Battery question

Just bought a small caravan that has a 100ah battery that connects to the tow vehicle via an Anderson plug, I want to couple it to a solar panel using a MPPT controller I have, I have cobbled these together before and is quite straightforward but in this case I am proposing having the car set up remaining as is and just connecting the MPPT to the battery and connecting the solar panel when we set up, uncoupling the Anderson plug of course.
My own thoughts are that this will be isolated from the car and shouldn’t effect the controller in any way, am I missing something or will the battery voltage impact on the controller when it is not connected to the panel.
I have no desire to destroy it as it cost me about $300.
Being on the south side of the controller I don’t think the car charging is going to do anything to the controller as it will not be running through it and the solar panel will not be connected.

last edited by bunyip

OK, first remember I am not an electrical guy, so don’t know about this stuff.

I think what you are saying is that you will have your car setup in parallel with the solar setup. ie two sets of black and red wires connecting to the battery.

This is how I have my 100ah car battery setup with a 100w panel, and my 220ah boat setup with a 200w panel.

Both setups have $25.00 regulators.

If the solar regulator is working it will read the total battery charge and will crank itself down when the car charger is putting in more than it is just as it does when the battery is fully charged, That’s the theory. Seems to work.

I’m more worried about the batteries than the regulator. Even good quality brand name regulators (Victron for instance) can be had for $100 these days, but batteries are still $$$$.

We ran the car like that for more than a month last December, with no ancillary charging,.
We have lived on the boat with this setup for a total of 14 months and no problems thus far.

A proper battery monitor is a great investment and really takes the guesswork away, but it will cost almost as much as a battery.

The MPPT controller haseverything on board including a battery monitor, one of the tn
hings I like about the controller is that it is fully programmable so it can charge 12v solar batteries as well as 14.8v (?) deep cycle batteries.
I see what you have and it looks like what i AM PROPOSING, thanks (bloody caps lock).

Why are you proposing to Midge?

Because he is cute…

It takes one to know one… :blush:

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