[Hooters Driver]

I have been using both Li-Ions and Li-Polys for several months. About 1 month ago I ruined a Li-Ion pack. From that experience I think I figured out what is happening to cause Lithium batteries to blow up while being charged. Here is what happened in my situation:

After running my car I put it away and forgot to unplug the battery pack. When I noticed the pack was still plugged in two days later I checked the voltage and it showed to be less than 1 volt (this was a 2 cell 7.2 volt pack).

Since I know Lithium batteries are not supposed to be discharged below 3 volts I figured the pack was ruined but I decided to see if it would take a charge anyway. I plugged it into my charger and monitored the voltage of each cell closely. One cell came back up above 3 volts without any problems. The other cell, however, would not take a charge and began heating up almost immediately. I unplugged the charger, disassembled the battery pack and then tried charging each cell individually. The first cell took a full charge without any problems. Once again the second cell would not take a charge. No matter what amperage setting I used the battery would almost immediately begin heating up. I threw that cell away and wrote it off as a lesson learned.

What I think happens to other people is they drain their batteries below 3 volts then plug them into a charger and walk away without monitoring what the cells are doing.

Many people don't realize the damage they cause to the batteries when they allow the voltage to drop below 3 volts. Then when something blows up while the batteries are charging they blame it the charger or on the batteries being defective.