View Full Version : Adding a second battery

04-12-2005, 04:31 PM
So I've seen several threads on stereo installs, was wondering if someone could offer some guidance on the best way to add a second battery to the boat? Specifically I'm wonding:

1. Where have people mounted the second (I have a 93 190)
2. Does the stock alternator keep up with two, or do you need to upgrade that as well?
3. What kind of switches etc are needed?
4. What's the wiring diagram to connect the two?
5. Has anyone just tried that switch from Overtons which cuts out the single battery if cranking amps dip bellow a certian point rather than adding a second?

04-18-2005, 09:38 PM
Lots of items to study at www.westmarine.com

You are looking for a battery combiner/isolator. It allows both batteries to charge when the alternator or external battery charger is providing jiuce but will isolate the two batteries when not (isolates into "starter" and "house" with "house" = to stereo in your case).

You'll spend about $80-$150 for the isolator/combiner, plus $30 supplies, plus the deep cycle battery, plus a smart charger (charges to full and then switches to trickle).

Good luck.