Battery Isolator hook up

[gijoel]

I'm in installing a battery isolator on an M923/A2 truck. Reviewing the manuals, we "think" we have it figured out... but because we have some doubt, I decided to confirm it here.

Can someone please provide instructions on what wire lead, from alternator, is to be removed and hooked up to the isolator. FYI, we will be running to battery banks and plan to use the isolator to provide power to two equalizers; one primary (24V) for truck and one secondary (12V) for the camper.

Any help would greatly be appreciated!

 

[Suprman]

A normal battery isolator is just 2 big diodes. It will have 3 terminals, one from the alternator and then one each to feed both batteries. A battery equalizer is different. If you just want to step down to get 12 volts you can come off the 24 volt positive terminal (thru a fuse or breaker of course) and feed the 24 volt input on the equalizer and you should have 12 volts at the step down terminal.

 

[gijoel]

I may have cause some confusion with my original post. I plan to run two battery banks. One will be primary for the truck and the secondary will be for the camper. I purchase the battery isolator as to charge the primary bank first and the camper bank secondary. Since I am using the 24V alternator, I plan two hook up two equalizers. The equializers will ensure batteries stay charge, but provide the truck cabin with the required 24V and 12V for a stereo, 2m/440 radio and some other things. The secondary battery bank will be only for the camper; lights, microwave, fans, etc. So back to my original question, what wire lead do I use from the alternator as to wire in the isolator?

I hope I cleared up what I am trying to do? I know, novices and electricity... bad idea.

 

[Suprman]

I don't know if the original alternator will handle all of that. It has a sense line that allows for voltage regulation which will need to stay on the truck side. I believe there is a charging wire that comes off the alternator and goes to the positive on the starter. I believe this is the main charging wire. In theory you can extend this wire to your 24 volt battery isolator, then take one of the outputs back over to the starter positive. The other side of the isolator can go to the camper system. I would advise adding breakers all around for extra protection. The equalizer should have a wiring diagram there are usually 2 different ways to run them.

 

[gijoel]

Thanks! That is what we thought. I may upgrade to a 100AMP alternator. Circuit breaks will be installed all around... I learned that a long time ago!

 

[Suprman]

I have some 24 volt 170 amp alternators coming in a few weeks. The mounting looked very similar in the pics I am hoping they will mount up easily. They are a modern design used on one of the mrap trucks.