12 volt battery

[Steve]

Currently installed on boat are two group 24 starting batteries. Both need replacing. Should I go with two of the same, two deep cycle, or one of each? The deep cycle to be house battery. The h30 involved has a battery switch, off 1 both 2.

 

[Bob Zolczer]

Mix 'em up

I replaced the batteries on my boat last year. I got a Grp 24 for a starting battery, but went with a Grp 31 for the house battery (takes electrical loads while at anchor). The additional capacity of the grp 31 made more sense for the house battery, especially when we use the 12v tv/vcr at anchor on rainy days, Logically, it makes no difference which is "1" or "2", as long as you switch it over to the appropriate number battery when using house loads.The charger or alternator will charge both batteries regardless of the switch position on my 29.5,

 

[Paul Akers]

Rotate them

I have 1 starting and 3 house batteries. They are all Group 24, deep cycle with starting capabilities. I remove them and label them for winter storage and in the spring rotate them. I take one of the house batteries and make it the starting battery and move the former starting battery to the house bank.

 

[Eric Lorgus]

It depends on how much cranking you do

Steve, I'm no expert, but I do know that cranking batteries and deep cycle batteries have different designs. Cranking batteries can't handle more than a few deep discharges - they're designed to deliver big bursts of amps for short periods. Deep cycle batteries are designed to provide steady flow of amps over longer periods. I have one of each on my boat (87H28.5), and have sometimes used the deep cycle to start the diesel. But my diesel always starts right away during warm weather, so I've never really taxed the deep cycle very much to start it. Some diesels take more cranking to get them started. If yours is one of them, you may want to have one cranking battery.