Portable solar question

[BrianW]

Originally Posted by Carl

What it sounds like is that having my rooftop 135 watt panel/controller and "adding" the Zamp 80 watt connected direct to house battery will only give me a quicker charge. Is this correct?
My issue started one trip when parked without running for 4 days. That trip I ran the normal fridge, coffee pot, microwave, lights, but I also brought an additional portable fridge/freezer. Several days in, my 110v clicked off from what I presume to be low power in battery.

Wow, you ran all that stuff and still got four days out of your batteries? That's pretty good, IMO, running high-drain appliances like a microwave and coffee pot.

[daveb]

+1 on Brian's post. Carl, if you're not, you need to watch the battery voltage. After you use a coffee pot or microwave the voltage should float back up after a spell. It should never fall below 12.2vDC (float voltage) unless you absolutely must let it go further. At least run the engine when using those things to offset the load.

[Carl]

I have been very pleased with solar in general and in particular, the "stock" panel/controller set up. The previous 3-4 day parked stay was sunny as well. What I hoped to gain in wiring the Zamp, with its own controller to my house battery was just an added level of comfort in charging if sitting for a few days, or in cloudy weather. Also in a situation where the van may be parked in shade, but portable able to be in sun. So in your opinions, is wiring to house like above worth it?

[daveb]

Not sure. You need to test it. While the batteries are low see if one array or the other sends the opposite one into the float mode. It will depend on the controllers annunciator display. Without some kind of display you might have a time seeing if one source affects the other. It all depends on the cutoff point each controller has. It could end up being a guessing game and in the end you might loose some charging advantage. Very hard to tell. If you want to do it right, put another similar panel to the one up there on your rig, tie it into the existing controller and call it good.

[Carl]

no question the best solution is a second fixed panel 135 watt on roof. What I was hoping to gain was a quicker method of re-charging only on trips where I may need it.