Dead Sony Batt

Anyone run into this before?

One of my Sony L Batts, NP-F770 batts has died. When i put it in camera there is nothing. When i pop it into the charger it doesn't charge and I get a flashing "warning" on the charger LCD.

Any ideas? I guess it is dead and i have to buy a new one?

Probably dead if it doesn't charge.

Maybe the passivating layer problem some can get if you leave them sitting around for abit.

I have brought one back to life abit using this method with a resistor.

Go and have a read here.

http://www.bealecorner.com/trv900/battery/lithium.html