What should you do if the voltages of the service battery or engine battery on your boat are reset for some reason? You may have to pay large expenses due to some minor mistakes made.
If the voltage of your batteries is 7 volts or less, your batteries are completely empty (in 12V systems) and the voltage that starts to damage the batteries if the batteries fall below 11 volts.
Although the vast majority don't know, the 12V battery level doesn't mean the batteries are full. If your battery is 12V, 50% of the battery capacity is discharged. If your batteries aren't gel, then it's time to charge.
However, if the voltage of your batteries is reset, never charge your batteries with the charger on your boat, also known as the charger. You can't fill an empty battery with this type of charger, and you're likely to burn your charger. Considering that these types of chargers are quite expensive, I wouldn't recommend taking this risk.