Need help wiring an onboard charger with battery switch

[troyo]

This is my project this weekend. I have 2 batteries now with switch, and want to add an on board charger. Any pros or cons to doing this ? Any help would be appreciated. Thanks .

 

[Silvertip]

Re: Need help wiring an onboard charger with battery switch

It's done all the time and there are several ways to do it. How you do it depends on whether you will use a one or two bank charger. Instructions will be provided with the charger, or do a search on "battery switch" and "on-board charger" wiring diagrams.

 

[Boatist]

Re: Need help wiring an onboard charger with battery switch

I wired Mine thru a battery isolator so I can charge both batteries with out turning the switch.<br />My alternator charge goes thru the isolator, The charge line from My truck goes thru the isolator and My charger goes thru the isolator. <br /><br />Advantages if someone turn the battery switch even thru off with the motor running will not blow the alternator diodes. Disadvantage is should loose between .3 and .7 volts from the charge voltage. I have tried to measure this but not been able to do so.<br /><br />If you do go with a battery isolator then the charger plus line goes to the common post on the isolator. Then output 1 goes to battery 1 connection on the switch and output 2 goes to battery 2 connection on the switch. <br /><br />I have had very good luck with mine on my 1980 boat and have not had a battery that did not last 6 years.