Noob Battery Mistake!

Hi Guys, I’m running two 3s 11.1v 5000mah batteries in serial, and for the first part I was charging each one individually, because I don’t yet have a 2 x 3s > 6s balance lead adapter, then I got lazy and just started charging it in series with no balance leads! Now both my middle sells are at 0.00v and they won’t charge up! Is there anything I can do or are they a gonner?

Thanks for your help. I think I’ve learnt a valuable lesson here :disappointed:

0.00V seems not right. You are sure your measurements are correct? How did you measure them?


can you measure with a multimeter? When you charged them was your total voltage correct? I mean if you charged a 6S battery to 25.2V and now the cells are 2.91 0 and 3.67 there must be something weird going on.

Not without dismantling the battery, which at this early stage I don’t really want to do. I may do though because I may dismantle both my packs and salvage what I do have left with some others and make a bigger pack.

Oh, did I mention that BOTH 3s 11.1v packs that I’m using are like this? Both middle cells are at 0v :frowning:

I mean if you charged a 6S battery to 25.2V and now the cells are 2.91 0 and 3.67 there must be something weird going on.

You’re right, I’m sure when I took them off charge before they were at the correct voltage! Something fishy’s going on here. Do you think maybe (and it would be a massive coincidence) that both middle cell balance leads have become unsoldered?

how can you hook them up but not measure with a multimeter? You just need to measure the pins of the balance wires.

Oh! I see, sorry, I misunderstood. I’ll give that a go…

there´s definitely something wrong with this. Both cells at the same lvl is like winning a lottery (i mean by chances - don´t get me wrong here :smiley: ) hope you didn´t won the lottery :smiley:

1 Like

I also wonder how the third cell can be detected as 3.67 when its ground level (the second cell) is desoldered. You should measure total pack voltage with a multimeter and the single cell voltages. If they add up to the total then your second cell is probably toast - otherwise there is something wrong with your balance wires.

OK, this is weird, I just checked with a multi-meter, and all three cells are showing 4.08v (as I just fully charged one pack)!

You think my iMAX is playing up?

Check if your balance cable is inserted correctly and fully in the charger. You might just have had a loose connection.

1 Like

these numbers sounds more realistic to me. yep check you balance cables and the connection to your imax

Yep, all fully in there… I just checked the pack at the XT60 connector and it’s coming up at 12.22v which is right…right?

As long as they are 4.08V they should be perfectly fine. 12.2V for a 3S pack is also fine. I am just not sure why your charger is showing those weird values. maybe check the charger’s balancer pins for corrosion or dust or something.

I think my iMAX might be up the swanney as it’s getting VERY hot! Which it didn’t do when I first got it…

Does anyone else’s get hot when charging 3s?

Temperature should depend on charge current. at something moderate (like 2A) it should not get too hot. You might have shorted something. –> I’d get a new (quality) charger. Hobbyking’s Reaktor series is supposed to be good for example.

OK it’s definitely that my charger (iMAX B6AC) is faulty, the other pack just came off charge and that too is at 12.4v, even though the balance display was as above! I just checked each cell via the balance lead and they’re all around 4.08v.

OK, so It looks like I can still used the charger, if I don’t mind it getting a little hot, and don’t rely on the display!! :disappointed:

Not good, it’s not very old at all. Less than a month!

Thanks all for your help, at least it’s not my batteries! Phew!!! :flushed:

Be careful with a broken charger. We don’t know what else it will do wrong (overvoltage for example). Lipos are dangerous and can burn your house down.

Good point. I won’t ever leave it charging unattended. If I can get more life out of it before blowing up one or more of the batteries, then all’s good. However, come payday I’ll order another charger. Maybe that HobbyKing one…:+1: