I have a minn kota onboard battery charger. I don't know which model it is. It is a 3 battery charger rated at 30 amps total with 10 amps per connection. When checking the voltage output its at 13.2 volts. Is this normal? It seems low to me. I was checking this toward the end of the charging cycle. Now I am wondering if the charger change its voltage output as it goes through its charging process. This all started from having a battery that seemed to be weak. So, I took the battery out and put it on a different charger. Its voltage output was over 15 volts. It took about 2 hours to fully charge the battery. The inboard charger indicated that the battery was fully charged.