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  1. #1
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    Advice on the LVC can of worms

    I want to preface this by saying that I have read the many posts and "debates" about exactly what voltage the esc cuts to low power mode and then stage two at shut down. I am using SMC batteries that for some reason recommend "setting" LVC to 3.6volts. I just hooked up the pack to re charge it and the cells were at 3.3volts, and I had ran it till it cut the throttle.

    Im not interested in the finite details of the action of the LVC, but rather does anyone here have any anecdotal evidence that running their SMC packs with traxxas LVC being a negative? Id rather not have to waste money and time on some other bits if its all just marketing fluff or a bit if CYA from the manufacturer. How different can the chemistry of different lipos be? Ive done research unrelated to rc on batteries(for solar panels) and even at the bleeding edge of that tech there is not really any marked difference between batteries as they technology has hit a plateau.

  2. #2
    RC Champion RazorRC22's Avatar
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    Lipo packs get tired after use, just by charging/discharging, leaving fully charged, etc. -- the lower you run them down the faster they become tired. I don't think it's going to catch on fire or anything.

    Whether running them down to 3.3V increases the internal resistance 1% faster or 0.01% faster, who knows. IMO, 3.3V is really a "won't catch on fire" setting rather than a "keeps the life of your battery as long as possible" setting. I pretty much run mine down to about 3.65-3.7V, as I noticed the power loss after that.
    youtube.com/c/RazorRCvideos

  3. #3
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    Quote Originally Posted by RazorRC22 View Post
    Lipo packs get tired after use, just by charging/discharging, leaving fully charged, etc. -- the lower you run them down the faster they become tired. I don't think it's going to catch on fire or anything.

    Whether running them down to 3.3V increases the internal resistance 1% faster or 0.01% faster, who knows. IMO, 3.3V is really a "won't catch on fire" setting rather than a "keeps the life of your battery as long as possible" setting. I pretty much run mine down to about 3.65-3.7V, as I noticed the power loss after that.
    Went to the "LHS" (an hr away) and they basically said that as long as its not below 3v per cell I should be ok, and even then you can put it on nimh mode to get it up to that and it should be ok. They have a racing circuit so I imagine that is a lot of practical experience. Im just going to have faith in the Traxxas LVC and have fun. Im still on brushed until next months' budget so I think it should be fine.

  4. #4
    Marshal ksb51rl's Avatar
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    Advice on the LVC can of worms

    They are idiots. You can tell them I said/wrote that.
    Thereís a saying that goes around here that I believe came from a rather arrogant but knowledgable member:
    ďGo to your LHS for parts. Come HERE for advice.Ē
    The best advice you can receive in this instance is to follow Danís advice. It is in his best interests to tell you how to keep his products working at their maximum performance level.
    Two of the best, highest-regarded battery vendors on this forum - SPC and SMC - recommend LVC to be set at 3.5 to 3.6 Volts per cell. The owners/operators of those companies have run THOUSANDS of batteries. How is that for practical experience? Their recommendations are not some sales fluff. Itís what you should follow. That you would feel so free to discard the vendorís instructions quite frankly leaves me incredulous.
    Last edited by ksb51rl; 04-06-2018 at 09:50 PM.
    Alt-248 on the number pad = į

  5. #5
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    Quote Originally Posted by ksb51rl View Post
    They are idiots. You can tell them I said/wrote that.
    There’s a saying that goes around here that I believe came from a rather arrogant but knowledgable member:
    “Go to your LHS for parts. Come HERE for advice.”
    The best advice you can receive in this instance is to follow Dan’s advice. It is in his best interests to tell you how to keep his products working at their maximum performance level.
    Two of the best, highest-regarded battery vendors on this forum - SPC and SMC - recommend LVC to be set at 3.5 to 3.6 Volts per cell. The owners/operators of those companies have run THOUSANDS of batteries. How is that for practical experience? Their recommendations are not some sales fluff. It’s what you should follow. That you would feel so free to discard the vendor’s instructions quite frankly leaves me incredulous.
    So then why does the Traxxas hardware cut off way lower than that? It pretty much means you HAVE to go with another manufacturer for your ESC or else you are gonna burn your batteries!

  6. #6
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    Advice on the LVC can of worms

    Also to play devils advocate, if you read alllll the CYA legalease it wouldnt be too far fetched to imagine the company would benefit from your batteries burning up faster so you would have to buy more...I dont know who Dan is, and Im not making accusations here, but its common practice for manufactures to recommend extremely cautious methods so they can void your warranty when you admit that you didnt follow that particular piece of advice.

    Im kind of upset that this truck I bought is inherently flawed and DESIGNED in a way that it would do damage to my batteries.
    Last edited by ksb51rl; 04-06-2018 at 10:50 PM.

  7. #7
    Marshal ksb51rl's Avatar
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    Iím not the person to answer that. The only Traxxas surface ESC (EVX-2) I ran for any appreciable time with LiPos did not have low voltage detection. I ran one or sometimes two Low Voltage Alarms with it, set to 3.5 or 3.6 Volts per cell. The Mamba Monsters in the ERBE originally had a 3.0 cutoff, which was eventually increased to 3.2 Volts per cell. Itís still too low. How do I know?
    Truck moves sluggishly;
    LiPo batteries heat up; and
    LiPo cell voltages diverge significantly.

    I understand you want to do what you want to do, but you donít seem to understand that some of us (me, the vendor) are just trying to help you out.
    I set the LVC on those to 3.5 or 3.6 Volts per cell too. I donít really need to because by now I can tell when the packs start dumping and performance suffers. That happens well before the 3.0 or even 3.2 mark.
    Alt-248 on the number pad = į

  8. #8
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    Quote Originally Posted by ksb51rl View Post
    I’m not the person to answer that. The only Traxxas surface ESC (EVX-2) I ran for any appreciable time with LiPos did not have low voltage detection. I ran one or sometimes two Low Voltage Alarms with it, set to 3.5 or 3.6 Volts per cell. The Mamba Monsters in the ERBE originally had a 3.0 cutoff, which was eventually increased to 3.2 Volts per cell. It’s still too low. How do I know?
    Truck moves sluggishly;
    LiPo batteries heat up; and
    LiPo cell voltages diverge significantly.

    I understand you want to do what you want to do, but you don’t seem to understand that some of us (me, the vendor) are just trying to help you out.
    I set the LVC on those to 3.5 or 3.6 Volts per cell too. I don’t really need to because by now I can tell when the packs start dumping and performance suffers. That happens well before the 3.0 or even 3.2 mark.
    Im not attacking you, Im trying to understand you. How are you setting LVC? all the research Ive done shows that that is not an option....

  9. #9
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    Can anyone more adult and reasonable explain how I am supposed to be able to adjust LVC settings?

  10. #10
    Marshal ksb51rl's Avatar
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    You cannot adjust the LVD on the current Traxxas-designed ESCs. Itís not an option.
    Alt-248 on the number pad = į

  11. #11
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    Quote Originally Posted by ksb51rl View Post
    You cannot adjust the LVD on the current Traxxas-designed ESCs. It’s not an option.
    Does that mean my only option is to buy an aftermarket ESC?

  12. #12
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    Quote Originally Posted by Rekreant View Post
    Can anyone more adult and reasonable explain how I am supposed to be able to adjust LVC settings?
    YES get one of these [IMG]
    [IMG] and set it to 3.7

  13. #13
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    Quote Originally Posted by 32SLIDEWAYS View Post
    YES get one of these [IMG]
    [IMG] and set it to 3.7
    THANK YOU. I did not know that something like this existed.

  14. #14
    RC Champion MaXXL's Avatar
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    As others have said, you are able to run your lipos to 3.3v. They will be fine. HOWEVER, you wil get much more life out of your battery if you run it down to 3.7v instead. Its something like 2x or 3x the amount of charge/discharge cycles. You'll extend the lifespan even more if you only charge them to 4.15(ish) volts.

    So while you could get away with 3.3v cutoff, you would be much better off with a 3.7v cutoff
    10 RCs and counting 😅

  15. #15
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    Quote Originally Posted by MaXXL View Post
    As others have said, you are able to run your lipos to 3.3v. They will be fine. HOWEVER, you wil get much more life out of your battery if you run it down to 3.7v instead. Its something like 2x or 3x the amount of charge/discharge cycles. You'll extend the lifespan even more if you only charge them to 4.15(ish) volts.

    So while you could get away with 3.3v cutoff, you would be much better off with a 3.7v cutoff
    The problem Im finding now is while searching amazon for lipo voltage alarms almost all of them seem to either break to easily , or are off by as much as .3 volts. Does anyone know of a reliable maker for these alarms? I searched amazon cause I am a prime member.

  16. #16
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    Nice nice

    Here is the link for MotionRC https://www.motionrc.com/collections...-voltage-alarm.
    [IMG] You MUST use Velcro too attach to something like the battery hold down or something that's available. The people that break these DONT MOUNT THEM I have one that I've been using for 5 years.
    Last edited by 32SLIDEWAYS; 04-07-2018 at 08:23 AM.

  17. #17
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    I guess you already know that voltage drops some while a pack is under load. Running with LVC at 3.0v your pack while in use is actually running below safe discharge voltage while in use under load. Resting voltage and voltage under load can vary quite a bit depending on the quality of the cells. This voltage sag is one reason you turn off LVC when using nimh. The sag in nimh is greater with nimh than with lipo and of course the more power that is drawn the greater the sag. Lipo alarms can seem as if they are off while running because while in use the voltage drops below your setting and the alarm starts to beep. Then voltage goes back up when not under load the alarm stops beeping. I have used these https://www.ebay.com/itm/X3-RC-Lipo-...EAAOSwLnBX5WvX on brushed setups without LVC without hardly any issues. If anything a lipo alarm can give quick indication of what the voltage is on your pack before you store it or go to use it.

  18. #18
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    Thanks for the advice guys. I ended up messaging SMC batteries directly about the issue and he reccomended the Venom voltage alarm. I did some searching on youtube and found someone testing it vs others and it seemed to be the most accurate when measured against a calibrated test equipment setup. Its a few more dollars than the generic ones but the accuracy makes it worth it.

    here is the link he sent me: https://www.venompower.com/products/...lipo-batteries

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