Battery Switch Question

[Chris]

My boat (91 311) has 2 batteries and 1 switch; OFF, 1, ALL, and 2.

What is the correct position to use while running, charging (shore power), and haning out at the beach lsitening to tunes?
Thank you in advance.

[chewymalone]

Here's my two cents but I'm no expert. However, I always have hot batteries (never dead).

My 242LS has the same set-up. I have a deep cycle battery in position 1 and a cranking/starter battery in position 2. I use position 1 when anchored and listening to the radio, etc... That way I always keep my starter battery charged. I switch to "ALL" when starting and cruising.

On the trailer, I'm always switched to "OFF" so the radio and amp don't inadvertently drain the power. Of interest, my auto bilge switch is hard-wired to the batteries. It works even if the batteries are switched "OFF". That works great unless there's some water left in the bilge and you forget to pull the plug. I gave a guy's car a shower while stopping last time out.

I don't know on the shore power, but I think you'd want them off when charging. I always have mine off when on the charger at home. We just don't normally dock and use shore power and it's easy for me to use a manual charger in the barn.

Good luck!

[CObarry]

Call Formula Support 260.724.1412 and request a wiring diagram. In addition to showing how things are connected, there is text on the drawings that details how things respond for each setting of the battery switch (there are lots of other useful hints on other pages as well).

In general, when running, the switch should be set to "all" so that both batteries get charged by the alternators. When on shore power, assuming the circuit breaker for the on board battery charger is turned on, both batteries will be charged regardless of the setting of the battery switch. When floating or just hanging out for an extended period of time, turn the switch to either "1" or "2" so that the other battery will remain charged enough to start the engines.

[Iggy]

I'll toss my two cents in here too......

Mine is set up like chewymalone's. But I don't set my switch to "ALL" when starting. A deep cycle battery is not designed for the sudden discharge a starter will draw.
Also, I don't run with the switch set to '"ALL" either. A stock alternator doesn't produce enough amperage to charge two batteries simultaneously. If each alternator is connected individually to each battery, then there is no reason the cruise with the switch in the "ALL" position. And, if one battery develops a short in one or more cells you won't drain both batteries leaving you stranded.

[Car Biz]

I run mine switches exactly like CHEWY. The only diff is at home on the trailer i plug the shore power to charge the batts and leave the switch to ALL. if i turn the switch off the charger does not work.

[mopower]

My 272 will charge both batteries in the OFF position with the charger. To charge Both batteries while running I must be in ALL posiition. Mine is also strange in the fact the boat (forward of the battery switch) only sees the battery selected , yet when you start the right battery cranks the right and the left chanks the left. Found this out when I was only running one bat and found the other one didn't charge.
It's almost as though the boat was wired for one engine. I can see this if I turnone key on and not start the engine. Then start the other and BOTH volt meters will go to charge.