NO "HOUSE" BATTERY - HELP!

by Dave S
(Baltimore, MD)

Greetings:

Here is a question regarding battery wiring.

I have an older fishing boat / convertible (1993 Phoenix SFX 33) that is DC powered by two 8d cells, with each wired as an engine battery (to start a pair of Cat 3208T 375 HP diesels). The bulk of the house DC load runs off the "A" battery, while only a few, small items are powered off of the "B" battery.

My problem is that the helm electronics is wired off of the "A" battery which (obviously) is also an engine battery, so every time I crank the "A" engine, my Nav gear all resets itself, losing track, waypoints, settings, and causing who knows what kind of damage in the process. Is there a soution here with no "house" battery? Aside from the (major) pain-in-the-butt of my nav gear resetting, I have had no problems with the system at all otherwise.

I have considered rewiring the boat to have a house "A" battery and an engine "B" battery. Is this difficult - or - is it even a matter of doing anything other than just changing the main RED starter cable to run from the "A" engine to run from the "B" battery switch? The main board has an "A" powered side and a "B" powered side (including main engine breakers). How hard would it be to make this change and what pitfalls might I encounter?

Are there any other solutions (aside from constantly "working the switches")?

Thanks,

Dave S.
faust@hotmail.com