Do you guys leave your 3 bank charger plugged in all the time. I always did on my other boats without an issue but this one is boiling the water out in no time if left on. I might have ruined my batteries.

If it's boiling the water out, the battery or the charger is bad. Possibly both now if it was the charger that was bad first and caused the problem.

A bad battery causes it because the charger is trying to take it to a full charge level, if the battery won't charge to full capacity, it will start overheating and the charger will start charging it even harder because as it heats, the internal resistance decrease. The other thing that happens with a bad battery, it may reach a level that lets the charger stop charging, but will not hold that level, sometimes only several hours, and the charger comes back on at a set level of discharge, and some drop into a float mode that maintains a low set level of voltage on the battery (usually 13.2 to 13.6 volts, depending on the type battery).

There are some checks you need to do with a good DVM with a current function to determine if the charger is the goes back into the charge mode, or increases the float level, depending on the type charger. Regrettably, you may have to get new batteries before you can check the charger because if the batteries are bad, the charger is going to keep on trucking, trying to charge them and there would be no way to tell if it's working properly or not.

One of the biggest causes of this when running batteries in series for 24 and 36 volt TMs and only swapping out one battery if one goes bad. If the batteries are not of the same make type and age, one will have a different internal resistance than the other. The one with the lesser internal resistance is handling more of the load than the other, and starts to fry itself. This is usually the newer of the two batteries.

If it's boiling the water out, the battery or the charger is bad. Possibly both now if it was the charger that was bad first and caused the problem.

A bad battery causes it because the charger is trying to take it to a full charge level, if the battery won't charge to full capacity, it will start overheating and the charger will start charging it even harder because as it heats, the internal resistance decrease. The other thing that happens with a bad battery, it may reach a level that lets the charger stop charging, but will not hold that level, sometimes only several hours, and the charger back on at a set level of discharge and some drop into a float mode that maintains a low set level of voltage on the battery (usually 13.2 to 13.6 volts, depending on the type battery).

There are some checks you need to do with a good DVM with a current function to determine if the charger is the cgoes back into the charge mode, or increases the float level, depending on the type charger. Some cut off and come back on at a set level of discharge, some go into a float mode that maintains a low charge level all the time, (approx. 13.2-13.6 VDC, depending the type battery). Regrettably, you may have to get new batteries before you can check the charger because if the batteries are bad, the charger is going to keep on trucking, trying to charge them and there would be no way to tell if it's working properly or not.

One of the biggest causes of this when running batteries in series for 24 and 36 volt TMs and only swapping out one battery if one goes bad. If the batteries are not of the same make type and age, one will have a different internal resistance than the other. The one with the lesser internal resistance is handling more of the load than the other, and starts to fry itself. This is usually the newer of the two batteries.

Thanks. I appreciate your answer even if it's not what I wanted to hear. lol I guess it's time for some new batteries.