solar panel wiring to multiple house batteries

[wideglide2k]

Hi guys. I have just purchased a 15 watt solar panel and a 5 amp charge controller which will NOT be permanently installed in my 2003 Itasca RV. The wiring from the panel to the charge controller is self exploratory. My question is wiring the charge controller to a two battery house bank. My gut tells me to hook up positive on battery 1 and negative on battery 2 so the charge goes to both batteries. However, since my knowledge of lectricity is just enough to make me incredibly dangerous, I wanted to ask the forum for some guidance and advice. Thanks for your help.

[OneRVer]

Well I do don't have solar panels so might not be much help. Your two 12 volt batteries are already in parallel. Meaning you already have a cable tied to both positive terminals and a cable tied to both negative terminals. With this being said, I do not think it would not make any difference. Just be sure you hook positive to positive and negative to negative AND you are connecting to 12 volts.

[Mike Canter]

It makes a big difference if you have two 12 volt batteries in parallel or two 6 volt batteries in series. If they are two 12 volt batteries in parallel then hooking to the POS and NEG of one will charge both in parallel. If they are two 6 volt in series then you have to hook the POS to the main POS going to the MH and the NEG to the post going to ground. To double check that with a multimeter across the POS and NEG of the two 6 volt batteries you should read 12 volts.

In what you are saying with the POS to one battery and the NEG to the other will work but your theory on the current passing through two batteries is a little incorrect. Current flow is through the path of least resistance so it will travel throough the common ground which is the frame. But like I said it will still work for you.

[PHESPE]

Originally Posted by Mike Canter

..... your theory on the current passing through two batteries is a little incorrect. Current flow is through the path of least resistance so it will travel throough the common ground which is the frame. But like I said it will still work for you.

Not really

Current will flow thru both connections - promotional to the resistance of each. For example if you had 2 paths One of 1 ohm resistance and one of 2 ohm resistance connected to a 12 volt source one will carry 12 amps and the other will carry 6 amps.


PHE

[Ed-Sommers]

Hook up the leads to the same posts as used for the load!

I assume you know that 15 watts just may maintain a full battery if you are lucky, and charging would be negligible.

Ed