perko 2 battery switch and alternator

[lime4x4]

can a 2 battery switch be turned between batteries while engine is running? I a mercruiser 350 engine.The switch is marked off 1 all 2. I want to move my house batteries out of the bilge so i'm going to be using battery wire that will not support starting the engine. My goal is to have the starting battery on 1 and the house batteries on 2. When starting the engine i'll move the switch to 1 then once the engine is running move it to all so that the house batteries can get recharged

 

[Splat]

Re: perko 2 battery switch and alternator

You'll need to make sure that the perko switch is the type that makes contact before switching. I can't think of the name right now, I've been up since 12:30 last night.

This will quickly become a chore every time you start the engine. Have you considered using a VSR(voltage sensing relay) instead. Would do the same thing you want, but is fully automatic?

Personally I would just do it right and run the proper size cable. It's good insurance if you ever kill a battery.

Bill

 

[flargin]

Re: perko 2 battery switch and alternator

ditto..
you can also use a battery isolator as well, between the alternator and the deep cycle battery.

 

[Boatist]

Re: perko 2 battery switch and alternator

The switch that allows you to turn between batteries is called a
"Make Before Break". This means it connect to battery 2 before disconnecting battery 1. If your turn thru off with the motor running you will need a new alternator, unless it has a properley wired field disconnect circuit.
I personally prefer a battery isolator and do not need a switch at all.
The isolator will reduce the output voltage of the alternator by about .7 volts if you do not have an external voltage regulator. Nice part is it charges both batteries anytime the motor is running. The lowest battery will get the most charge. My boat has been set up this way since 1980 and have never had any battery that did not last at least 6 years.