unbalanced cells on P2V+smart battery
- Thread starter kjack42088
- Start date
Whoa thats way out of whack! Dont fly with this battery. Looks like its only new. Bring it back to where you bought it (hopefully a dealer) and bring your laptop to show them. Cell 2 looks like its gone. If it was an older battery I'd tell you to deplete the battery by tying it down with the props on and spinning until the battery dies and then fully recharge and check the voltages then but in this case because it only has 4 flights I wouldnt trust it and get it replaced. Again dont fly with this battery.
well it was my own fault i took a spill and landed it in a little water on a lake... doubt they would give me a new battery. i have more batteries coming in i was just wondering if i could save this one? when i power up my pv2+ i can let the motors idle and after a few min the battery thinks its dead and shuts the craft down so i don't know that i could use that technique to drain it. what if i used a light of some sort?
Ahh the plot thickens, haha maybe you should have mentioned the water incident. Tie it down or weigh it down and give her throttle to drain the battery and recharge, then check the levels but now I'd be thinking its for the bin. I'd never trust that battery again myself. You are lucky it was fresh water rather than salt water and its just a battery gone. Follow my advice but even if the cell reads good after that I'd still dump it.
yeah i originally typed a huge story and somehow it got erased as i was submitting it!!! but i can't even use the tie down method... i think its reading that one cell is to low and shutting off because of it, it will power on, idle for like 4-5 min then die. and I've done that about 5 times now. i just rigged up a 12v light bulb and some wire to the battery to try and drain it all the way. maybe the battery isn't smart enough to shut of a direct wired light bulb lol.
Haha I always like ingenious thinking, light bulb, nice idea. But for me I'd still dump it and count your blessings that you still have your phantom. Even with a new battery just keep an eye on it and the voltages just in case there are internal battery conact issues
yeah probably a good idea. if i can get this one discharged and recharged/balanced ill cycle it through a few times at idle and just use it for low flights over land lol.
if i decide not to use it and it won't work ill dismantle it and try to learn a bit from it and post some guts pics of it for everyone here
The cell voltages displayed are completely bogus. (However, the overall pack voltage looks sane)
5.8 volts from a LiPo cell is impossible. You can't get a cell to this voltage - it'll explode/burninate long before that. Similarly, if a cell actually did drop below the undervoltage protection (usually somewhere in the 2.7-3.0 volt range), the whole pack would get isolated.
Who knows what the cell voltages really are, but if the BMS is reporting bogosity like that, I wouldn't fly that battery again. There's a good chance that the cells are in reality reasonably balanced now but the same thing causing the cell voltages to get misreported may cause the balance to go WAY out of wack in only 1-2 charge cycles.
5.8 volts from a LiPo cell is impossible. You can't get a cell to this voltage - it'll explode/burninate long before that. Similarly, if a cell actually did drop below the undervoltage protection (usually somewhere in the 2.7-3.0 volt range), the whole pack would get isolated.
Who knows what the cell voltages really are, but if the BMS is reporting bogosity like that, I wouldn't fly that battery again. There's a good chance that the cells are in reality reasonably balanced now but the same thing causing the cell voltages to get misreported may cause the balance to go WAY out of wack in only 1-2 charge cycles.
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