Wiring for 2 batteries and trickle charger

[BOAH]

I have a '73 Evinrude 115. I have a battery that's labeled starting, trolling, deep cycle so I guess it's an all purpose battery. I bought a second one just like it as a backup. I would like to add a fish finder and a radio to the second battery eventually but first thing is first.

I have a battery selector switch that I haven't installed yet and I have an Atwood 1.5 amp maintenance charger (trickle?). It looks pretty straight forward on how to hook up the battery selector, but I would like to know the correct way to add this charger into the equation so I can mount it and just plug it in when I'm home.

If you could point me in the right direction, I would appreciate it.

Thanks for your help!

 

[Lyle29464]

Re: Wiring for 2 batteries and trickle charger

I dont know that I would hard wire that charger into your system. I think I would just turn the battery switch to both and hook the clips to any battery and unhook it before I started engine. Also I would check the book to make sure it can stay on all the time. ( fully automatic)

 

[bruceb58]

Re: Wiring for 2 batteries and trickle charger

Just get another charger. You don't want to leave battery selector switched on the both setting in case something happens to one battery. If you lost a cell in one, it would bring down the other battery to the same voltage.

Even better, buy a 3 stage 2 bank charger. The charger you have may cook the battery if left on indefinitely.

 

[BOAH]

Re: Wiring for 2 batteries and trickle charger

Actually, I was thinking that I would just plug it in for a day or two when I brought the boat back. I have to run an extension cord to it so I definitly would not leave it plugged in indefinitely.

With that information, would it then be feasible to just set the battery selector to both, hook up the charger for a couple of days and then call it good?

Thanks again.

 

[Lyle29464]

Re: Wiring for 2 batteries and trickle charger

what bruce is saying is you really cant correctly charge 2 batteries at one time with a single cheap charger. You need a 2 bank charger that will charge the batteries and then just monitor them. That lets you turn the battery switch off.

 

[EricJRW]

Re: Wiring for 2 batteries and trickle charger

I'll take a picture next weekend, but I'm using one maintainer with two batteries. My solution was to wire in a switch that lets me control which battery, one at a time, is on the maintainer.

Toggle the switch one way, it charges my main, toggle it the other way and it chargers my guest. Switch in the middle and the maintainer is isolated from either battery.

I then take turns "maintaining" each battery. The boat is on a dock, which I turn the power off when away. But when I show up on Friday, and switch on the dock power, this tops off one battery (usually the main). The next morning I flip the switch to top off the other (usually the guest).

When I take the boat out, I flip the switch to the middle position to isolate the maintainer, though I suspect this is not strictly necessary.

Oh, and I mounted the maintainer under the console, so it's all hard-wired together.

PS. This is what I'm using... About $30.

http://www.oreillyauto.com/site/c/detail/SCM0/SE112S.oap?keyword=battery+charger&pt=N0360&ppt=C0005

 

[BOAH]

Re: Wiring for 2 batteries and trickle charger

That would be great if you can take some pictures. That would keep me from asking a lot more stupid questions! And if I can use what I've already got, it would obviously save me some money as well.

Thanks!

 

[EricJRW]

Re: Wiring for 2 batteries and trickle charger

Attached is a wiring diagram.

The switch would be classified as an ON/OFF/ON switch.

I did all this under the console and basically tapped into the existing 12V power bus.

I'll take pictures of the actual work this weekend.

 

[EricJRW]

Re: Wiring for 2 batteries and trickle charger

Here's the picture of the actual work.

The black and red pair wire you see running over the top of the charger goes to my second battery.

When the switch is in the left position, the output from the charger goes to my wiring block, which is connected to my main battery.

I would love to have a fully automatic method, but I already had the charger and for a few bucks worth of wire and a switch I have my own, albeit manual, bank charger.

 

[BOAH]

Re: Wiring for 2 batteries and trickle charger

Thank you for doing that!

 

[EricJRW]

Re: Wiring for 2 batteries and trickle charger

No problem. And it is on my list to clean up that rat's nest of wires. I've got gages in various stages of working, and all have busted needles, so I'm taking this on step at a time (but fully charged batteries was a priority).