Solar Panel question?

An idea I had last night was a hybrid, one mounted 200ish watt panel and one 200ish watt portable panel. Anyone do this, heard of it or have thoughts? Wiring would be simple but would it be an issue with the control? It would also solve half of the storage problem and at times the one mounted panel would be enough.

rocmoc n AZ/Mexico

If the price and overall size were somewhat comparable I would go with three panels for the redundancy. If a panel were to fail you would still have 66% of your capacity.

As far as fixed panels vs. portable, I'm still trying to figure that out. Right now I have a three-panel array on a frame that I can place up to 35 feet from my camper. But storage and convenience is an issue, as is the potential for tripping over the cord. I might end up mounting them on the roof and putting up with less output.

Phoneguy, are you doing this and if you are, how long are your cables? How far can you reach for the sunlight?

My tv is a pick-up with a topper that has doors on the sides. This is where I will keep my batteries,charge controller,and an inverter for the AC. The panels are on the top of the topper. I will park in the shade and use a (start out w/50') of shore cable to hook with the house cable. So in theory I can park the truck 50' from the camper to be in the sun. Seems how the batteries are in the back of the truck I could also run a cable to the truck battery and alternator but only as a backup to solar. If you do this,you don't want to do it very long and make sure you have amp gauges everywhere so you can monitor the charge. Deep cycle don't like to be charged to fast.

If you are running the air 2+ hours per day you don't need solar.
Maybe a better converter but not solar.

Thanks for the posts. I didn't think about the shade issue of a single panel vs multi panels. Being in the sun and not being able to take advantage of shade is an issue that does give me concern. Since a lot of our camping is in warmer weather requiring the gen to be ran for AC during the peak of the daylight, Solar does not pencil out as well. It is not that unusual for us to camp in 90 degree weather. Even if the windows are open and fans on, the Motorhome can turn into an oven. AC is the only option. Still thinking about this and trying to make the correct decision. Maybe the unmounted idea but where to put the panels when traveling? Phoneguy, are you doing this and if you are, how long are your cables? How far can you reach for the sunlight?

Thanks,
rocmoc n AZ/Mexico

MPPT controllers of decent quality are coming down in price to a point where there isn't any reason to bother with a PWM controller, especially on the limited space of some rigs where one needs every watt possible.

Shade will kill panel output, where even a little bit on one cell will cut the panel's output by 90%, so multiple panels avoiding shade is a wise thing.

Also, don't forget wire gauge, as almost all solar installations run too small a wires, and voltage drop can mean the difference between a good battery charge versus never getting near 100% SOC, especially the wire run between the charge controller and the battery bank.

Easier IMO to mount one 210w panel vs 3x 70w panels.
The three may have cables to interconnect in series or you need a combiner box.
Series or large 24v panel does need a more expensive MPPT controller.

If you have odd space to place the three with minimum shade issues vs the large panel next to a shade item then the three will be superior.

My personal opinion here,as I have done extensive research on solar. It mainly depends on what and how many batteries you want to recharge. Simple 12volt parallel batteries can get by with smaller panels and a simple PWM charge controller. Anything of 24volt and above larger panels. If you mount this on top of rv then you will always have to park in the sun and no shade. Personally I want my panels off the rv. Now you have to think about wire size and how far away from the batteries you will be. The shorter is best. So to answer the question, for me it's no question larger is better. MPPT charge controllers cost more but in long run best.

There is no better because there are many other factors. My general observation is that the solar industry is more involved in commercial applications than small panels. So with larger panels you can pay less per watt and have more watts (at least on my roof). Larger panels often mean a more expensive MPPT controller.

The less connection is the better way to go