Basic battery question

[Aloha Friday]

My marina accidentally forgot to turn off my battery switch before putting the boat back into dry storage. It was set to Battery 1 which would not start. So, I set it to Battery 2 and all was well today. Now to my question - Is recharging a boat battery any different than an automotive battery? Would either a trickle charge or running the battery switch recharge my dead battery?

 

[dpvandy01]

It depends alot on what type of battery. If the dead one is a Cranking Bat and it was fully discharged it's time for last rights.. Cranking batteries don't take kindly to full discharges. Deep cycle on the other hand should charge back fine. I think it would take a good long run to recharge while underway but a trickle charger would do nicely

 

[wingless]

Batteries should be maintained fully charged to maximize life.

When batteries are permitted to remain below 50% state of charge they suffer permanent damage called sulfation. Modern chargers can exercise the battery to improve the damage, but they still lose capacity.

 

[fc3]

I hate battery questions but here are my simple rules.

Don't deeply discharge flooded cell batteries. If you do, it's probably ok once or twice but not more than that. No special charging is required.

Do check the water level in flooded cell batteries regularly and add distilled water to bring the electrolyte level to the full mark.

Replace the battery when it show signs of weakness.

If you are the type who does not like to do battery maintenance, does not do maintenance, or otherwise ignores the batteries, prepare to replace flooded cell batteries often or buy AGMs.

If you switch to AGM batteries, you must use all AGM batteries that are on the same circuit or charger. The charger must also support AGM charging requirements and if there is a special setting for AGM, it must be so set.

I am not hard on my batteries. We use the genny if we're going to be out much, so the batteries never discharge much. I don't mind adding water to them once in a while, so I use cheaper flooded group 27s. It would be many years before AGMs reached a break-even based on my use. Your mileage may vary.

Best regards,
Frank