A Forum run by Enthusiasts of MidNite Solar

General Category => General Discussion => Topic started by: CharlieBecker on May 28, 2015, 12:10:37 PM

Title: How to charge my vehicle starter battery with solar
Post by: CharlieBecker on May 28, 2015, 12:10:37 PM
I have a couple questions, I'm a newbie... I have a Midnight Kidd with 4 100w panels in series, and 3 105ah AGM house batteries.

1) How do I charge my starter battery with solar without rewiring (and changing settings) each time I want to do it.  My house batteries are AGM, my starter battery is flooded.  They are commonly grounded to the vehicle chassis, so right now I just hook up positive to house battery and positive to starter battery and leave it for a day or so.  Is this going to kill my starter battery because of the difference in battery types?

2) Once I resolve my alternator issues (I think it's a loose serpentine belt), I'd like to be able to charge my house batteries with my alternator.  Again, different battery types... I've seen battery isolators that will allow charging of both, but when discharging the house batteries it won't discharge the starter battery. 

Thanks for your help!

Charlie
Title: Re: How to charge my vehicle starter battery with solar
Post by: zoneblue on May 28, 2015, 04:03:59 PM
Thats exactly what you need, a battery isolator/even charger. The better ones have mosfets to minimize the voltage drop. The real simple ones are just  voltage controlled relay or diode.

Title: Re: How to charge my vehicle starter battery with solar
Post by: Jacotenente on June 22, 2015, 10:53:46 PM
Interesting...never heard of using a vehicle isolator to charge a solar power battery bank. Why not? Should work. I want to get an isolator for my Silverado and install a deep cycle battery for accessories. Post a picture of your set up when you get it done.
Title: Re: How to charge my vehicle starter battery with solar
Post by: Westbranch on June 23, 2015, 12:24:28 AM
On a NA pickup you , say, would have 2 batteries, and the second one is for the RV...  you install a second solenoid that is only closed, passing current when the key is on and the truck running...  when you shut off the ignition the solenoid opens and prevents the RV from drawing power from the starter battery, so on any morning you can start the truck, even if the RV battery is flat...

see post 4 here it is far more detailed than I would write...
http://www.expeditionportal.com/forum/threads/63220-Recommendations-for-dual-battery-isolator-solenoid
Title: Re: How to charge my vehicle starter battery with solar
Post by: mike90045 on June 23, 2015, 06:57:24 PM
What happens when a 200A solenoid closes, with a 750CCA battery on one side, and a dead 100ah battery on the other ?
Title: Re: How to charge my vehicle starter battery with solar
Post by: EurovanCamper on October 13, 2015, 04:00:15 PM
Quote from: mike90045 on June 23, 2015, 06:57:24 PM
What happens when a 200A solenoid closes, with a 750CCA battery on one side, and a dead 100ah battery on the other ?

The vehicle would be running for the solenoid to close, so the alternator would be charging both batteries.