But they answer me:
    "Hello,

    First try installing the LiPo batteries and switching to non LiPo mode. Once it has been changed, immediately install your NiMh packs. If that does not fix the issue you will need to replace the ESC. Where are you located and where did you purchase the truck?

    Best regards,
    Steve Lindholm
    Traxxas Customer Service

    Please include all previous e-mails in your response to prevent delays in receiving support.

    If you need further assistance, please contact our Customer Service department Monday through Friday, 8:30am to 9:00pm Central Time at one of the following numbers:

    US Customers 1-888-TRAXXAS (Toll Free)
    Outside of US 001-972-265-8000"


    I write ONCE MORE:
    "Yes, with charged LiPo batteries it swiched to "red" and "green" mods.
    But if LiPo are discharged in "green" mode ("Discharged" for EVX-2 is
    3,8V it's NOT normal) and I try swich to "red" mode or power off EVX-2
    it's nothing. And if I power off it while disconnect the "discharged"
    LiPo and Put charget NiMh (8,6V stock batteries) and put EVX-2 ON, it
    is continue flash "discharged" and don't give me change "green" mode
    to "red", i think this is NOT normal too. And how I ask before: How I
    can program the ESC to LiPol cut off at normal voltage (3,2V to cell)?
    AND: I put NiMh after LiPol's and power on ESC it flashing "discarged"
    and not give me to change "gleen light" mode to "red light" for NiMh.
    It's normal? I think it's wrong construction of ESC or bad firmware or
    other ting. Maybe you can say me, how I can fix this problems?

    Summit was buyed in Russia and I locate in Russia Moscow city too.
    Number of Summit is A2388566
    I think all problems with my EVX-2 are with ALL EVX-2, because my
    friends with Summit too say me that. Maybe try to fix firmware?

    Thank you. Best regards, Danil Bogdanov."


    But I really don't understand why nobody don't ask about it at Traxxas? EVX-2 working WRONG! Isn't it???

  16. #16
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    No, it is not.
    3.2v/cell is considered to be too low by many. 3.8v/cell is on the high side... which leads me to these questions:
    How you were driving it?
    What was the weather like?

    There is a video on YouTube showing how to switch LiPo mode off with NiMh batteries.

    EDIT:
    Found the video...

    Last edited by Jimmie Neutron; 02-21-2013 at 03:07 PM.
    Whatever it is I just said... I could be wrong.

  17. #17
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    Quote Originally Posted by Jimmie Neutron View Post
    If you are using them in a stock Summit, this is 100% normal. The lower battery feeds the motor, servos, and LED's. The higher battery feeds only the motor.
    The batteries are wired in series into the esc, how would one battery run part of the system and the other run the rest?

    I run lipo alarms set to 3.3v and my 5amp batteries run over 45 minutes. My 8.2amp batteries last longer than I'm willing to drive.

    The op needs to test his batteries in another car to see if the batteries are faulty.
    He could have a faulty motor that is drawing too much power and causing the LVD to kick in, or the esc is faulty.
    Last edited by Zepher; 02-21-2013 at 03:29 PM.
    ERBE, ERBE, Summit, Slash 4X4, Bandit,

  18. #18
    RC Turnbuckle Jr.
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    Quote Originally Posted by Zepher View Post
    ... I run lipo alarms set to 3.3v
    That is a little low for good, long-term battery pack health.

  19. #19
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    Quote Originally Posted by Zepher View Post
    The batteries are wired in series into the esc, how would one battery run part of the system and the other run the rest?
    Because the internal BEC only pulls from one battery.
    You can have two batteries ran in series and only pull half the voltage of the battery system from one battery.

    You may be thinking of parallel systems... in those if you pull from one you are pulling from both.
    Whatever it is I just said... I could be wrong.

  20. #20
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    what is the best cutoff?

    I just looked at some diagrams and see that the BEC is only off of one battery and motor pulls from both.
    It looks like you can turn on the car with only one battery attached.
    Last edited by Zepher; 02-21-2013 at 05:57 PM.
    ERBE, ERBE, Summit, Slash 4X4, Bandit,

  21. #21
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    Quote Originally Posted by Jimmie Neutron View Post
    No, it is not.
    3.2v/cell is considered to be too low by many. 3.8v/cell is on the high side... which leads me to these questions:
    How you were driving it?
    What was the weather like?

    Why 3.8V/cell is normal? At all of my another cars cut-off is normal at 3.2v/cell and my friends with different cars have cut-off at 3,2V/cell. Why VXL cut off at 3.2V/cell???

    I'm going in Russia:
    Photo https://plus.google.com/photos/10382...J2q6_X-haui2QE
    Video: http://www.youtube.com/watch?v=7RdHz...JuBAiQ&index=1
    Last edited by Danil_rus; 02-22-2013 at 12:47 AM. Reason: Mistakes

  22. #22
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    I did not say 3.8v/cell was normal.
    Whatever it is I just said... I could be wrong.

  23. #23
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    Quote Originally Posted by Jimmie Neutron View Post
    3.2v/cell is considered to be too low by many.
    What is it? Is 3.2V per cell is TOO LOW FOR LiPol??? I think it TOO GOOD CUT-OFF AT 3.2V PER CELL!
    Last edited by Danil_rus; 02-22-2013 at 04:50 PM.

  24. #24
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    Today I have answer from Traxxas:
    "Hello

    Traxxas handles international warranty issues through our international importers. Please contact the local hobby shop where you purchased the vehicle and see if they can help. If they cannot, ask them to contact their authorized Traxxas importer where they purchase their Traxxas products. You may need to send the ESC to them for evaluation."


    And I answer them:

    "What will change? There is a stupid solution constantly blinking mode
    "discharged" http://www.youtube.com/watch?feature...&v=oiYypUV9sIg
    but there is no solution to the problems with the cut-off 3.8V. It
    might be worth to officially recognize the problem and to withdraw all
    controls made with this problem?"


    Waiting...

  25. #25
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    All of my 5000mAh take 2500mAh from charger after "discharged" mode of EVX-2

    I think EVX-2 have a many problems from TRAXXAS!!!
    Last edited by Danil_rus; 02-22-2013 at 05:07 PM.

  26. #26
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    need some help,please. im running two 775 with the kershaw set up . it was running well. this is a summit that im working on and its over a year old. it stoped in its tracks motors stoped spinning but i still have steering and the low high. i hooked up the two motors from two older 775 with dual leads. the leads that were not pluged in to anything were not covered and i was in the snow,also it is flashing green

  27. #27
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    Quote Originally Posted by Danil_rus View Post
    All of my 5000mAh take 2500mAh from charger after "discharged" mode of EVX-2

    I think EVX-2 have a many problems from TRAXXAS!!!
    Why don't you answer my questions in post #16?

    Quote Originally Posted by my buggy View Post
    need some help,please. im running two 775 with the kershaw set up . it was running well. this is a summit that im working on and its over a year old. it stoped in its tracks motors stoped spinning but i still have steering and the low high. i hooked up the two motors from two older 775 with dual leads. the leads that were not pluged in to anything were not covered and i was in the snow,also it is flashing green
    Try resetting your transmitter, rebinding, and reprogramming the ESC.
    Fast green means throttle neutral is out of adjustment.
    Whatever it is I just said... I could be wrong.

  28. #28
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    Answer from Traxxas:
    "Hello,

    Thanks for your comments and input. Unfortunately I do not have a different answer for you.

    Best regards,
    Steve"

    It's the end...

    Jimmie Neutron what's the question, friend? I answer in post #21 or not? Maybe I dont understand some english words? let's try ask querstion once more?

  29. #29
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    How you were driving it?
    What was the weather like?
    Whatever it is I just said... I could be wrong.

  30. #30
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    Im Driving in Russia. Drive in normal mode 50% high gear, 50% low gear. Weather now is snow about -5 -8 degrees by celsium.












  31. #31
    RC Turnbuckle Jr. jamann's Avatar
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    Lipo batts do not like the cold very much
    Do not like it at all really.so my guess is
    They are sagging enough to trigger the lvd under load.but rebound back up at rest.are these new batts or older packs?


    Sent using lipo power
    Mountains cant stop me
    they have tried

  32. #32
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    At another cars all right at this LiPol and at that weather. Cut-off at 3,2V/cell. It NOT weather

  33. #33
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    I don't understand, guys, do you have EVX-2? Do you run at LiPols? Do you have LVD? When YOU have cut-off on it???

    I also can not understand why all the only reason? Really hard to tell just how are you? Or do you simply just write something or suggest you go? There is a specific problem has been discussed for almost a week, but all I see is a stupid argument and speculation. Can somebody tell how his EVX-2 work?

  34. #34
    RC Turnbuckle Jr. jamann's Avatar
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    Sorry for wasting your time.mine has had no issues, owned it for some time.
    many other people have no major issue.
    Are your other cars 15+ pounds before you added fpv gear and snow load.
    Again sorry for wasting MY time bothering to reply.


    Sent using lipo power
    Mountains cant stop me
    they have tried

  35. #35
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    "Are your other cars 15+ pounds before you added fpv gear and snow load."
    Don't understand. FPV have ownn 3S LiPol battery 1450mAh.
    Slash 4x4VXL have normal 3,2V/cell cut-off.

  36. #36
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    Okay it's not weather, the esc probably has a high cutoff value, and under load your batteries are dipping below that voltage thus cutting power, either call traxxas and get a replacement or turn the Lvd off and buy an LVA (low voltage alarm) off flea bay for $5 and plug it into the battery that powers the servos, (the plug with the red label on it. Set the value of the LVA alarm to 3.2vpc and voila. When the batts reach that level a Loud alarm will sound and you will know its time to bring her in. Also the LVA will show each cell voltage. Can't we all just get along, god bless and good luck.


    Sent from my iPhone 5

  37. #37
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    Yes, today I buying On Board Lipoly Low Voltage Alarm (2s~4s). EVX-2 don't have another way to work LVD. Thanx to all.

    I apologize if I offended anyone.
    Last edited by Danil_rus; 02-24-2013 at 10:19 AM.

  38. #38
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
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    I can guarantee you that it is the weather.
    The cut off on the other ESC's are way too low.

    Accept it or just move on.
    Whatever it is I just said... I could be wrong.

  39. #39
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    I know when I ran last week when I got cold here in Florida it was probably 50 degrees my batteries were in the cold garage, charged up night before, and I was hitting the cutoff on my MMM earlier than I normally would, since then haven't had the problem since its warmed up. Take the advice from these guys like jamman and Jimmie they know thier stuff man.


    Sent from my iPhone 5

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