Oldlaxer1

John,
My engine start battery is a Gp24, located outboard of the engine. My house bank is currently 2 of Gp31 (was 2 of Gp 27), located aft of the companionway ladder - one fwd of the post, one aft (short run up to the house panel). The alternator charges the house bank, and then overflows to the start battery through a VSR (combiner).
With the original configuration (2 of Gp27 with A/B switch), my house capacity was limited to 1 of Gp27. I needed more house capacity to run radar and running lights overnight, and got what I needed by adding 1 of Gp24 (and doing some rewiring).
Need more info? Just ask..