Help a newbie with solar panel / battery questions!

[Arnoldjeff]

Hi all. I have a 2014 Airstream Flying Cloud (19 feet). It has two lead acid batteries. I purchased a Zamp 120 Watt Portable Solar Charging System from my dealer. There are not many instructions that come with it. There is an online video on the zamp website which is pretty good. A few questions not covered:

1. how long roughly does it take to see some charge coming back to the battery...an hour...a half day, etc.

2. Also, the voltage on the meter of the zamp is a little different than the voltage inside the airstream. For example, the zamp reads 12.6 and the AS reads 12.0...does it matter?

3. Finally, I assume it is best to have the switch in the AS set to "store" instead of "use" when you are charging the battery with a solar panel. Any issue with using the electricity in the AS while you are charging (assuming you are boondocking with no electric hookup)?

Thanks,
Jeff

[Tincampers]

Those tenths of a volt are pretty critical. Did you connect the Zamp right to the batteries? Are there any indicators on the charge controller? Which controller do you have (model # and brand)? It might be that you have to setup the controller for the type batteries that you have. Some of them can detect if you are using AGM or flooded cell. You can use the batteries while charging but that will extend the time to recharge. I don't think the store/use button matters unless you are hooked up to shore power.

[Tincampers]

Here's some good reading:

RV Solar System Sizing by Actual Use

[Zil]

You have voltage drop, most likely your feed wires are too small of gauge, or too long. A poor connection will also cause this.

[Tincampers]

Yep, the Zamp uses tiny wires between the controller and the battery. If it were me, I would remove the controller from the panels, mount it near the batteries and use big wire from the panel to the controller and from the controller to the batteries.