completely dead battery after no use?

[figueroa4]

I have a 560 and I was using it pretty steady a month or two ago. I could get about an hour or so out of it using the battery. Well it hasn't been used since then. I put it to charge yesterday and went to use it and nothing has happened, it's still completely dead. The charging light doesn't even come on when it's plugged up. (The light does work however because it flashes on during start up.) Is it gone or is there something I can do? I have the adapter so the pc isn't a total loss, but I'd love to have the battery back.

[Robbyrobot]

I don't know what others have experienced, but I had this happen to a TP 760EL battery (same kind as in the 765) when I didn't use the computer for several months. The battery was previously used, but apparently OK. After the inactivity period, it was dead and couldn't be charged in either the 760EL or a 765D/L. This is a lithium ion battery, incidently.

I've begun removing the batteries from the computers if I intend to store the latter for more than a few days, just in case there's a drain through the connections. Don't know if that will help, but I assume it won't hurt.

[joester]

Here's what I think is going on...

The batteries have failsafe circuitry to protect them, and the laptop. Power is cut if voltage rises above predetermined value, and if it drops below a predetermined value. Unfortunatley, the circuitry will not allow recharging to usable levels.
You can open the battery and individually recharge the cells to the expected 3.6 volts, and the battery may be OK. It depends on the design of the circuit.
Now, I cannot express enough the dangers of opening up a lithium ion battery and messing around. These things can and will catch fire if not handled correctly. Too big a charge or discharge rate will overheat the cells, and you got problems.

I have had some success opening up batteries and trickle charging them @300mah. You will need to charge the cell pairs to all read the same voltage.

DO NOT SOLDER TO THE CELL ITSELF. BIG NO-NO, AND YOU'RE MESSING WITH FIRE. LITERALLY. A FIRE YOU CANNOT PUT OUT. IT NEEDS TO BURN ITSELF OUT.
I personally have not experienced this, but have read enough to know that it can happen.

Joe