On Board Charger Question

[Jason 641]

I searched this topic and got a lot of great info about on board chargers. I have one more question that I did not see an answer to.

I have a dual battery (not deep cell) set up on my boat with a Perko switch with 1/2/all/off settings. I want to add a 2 bank on board charger mainly to be used as a maintainer to keep the batteries charged when the boat is stored over the winter and sometimes for 2 or 3 weeks at a time in the summer. When I am using the boat I will often have the radio on without the engine running for a few hours at a time. This is where my question comes in, If I am parked at my dock with the radio (or anything else) on can I have the charger plugged in to shore power at the same time to keep the batteries from being drained? Or should the Perko Switch be in the OFF position while charging to avoid any problems with it messing up the alternator or any other electronics on the boat? I will usually switch to just one battery while doing this so if the battery does drain I can switch to the other battery and still start the boat. I hate to put the charging burden on the alternator when/if I switch back to the drained battery so I want to get an on-board charger to take the load when I have 120v AC power available.

With this in mind would it be best for me to get a dual bank charger that has automatic charging/maintaining based on the needs of the battery? Or just stick with a low amperage maintainer?

 

[bruceb58]

Re: On Board Charger Question

I would get a 2 bank smart charger.

You can have the charger on while at the dock running your radio.

Switch can be in whatever selection you want.

Charger can be on while engine is running as well. Neither alternator or charger cares.

Running the radio for a couple hours will be an insignificant draw from your battery.

 

[sschefer]

Re: On Board Charger Question

This is an interesting question. Yes you can hook up your charger at the dock and run the accessories without hurting the batteries. Regarding dual bank charger.. Not necessary if you have a "Both" position on your switch. I have a Shumacher 80amp charger and charge all three batteries at one time. They all level off at 13.3 volts and then settle back to 12.6 in about 2 hours. You can pay 300.00 for a super duper onboard charger or you can pay 150.00 for a good portable and throw it under the seat. Either way it's onboard.. LOL..

If you have any doubts about this, give the folks at Johnson Controls a call. You'll be suprised at some of the plain facts they'll tell you. Johnson controls makes Optima's, Odyseey, Interstate and about 90% of the other batteries out there.

 

[Jason 641]

Re: On Board Charger Question

I realize the radio isn't that much of a draw, it just comes into play after the boat has been sitting for weeks or months and the batteries aren't charged good. The reason I was thinking about going the dual bank route is because when I have the boat in storage I will have the Perko switch shut off so the batteries won't be connected to each other. Plugging it in at the dock would just be an added benefit if needed.

Thanks for the tips/ideas.