HELP! LiPo problems.

[Nmbr1GMfan]

Bone stock Traxxas Spartan I bought for my daughter, she runs NiMh batteries and LiPo. We have only run the LiPo combo twice with a pair of Venom 5000 mah 11.1 35c batts. First time after the first run one of the batteries puffed up so I took it out of service. I went today and purchased a replacement and after the first run one pack was puffed up again. both times the packs were charged at 4.6 amps and both times the boat was run full throttle for 30 seconds max, mostly half throttle. What am I doing wrong?????????
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[Chilli]

You could be running the batteries down too low. Are you running them until the boat dies out? Do you have a low voltage cutoff on the boat and is it set up for Lipo's when you run them?

[Nmbr1GMfan]

You could be running the batteries down too low. Are you running them until the boat dies out? Do you have a low voltage cutoff on the boat and is it set up for Lipo's when you run them?

I do not know the low voltage, I think the ESC has a low voltage cut off. When the boat starts to slow she brings it in, so no she never runs it till it stops but I can not confirm the ending voltage. Yes it claims to be LiPo ready. thanks for your help.

[Nmbr1GMfan]

From traxxas website: "Built-in two-stage low-voltage detection for LiPo batteries"

[Chilli]

Okay, Not familiar with your hardware but check the battery voltages if you have not put the packs on the charger. I'm curious to see where they are at. Hopefully someone who is more familiar with your boat will chime in.

[Nmbr1GMfan]

Checked with another charger that has a storage charge feature. the battery that is ok had 10.4 volts when I set it to dis-charge. The puffed pack wouldn't do anything the charger just detected low voltage so I will have to check the actual voltage with a multimeter but since the boat has a low voltage ESC and the good pack has 10.4v Im going to assume these batteries are junk and I will stay away from them.

[Mattwarner]

10.4v on the good pack is on the low side but not too bad, my LVC kicks in at 3.6v per cell which is 10.8v and is about as low as recommended but would be interested in seeing the multimeter reading as if your charger is giving a low voltage warning its probably under 9v which would explain the puffing as its been discharged too low.

[siberianhusky]

Venom are odd batteries, my experience - they either fail fairly quickly or you can't kill them no matter how much you abuse them.
I've never run them in a boat but a buddy has, by all rights those packs should have burst into flames! Yet are still alright.
My local hobby shop had some smaller packs in stock, picked some up for my plane, some are still good, some died for no reason. All in the same plane, only one I have! Positive it's not the setup as some are still working and the cheap chinese ones I also bought for it are still working.

[Nmbr1GMfan]

10.4v on the good pack is on the low side but not too bad, my LVC kicks in at 3.6v per cell which is 10.8v and is about as low as recommended but would be interested in seeing the multimeter reading as if your charger is giving a low voltage warning its probably under 9v which would explain the puffing as its been discharged too low.

This is exactly what I was looking for. My boat is obviously not going into low power mode correctly and I am discharging the batteries way to low. So it's not the fault of the Venom batts.