This is UNBELIEVABLE!

[km1125]

The difference between lead-acid and AGM is so slight, pretty much any "good" charger would work on either. You might just want to check what kind of charger it is anyways, so you have that info handy.

If they're NOT labelled, then now would be a GREAT time to figure out which is which and label them appropriately. You can (and should) also make sure that they are all getting a feed from the charger.

Is that a gas or diesel boat? That would make a big difference in the batteries.

[Cooler]

Paulr - I have been using Interstate batteries for years, and I am very happy with them. Starter batteries are 24XHD, as they are 1000 MCA with plenty of initial punch. House battery is 31XM as this is a deep cycle with long discharge time, and quick recovery period. Not sure what your generator needs but would imagine you can use the standard 24 model, not necessarily the XHD. Not sure what you have for chargers, but you may want to make sure they are 10 amp per battery output. Interstate is a little pricier than a low cost battery, but way better value IMHO. I am assuming you have gas engines. er

[paulr]

I took possession of a 20021 396 in November 2022.
The survey showed 3 bad lead acid batteries.
I replaced the lead acid batteries and have not had any trouble at all.
I check the water once per month and have not have to add any yet.
Very happy with the old technology.