Solar question

YES........

Richard

Thanks, I was afraid they would buck each other

At 85 solar watts there is no wonder that you are having marginal battery recharging. General rule is one watt per wet battery amp hour. While you can do as you propose, you’d be better off to use matching panels of a larger capacity and one MPPT controller. Remember folding solar panels need to be setup every morning and taken down every evening or they grow legs. Roof mounted panels are usually working before you come outside in the morning.

Under the counter is a terrible place for a controller. It should be as close to the batteries as possible but not in the same compartment with wet batteries. With AGMs or Lithium they can be such.

If you have space to store them, another good solution is to buy USED solar panels for 50-80% less than the cost of new panels. Then, buy some wiring, a fuse, and a solar controller and you have a very inexpensive portable solar setup. If it ends up growing legs and walking off (stolen), you won't be out much (especially if you can keep your charge controller somewhere safe/secure).

I have purchased 250w working panels for as low as $35 each. Check your local craigslist, facebook marketplace, etc. Test the panels before you buy, but there are no moving parts and they should last a long time (20yrs+).

And to answer your question, yes, you should be able to hook up separately from your existing solar.

Good luck!
Chris

Lwiddis wrote:
At 85 solar watts there is no wonder that you are having marginal battery recharging. General rule is one watt per wet battery amp hour. While you can do as you propose, you’d be better off to use matching panels of a larger capacity and one MPPT controller. Remember folding solar panels need to be setup every morning and taken down every evening or they grow legs. Roof mounted panels are usually working before you come outside in the morning.

My roof mounted 85 watt does exactly what it was intended to do. Just changing the way I camp. When it finally dies I will do as you suggest. Until then just looking to extend my stays. Where I stay it is highly unlikely that anything would walk.:)

I did think about just replacing the roof mounted panel with a larger new one, but the existing panel is still producing and I hate to just trash it. It still buys me 1 extra day without using a generator. Thanks for all the input.

AidenJ wrote:
Thanks, I was afraid they would buck each other

No such happening. No different than having shore power plugged in with converter charging batteries and solar panel putting power into the battery.

The battery will suck up as much power as it needs and both charging devices will provide power as long as the battery is accepting it. When battery is "full" it's voltage will rise and shut charging devices down to float voltage. One may switch to it's float output sooner than the other due to slight differences in how they read the voltage but when the battery is "hungry" both will peacefully coexist and feed the battery.

Microlite Mike wrote:

AidenJ wrote:
Thanks, I was afraid they would buck each other

No such happening. No different than having shore power plugged in with converter charging batteries and solar panel putting power into the battery.

The battery will suck up as much power as it needs and both charging devices will provide power as long as the battery is accepting it. When battery is "full" it's voltage will rise and shut charging devices down to float voltage. One may switch to it's float output sooner than the other due to slight differences in how they read the voltage but when the battery is "hungry" both will peacefully coexist and feed the battery.

Thanks for helping me understand. I've been holding off making any purchase.

I've been using a 120 watt portable panel for years. It works great. I bought another 60 watt panel to use beside it.