16v battery
Make sure if it is a dry cell battery that you don't use a wet style charger. I fried a turbo start this way. The chargers have adjustment to compensate for this and since doing this, I have had no problems from over charging the battery. I know that you said you thought that you had found the problem. I just wanted to post this up for anyone else that might read this thread. This was a problem that I brought on myself and was an expensive learning process. Maybe this will save someone else that expense.
Good Luck and Race Safe
Hancock Racing