If the battery really is frozen, you shouldn't put a charger on it. You should thaw it first. I had one freeze recently (vehicle wasn't driven for a long time), so I brought it into my basement, and the next evening, put a charger on it. It tested good after the charge (load test and conductance test were both good). Putting a charge to a frozen battery will probably ruin it, and there is a chance it could explode.