I was in a hurry during lunch hour today and I wanted to top up the battery in my snowmobile for the coming winter season. I connected everything, powered up the charger on a 2 amp charge setting and made my way to work.

I got home this evening and checked the status gauge on the charger. It indicated that it was still charging which seemed a little long. I proceeded to disconnect the charger only to realize that I had the terminals reversed. The battery was quite warm and I was only able to hold onto it for a few seconds at a time. I was a little worried and disconnected it from the machine and placed it in the middle of the backyard. I connected a 12volt light and it lit right up. After about 5 minutes it started getting dimmer. I then took my multimeter and tested the voltage (ensuring Red on Red and Black on Black!). The voltage read -3.5 volts. Yikes. I let the light completely drain the battery for a few hours. The battery stayed warm for a long time, even though the temperature was -4 Celsius outside.

Right now the battery reads a voltage of -2 and has been sitting in my storage room for a half hour or so. Should I try charging it properly? Should I find a small 12 volt light to hook up to it to drain every last bit of power out of it first? Should I give up and buy a new battery?

The battery is identical to motorcycle batteries as well as many other small vehicles.

Thanks!
Rene