I used the Zippy 4200mah battery for two activation’s over the weekend and worked fine.
Left the battery connected to the radio when I packed away.
Got the battery out to charge today and connected to the Turnigy charger.
Set to LiFe Balance charge, 1.3a 13.2v (4S), pressed start and got an error.
“Cell error Voltage invalid”
Checked voltage with a multimeter and got 5.5v? Also tried with a plug volt meter display that connects via the white multi-pin and that didn’t show any voltage.
Hmmmmm, yes that doesn’t sound good. You could try setting your charger to 14.4v and dropping the charge current to 1.0a. But stay with it for a few minutes if it does decide to charge.
I fear so. If the voltages per cell falls below 3V, the battery will be damaged. A lipo pack should always be equipped with a protection circuit that interrupts the current draw in this case. Even if your transveiver was switched off, it draws power from the battery. With the known FT-817, this is a few mA and the worst case occurs in hours with a discharged Lipo.
I did the same thing to a 3S LiPO John and it never recovered. Unfortunately it doesn’t look good for your LiFePO4. I note you are trying a balanced charge. I wonder if your charger has other settings to try - if so the storage setting might get it started, but as to whether any life can be breathed into it is another matter.
It’s an obvious idea John. Just remember shipping in the UK will be an issue so best if you go ahead to arrange a face to face meeting to hand over the goods.
Minimum in-service discharge voltage for an LiFePO4 cell is 2.5v and irreparable damage starts at 2v so I don’t hold out too much hope for your battery. If left for a time the voltage will sometimes recover a bit which may allow the charger to work but if you do manage to get it charging you need to watch it very closely for swelling and heating. If you do get some charge into it you may well find the capacity is seriously reduced.
If it was my battery I wouldn’t be able to trust it and would dispose of it safely (please NOT by putting it in a bucket of salty water )
My charger has a “repair” option on it which I think restores over discharged cells to some extent, although I haven’t used it.
If it’s puffed up though it sounds like the damage is terminal.
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