Can I switch from 1 to ALL with a Perko 8503 switch?

[USA591]

Hi There Friends,

I was curious what your thoughts were on switching battery banks while the engine is running (at idle)? The instructions say it has a "make before break" function that will save your alternator, but I've also heard from a boat tech saying NEVER switch between 1 -- ALL -- 2 while the engine is running. That doesn't make any sense to me, though: I've always thought that you start on battery 1 (or 2) and then switch to ALL while the engine is running in order to charge them both.

In this scenario, if you save battery 2 for your house battery and ran it down and then started the engine in ALL position, the fact that it was dead would hamper the "good" battery's ability to start the engine, no?


Thanks!

-p

[MarkT]

I have been a marine mechanic for many years and never did change while running. An old school alternator/ starter rebuilder told me that years ago. With a single engine boat I teach my customers to alternate batteries. You can use battery 1 for example one day and 2 the next. Or run out on one and come back on 2. If you are going to anchor for some time shut off one battery to make sure you have a fresh one to start.