Battery switch wiring question

[Cuskmaster]

First of all, let me say that these forums are great! I had a months- long problem (thanks to some bad advice from a dealer) solved in a couple of evenings and help from the folks who troll these sites. O.K.- now my question- I have a Perko battery selector (off/one/all/two) and 2 different batts- one troll, one start. I plan to connect my starter hot wire AND a wire coming from a bus with all my electronics (bilge,lights, ff, d-riggers,12V troller, etc,)to the common terminal on the perko, and ground all negs. Is this O.K.as long as I never switch to OFF while motor is running? The perko has a "make before break" so I thought I could use the altenator to charge my trolling batt after starting with my starting batt. If this is O.K. to do, then can I put the pos lead of my charger/ maintainer on the common post of the switch and charge the batteries at home one at a time, depending on the position of the battery switch? I know you guys have visited this type of question a ton of times, but I am still, regretfully, in the dark! Thanks in advance for any help that's offered!

 

[duck-n-pond]

Re: Battery switch wiring question

If I read what you are asking correctly, it seems simpler to me to get a battery isolator such as used in an RV. This isolator charges both batteries when engine is running, but only draws starting current from the starting battery, trolling current from the trollong motor (I think...check that one out), all without the need to play with or forget switches. Worth looking at.