low voltage alarm

[skymaster]

So last week I took out my traxxas and added a low voltage alarm gadget that i had collecting dust. it's a venom one, went to do some speed runs and some bashing once i made the mistake of standing behind it on a lot fill with gravel, have u ever been stone, don't recommend it . Well the thing never went off. so my question is which cell does it set it off. I was using a 2cell lipo, one cell go to 3.5 and it did not set it off. the alarm is set to go off at 3.5. so an unbalanced lipo might not set it off ???

 

[Piotrsko]

It measures total voltage and decides a cutoff based on original voltage. One bad cell will lower pack voltage significantly. It will also rebound rapidly when the high current draw reduces. So: until the rest of the pack goes to about 70% voltage level, it isn't enough to trigger a low alarm and you won't get full advertised mah

 

[skymaster]

so if the lipo is not balanced let's say my 2cell 4000mAh 50c is on one cell at 70% and the 2nd cell is at 3.5% it will not go off until the first cell is also at 3.5% meaning my lipo is done for. is this correct

 

[Piotrsko]

Didn't say it's done for unless the bad cell goes below say 2.5v. (chemistry related and varied). however your recieve side probably will glitch madly and it will kill the low cell