Great Idea
Changing the stock battery system is a great idea. I've done it on both my 30 and 36. You can use your current batteries in paralell as the house bank, and then you only have to buy a new starting battery (not deep-cycle), and some type of battery combiner. West Marine makes one, as do a number of others. Re-wire the alternator output directly to the house bank (+). All grounds (-) are tied together with a common ground post. Wire the house bank through a new on/off battery switch to the elec panel. Wire the starting battery through the old battery switch to the starter, using the common and #1 terminals on the switch. Connect the #2 terminal of the old battery switch to the (+) terminal of the new battery switch. When you come to the boat, turn on the house bank (on/off switch), and turn on the starting battery switch to #1. If the starting battery is low, you can turn the starting switch to both, thus using all 3 batteries. When the engine is running, or the battery charger is on, they are charging the house bank directly, and the battery combiner (or echo charger) will automatically charge the starting battery, too. No need to worry about which switch is where, or worrying about blowing out the alternator diodes. The Diagram in the West Marine catalog is a pretty good one. Good Luck. Tom Soko
