More bigger better batteries again!

[Joesaila]

Don't know why I feel apologetic, but I did a search, spoke w my 'marine electrician' and still am not sure what I want. I would like to put in a small inverter/charger [xantrex 1000]that will be used primarily for a house bank. I plan on just having 2 DC 31s on board. One for starting and one for night lights, computer or t.v. or some other small appliance. I have a linc 1000 monitor. While I know this may not be the best system does this even sound practical...I do like the idea of being able to charge my batts from a dock if on a slip...My boats a 30' Morgan OI. Not sure if I should scrap it or re think it. What would you suggest? Thanks!

[hellosailor]

Practical? Well, what standards are you going by?

If you are using one battery as a dedicated starting battery, you are probably better off getting an inexpensive Group24 or Group27 SLI (starting) battery. And then using a more expensive Group31 deep cycle (or larger) for the house battery or battery bank.

A Group31 is roughly a 100AH battery, that gives you 50AH of capacity for normal use to the 50% discharge point. A 1000 watt inverter/charger can pull more than that in one hour--so it is a bit of a mismatch. A charger rated for 25 amps would provide all the power that battery could take for a recharge, and if you wanted to charge two batteries at once (while they are isolated) you'd need a charger designed to do that. Two batteries, of different kinds or the same kind but different charge states, work best with a charger that senses the voltage in each one separately, andcharges each one separately--as appropriate.

[Joesaila]

Oy! Scratch that idea!