Results 1 to 18 of 18
  1. #1
    RC poster
    Join Date
    Dec 2012
    Posts
    5

    Low voltage cut off?

    I have just got the 1/10 summit, and it has 2 5000mah lipo with it. I have a balance charger and when the low voltage cutoff kicks in the charger is telling me i still have about 3.99 volts available. from the asking around at the hobby shops and from a few other RC drivers, my cut off shouldn't be till about 3.7 volts. I'm new to the hobby and am wondering if there is anything i can change on the LVC or if there may be a problem with my batteries. I have been told that with more use you will get more drive time out of them but it being new and only getting 10-15 min per charge its kind of discouraging. the hobby shop said i should turn off the LVC and add alarms has anyone else had these kind of problems and if so what did you do to fix it thanks.

  2. #2
    RC Racer
    Join Date
    Jan 2013
    Posts
    190
    I asked the same basic question, stemming from the same observation with my Traxxas 7600 mah 2S batteries in my Summit. The way I understand it from the replies I got, the voltage detection watches for any cell that may break the LVD setting, and when you pull hard your voltage momentarily sinks. As the battery average voltage drops, this under-load voltage is also dipping lower. So, what you and I see with the removed Barry on the charging bench is higher than your ESC was seeing when you were hammering throttle at various loads. The LVD system protects your packs from dipping momentarily into a dangerous voltage level.

    The other thing is that you, like myself, may be in cold weather, and your Lipo packs will not deliver the same performance as they will once the weather comes back into sorting and summer temps. I'm normally above storage voltage when I remove the packs and check them after I've hit the LVD 50% power program in the ESC and shut off the truck.

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

  3. #3
    RC poster
    Join Date
    Dec 2012
    Posts
    5
    so basically what your saying is there is nothing wrong with either my batteries or my LVC, its the cold and how i drive? is there anything i can do to correct the issue? i would like to be able to drive for longer then 10 minutes.
    thank you very much for your response.

  4. #4
    RC Racer
    Join Date
    Jan 2013
    Posts
    190
    So far as I understand it, until the temps come up, we are all dealing with the same thing.

    As a work around, you can order the LVD alarms from one of many web sites, you plug them into the balance plug and they emit an audible siren if your cells are below the set voltage. You would then disable the LVD on your Traxxas ESC, and go only by the audible siren. That way, if your getting an intermittent alert, you can keep going until it becomes more constant. That will allow you to filter out the short dips in voltage as you should hear the alarm for a few seconds and then it should go away.

    Again, this is what I understand from what was told to me, I am dealing with it using the ESC LVD just as you are for now.

    On a side note, please charge your packs tomorrow and note what the charger says your individual cells are reading and then hit the wires on the balance port plug with your volt meter and see what the cells actually are at.

    There stands a chance that you are not actually full charged when your charger thinks that you are. In other words, your charger ends the charge cycle at what it claims is 4.2 volts per cell. You unplug the battery and hit it with the volt meter on the balance plug and you see a true 4.08 volts per cell...... or something that is lower than what you thought you had, lower than 4.2 volts per. So then you put that not fully charged pack(s) in your RC and you hit the true LVD in short order.

    You should really investigate this with this idea in mind. I have the Duratrax Onyx 245 and it lies a bit on voltage. My "full charged" packs are around 8.25 volts.

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

  5. #5
    RC Racer
    Join Date
    Jan 2013
    Posts
    190
    Hey, just to help you out, your balance port has three wires.

    If you look at the plug, you'll notice that one side has three exposed strips of the pins that you can easily and gently get your volt meter probes to make contact with. Don't try to jam the probes into the plug or try to poke into the insulation.

    Put your volt meter probes on the center plug pin and the left plug pin to read one cell, and the center plug pin and the right pin to read the second cell. To read total volts in the pack, use outer pin to outer pin on the plug.

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

  6. #6
    RC poster
    Join Date
    Dec 2012
    Posts
    5
    Thank you very much for the info. I have the v6ac balance charger. It is giving me a 4.20 per cell reading. My meter is at work so I will look into that on Monday. I have ordered the audible alarms tonight on eBay so they should be here in a couple of weeks. I also have the 1/16 summit but it uses the NiMh and I haven't had any power problems with it but the truck itself is now here's near as strong( lots of repairs ). I will look into the proper charging when I have my meter back and once again I can't thank you enough for all the info.

  7. #7
    RC Racer
    Join Date
    Jan 2013
    Posts
    190
    Just checked my Onyx 245. 4.12 volts per cell at full charge with my digital multimeter. So I'm giving up a bit compared to the chargers displayed 4.2 volts per cell.

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

  8. #8
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
    Join Date
    Oct 2009
    Location
    Alma, MI
    Posts
    11,969
    NiMh self heats so they are better to use in snow... if they stayed cold like LiPo they would die early too.

    Keep in mind that voltage dipping damages LiPo's just as much as running them too low so don't set the alarm lower just to get more run time in cold weather.
    Whatever it is I just said... I could be wrong.

  9. #9
    RC poster
    Join Date
    Dec 2012
    Posts
    5
    Thanks for all the responses. My summit came with lipos so that's all I have right now. The summit was pricey so I'm waiting before I buy anymore batteries but I will get my meter and look into that voltage shortage tho. Thanks

  10. #10
    RC Qualifier
    Join Date
    Oct 2012
    Posts
    540
    So a Lipo won't last long in the snow and NiMH will?
    Dirt Slingerz Racing
    Slash VXL - Summit

  11. #11
    RC Champion
    Join Date
    Jan 2012
    Location
    Toronto
    Posts
    2,317
    Lipos - like most batteries - have an optimum discharge temperature. They will perform much better at 100F than if they were 40F or 140F. =)

  12. #12
    RC Qualifier
    Join Date
    Feb 2012
    Location
    Montreal, Canada
    Posts
    519
    I use my Lipo through the snow at -15c it works great until the LVC hits. My NIMH itself dies earlier than expected and both batteries came from a warm wrap which I always do everytime I play with my Summit. I don't get it why you said that Lipo's doesn't perform well on cold weather???

  13. #13
    RC Racer
    Join Date
    Jan 2013
    Posts
    190
    My ni-mh packs don't perform the same time span in sub freezing weather as they do in moderate temps. The Lipo, even in 15 degree weather way outlast and out perform the ni-mh.

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

  14. #14
    RC Champion
    Join Date
    Nov 2012
    Posts
    1,150
    I would not trust that charger. I started out with one of those and it killed 8 of my nimh batteries in less than a month. Their support also sucks i have sent 4 emails and gotten 1 response back because they thought i wanted to buy a charger..

  15. #15
    RC Qualifier
    Join Date
    Oct 2012
    Posts
    540
    So do I have to make a lipo water proof if I am going to go snow crawling with it?
    Dirt Slingerz Racing
    Slash VXL - Summit

  16. #16
    RC Turnbuckle Jr. Jimmie Neutron's Avatar
    Join Date
    Oct 2009
    Location
    Alma, MI
    Posts
    11,969
    Whatever it is I just said... I could be wrong.

  17. #17
    RC Competitor
    Join Date
    Dec 2012
    Posts
    61
    Quote Originally Posted by Jacob Chandler View Post
    So do I have to make a lipo water proof if I am going to go snow crawling with it?
    i've run lipos through water and snpw without problems but stay away from salt water it will kill them

  18. #18
    RC Qualifier
    Join Date
    Oct 2012
    Posts
    540
    OK. I am going to be running it up at my winter camp so I will try and avoid the salt they put down on the sidewalks. First time I ran my Summit on ice, it had salt on it and I ended up rusting my CJ Joints on my half shafts.
    Dirt Slingerz Racing
    Slash VXL - Summit

Posting Permissions

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