Happy New Year!

I am in the Arizona desert where the days are nice and sunny but the nights are cold. I expected my camper batteries and my rooftop solar to be adequate for continuous  boondocking. They seem not to be and while I'm looking into a couple of explanations (maybe an issue with the controller charger or it may be the angle of the sun in the SW during the winter), I have a question about a short term solution so that I don't need to change my plans over the next two weeks or so.

I have 2 100 AH lifepo batteries and 180 watts of solar on the roof. I'm mostly running only the fridge and heater, on propane but of course I’m aware that also uses battery power, and all the other things that run without me noticing. The solar panels are not fully recharging the batteries each day so after about 6 days I'm pretty low on power.

I also have with me two relatively small “solar generators” and a dedicated portable solar panel for recharging them that I can move around to face the sun. They are also easily taken to a library or coffee shop where they charge up rather quickly. They do not have their own 30AMP outlets.

Can I use the solar generators to top off my house batteries and, if I can, should I use the progressive surge protector or just an adapter?

As always, I much appreciate this forum for smart answers.

Julie

You really do need a reliable way to charge the batteries when solar to the panels on the roof is insufficient. Adding a couple of panels such as a Renogy solar suitcase to add more solar for charging would be better. More likely, a dual-fuel generator that you could run on propane would be better since you would not need ot carry gasoline. That is what I do. We also get the batteries charged while driving as I added a dedicated circuit and I do have a Renogy MPPT charge controller that will accept input from the roof solar panels or from the vehicle to charge the 200 AH battery that I have. Since it is a DC to DC charger, it can boost the alternator voltage to fully charge the LiFePO4 battery.

This is the one I use. It is expensive, but worth the price.  https://www.renogy.com/dcc50s-12v-50a-dc-dc-on-board-battery-charger-with-mppt/ - https://www.renogy.com/dcc50s-12v-50a-dc-dc-on-board-battery-charger-with-mppt/

Thank you for the replies. I had done this trip a few years ago with less battery power and only a portable 100w Renogy suitcase and I was fine. From what you've both said it seems to me like the problem is the winter sun and not an equipment malfunction.

As I said, I'm looking for a short-term solution so I don't have to change my plans over the next couple of weeks and hoping to use what I have with me. The "solar generators"  have a dedicated (but small) portable panel.

I know they are batteries and not generators and I hate that they have named them this but if I had called them batteries you would have been confused. I also know they are small but all I need to do is stretch the time; even getting a couple of extra days helps because then I only have to move to recharge only once instead of twice. Based on your replies I did check my Go Power solar controller and it is MPPT

My question is, can I use them to charge the house batteries and if so, should I use my surge protector?

Yes, but... if you are plugging your power cord from the camper into the "generators" you will lose power in the conversion process because you are going from 12v to 110v via the inverter in your solar generator, then 110v back to 12v via the converter in the camper. So yes, you can charge your house batteries with solar generators, but it is inefficient as heck. You would be better off charging another battery with a solar panel, then swapping out the house battery with the freshly charged one.

Since your power is already "clean" coming from the solar generator battery, there is no need for the surge protector.

If it's more than one panel, switching to a MPPT controller will help a lot, because the MPPT controller will allow you to charge in diminishing light. The MPPT controller will allow you to connect the panels in series, which will increase the overall voltage output of the panels.

Second, what is the angle of the sun where you are? This time of year, it will be relatively low, and increasing the angle will make a huge difference in the solar output. I ran a broadband business for quite a few years, and all of our remote POPs were solar powered. I set the angle of the panels at 60° and had plenty of power even in the low angles around the winter solstice (hardest period is December 21 +/- 30 days).

If all you have is a fixed rooftop panel, I would seriously consider a suitcase/portable panel. Even in the summer, you may be camped under or near trees and your rooftop panel will be ineffective. A portable panel gives you that ability to place it out in the sun. Make sure it has it's own controller. They usually come with clips that can be clipped directly to the battery giving you maximum charging efficiency.

The "solar generators" would not be great, but if that is all you have, go for it. You can get an adapter to adapt the power cord from the 110V outlet on the units to the 30A trailer cord easily enough. Just don't expect to do more than add a little power to the battery and don't expect to fully charge it from the two units. Be sure to monitor whichever one is connected so you know whether it will allow this type of use or not. Turn off everything but the converter. so power is only going to the battery.