WHOA! battery did something REAL strange!

[glassdoctor]

Might be a simple as a bad solder connection that "fixed" itself with the handling of it...

but more likely it's a bad cell (internal short that was blocking voltage) that woke up when you hooked up the charger, thus allowing the pack voltage to flow again.

I've seen old packs act a bit like this.. they have cells that drop voltage really low, but the voltage goes real high when charged... I can't explain why... only guess.

[jhautz]

Not unusual at all. I had some old GP3300 sitting in a box for the past year and decided I wanted to use them for a rotostart. They read virtually dead like yours when I tested them, but when hooked to a charger (I didnt go 6A right out of the box like you) they peaked very quickly only taking a couple hundered mah of capacity. But you can revive them....

You are best off if the pack has been sitting for a long time is to cycle it 3-4 times with lower than normal currents. Just completely discharge it down to .8 volts/cell and the slowly (like .25amps) charge it again untill it peaks. Then let it rest a bit to cool down and then do the same thing a few more times. The first few cycles wont take long as the capacity will be drastically reduced form sitting for so long, but the last couple you should be getting close to theier normal capacity again and they will take longer. After that you can go back to your normal high amp charging as you always did. You will get most of the pack capacity back by doing this, but an older pack like that usually looses some puch and capacity just from age. They will probably be good starter box or roto start packs now though.


EDIT: Damn brian... you responed while I was typing