This topic comes up all the time. How does one charge the house batteries ( 12 volt systems ) when the bus has a 24 volt alternator.
The answer could be complicated like adding a separate 12 volt alternator.. or as simple as adding a solar charge controller to provide a 60 amp 12 volt 3-stage charge to the house batteries while you are driving.
Here is one idea.. Looks very good too !
http://store.altenergystore.com/Charge-Controllers/Solar-Charge-Controllers/Pwm-Type-Solar-Charge-Contollers/Xantrex-Solar-Charge-Controllers-Pwm/Xantrex-Trace-C-60-60A-1224V-Charge-Controller/p2071/
While kind of expensive, a Solar Boost 50 should work pretty well for this purpose. It is current limited so that it will not overload when hooked between batteries of different voltage, and will only draw a little over half as much current from the 24 volt system as is put into the 12 volt system.
I don't believe that the Trace C60 product is current limited; my understanding is that it will shut itself down if operated this way. It will handle limited overloads, but not unlimited ones.
We're using a couple of these with an alternator that can not put out too much for the controllers.
Good luck on your setup.
Tom Caffrey
Suncatcher
Ketchikan, Alaska
Dave, Thats a great idea. I use one of the same controllers for my solar array.
I was amused with Two Dogs input on your same thread on the other board. I dont think he has a clue of what you are talking about-
I had this idea awhile back, but don't have any experience with these units, and wasn't if you could hook them up this way. Seems like it should work, though, as the max array vdc is 55, and the unit is selectable to 12v or 24v, so it seems like you could hook the 24v side in as the array input, and set the output to 12v. The current limiting might be an issue, as mentioned, but I think it would be fine. I charge my 12v system through a 20a dc-dc converter and have blown the fuse only once, when I let the buffer battery get really low.
craig