Battery packs ruined?

I have 4 6s packs that I accidently left connected
to the controller. Now they don't even turn on
my powerlog battery checker.
Are these cells toast? I know it's dangerous to charge cells
that have dropped below a certain voltage.
Should I dispose of these ASAP?

Thanks in advance
David

Get a multimeter out and measure the voltage manually going off the balance lead pins. They are most likely far under ~2.5v/cell. If they've been sitting like that for a while, they either completely toast or will have a drastically reduced lifespan.

the controller is a very low rate drain, there is a chance they survived but take it outdoors if you attempt a revival !.

I have 4 6s turnigy lipo packs that I accidently left connected
to the controller. Now they don't even turn on
my powerlog battery checker.
Are these cells toast? I know it's dangerous to charge cells
that have dropped below a certain voltage.
Should I dispose of these ASAP?

Thanks in advance

Happy thanksgiving
David

If you can check the voltages with something else I would try that first, but it sounds like they are toast.

If you have iCharger or Cell-Log or maybe use voltage meter check your pack volt. If 6S's voltage showing minimum 16.2v or higher then your pack can save by just charge it bring it up to 3.8-3.85v (22.8-23.1v) as storage state.


Happy Thanksgiving

I would call em toast. They've been discharged below 2.7v now. If they puffed much, they are goners for sure.

However, they might revive if you can get some slow current into them with a dumb charger of some kind. Maybe a car trickle charger hooked to 3 cells at a time, or a cell phone charger one cell at a time.

BUT, those will never ever ever be a safe battery again. You better have a way of getting em off the bike really fast if you try to use them after recharging them. Don't trust em on an indoor charge ever again!

You might get away with it for awhile, but I'd call em junk. It's a pity, I felt the same way when I did the same thing to my trusty ol ping pack. After 3 1/2 years of use, it died because I killed it.

Sounds like toast to me, sorry to here that. The only solution I could come up with was an automatic battery disconnect when low voltage cutoff is detected. I didn't want to remember to turn off things. Draining a battery after a long ride is even more probable since there is very little capacity left, so any standby current can easily drain the packs to zero.

It's toasted.
I juste did the same thing last week: I forget the pack on the bike for 3 days, then each 6S pack was at 2 or 3v.
I tryed to slowly charge them, but after a few hours they took fire!!

Probably...but not harm in trying to revive them if you can charge them in a safe place.

I had a very dead cell..it was from a new pack from Turnigy hard case packs...It showed near on 0 volts.

My initial charging of it..outdoors was done using a Digital multi meter..the sort that measures continuity / resistance.
These meters measure resistanc by passing a small current through the device under test..at a low voltage..2 or 3 volts..depends on the meter.

So I just connected up a meter to the cell...positive test lead to positive battery terminal...via another DVM in current range to see what current flowed.

I left it like that over night with probably less than 100 mA flowing..by the next morning current flow had stopped, and the cell was up to 2.xyz volts.

From there I transfered it to the iCharge set to again a really low current..0.1C charge rate or less..and again left it to slowly charge..it came up and revived..with no puffing.

The cycled it at 1C three or four times..it is now a working cell..not one I would put in anything of value..just to be safe...but it sits on my steel workbench with the other duff cells that I have revived for when ever I need a few test cells for ...well anything.

Totally pointless waste of time really..but did it just to see if it could be done.

So if you are prepared to take your time and as long as the cells have not puffed you may be able to get away with it..but do it outdoors or somewhere safe

I'm not so sure about Lipo, but with other lithium batteries if they are slowly drained to zero, they may have some chance of recovery. The trick is to charge them at a very low current until they get up into the healthy voltage range. If you just slam them with full charge current, they will most likely go pyro. If any cells were reverse charged during the discharge process, they will be toast.

Yep, that is pretty much what I did via charging with a DVM set on continuity

Somewhere there's a recommended charge rate for flat cells. I think it's around .005C until they get up to 3v or so. I've done it with a bunch of LiCo 18650 cells that sat around for years and were zero volts. All of them recovered to what I presume was their capacity prior to being left for dead. I think 10mA would generally be pretty safe.

Just don't go thiniking you can trust those revived cells to be charged inside anymore. In my opinion.

Have a way to remove them from the bike fast too, when you are riding.

Or put them in a pretty basket and go for a ride with a friend, maybe golden gate park.

I know how you feel. I just had the same thing happened on my 12S2P lipo setup. I"m so upset right now.
I saw this on youtube http://youtu.be/DrpRn2Os-fA. Has anybody tried to recover a dead lipo battery using this described method.
I'm too scared to try it and will probably dispose the batteries properly. $240 down the drain . Looks like I have to wait until after Xmas to get some new batteries.

That is rather like throwing away dollar bills because they are a bit damaged...at least try to save them.

Do it outside/ in a bag/metal box etc and do it very slowly, either a cell at a time, or pack at a time with cell log or similar connected to balance tap to monitor each cell voltage. 001C - 0.05C...anything really low a few milli amps

I had a cell go down to 0.943V under its own self discharge (5800mah turnigy 25-35C). It had always been a little weak from new as on the first charge it was hard to get it to balance with the other cells although after a few cycles it was ok although it did have the problem of discharging itself.

From storage voltage of 3.85 it took about 6 months for it to reach 0.943V. I very gently brought it back above 3V and then charged it a 1A to full and it is behaving fine. It has had multiple discharges at an average of 3C since the event.

leeleefocus,
If you don't mind me asking, how did you charge your pack? I have 6S 5000mah batteries and I was not able to charge or discharge on my hyperion 1420i charger. It did not see the full 6 cell when it was doing it's check so it would not allow me to charge. I only read as a single cell.

Not quite sure what you mean

visuthdy said:

. It did not see the full 6 cell when it was doing it's check so it would not allow me to charge.

Click to expand...

If it did not see the full 6 cells? How many did it see? Do you have the balance cable connected properly? Is one of the balance leads broken

visuthdy said:

l
I only read as a single cell.

Click to expand...

This second comment makes me think you do not have the balance lead connected

Get a voltmeter with small probes, and carefully, measure the voltage between each pair of wires on the balance plug. Obviously, don't short the probes together while doing this
Easiest way is to stick the balance plug down to a table with 'BluTack' or tape to keep it from moving around

First scenario
If you find one cell is way out of balance, that is your problem

You will need to charge that single cell back up to a reasonable voltage first. You will need to male up a lead to do this, then set the charger up for a single cell, and charge it very slowlh as detailed in previous posts


Second secenarip
You find similar voltages between all adjacent pairs of wires, but overall pack voltage is low and all cells are down below ..,umm. 2. Maybe 2.5 volts, then you may have to do a very slow non balance charge first
Select a non balance mode on your charger, and a low charge rate. Set as low as you can 0.1 amps or sonif it will go that low. If it still will not charge like that because the pack is really in a low state, then maybe start by tricking the charger to expect a lower voltage, set it to expect a 5 cell pack voltage. If you are not award of the dangers of doing this by now, then re read this ahd the other LiPo newbie threads