270w solar world panels

Brian, there are advantages and disadvantages to going mono or poly. Same goes for going 24v vs. 12v, and mppt vs. pwm.

sportzfann wrote:
I was looking at the specs on these panels and the voltage is 32.1 volts
so the charge controller will reduce that to a voltage useable to the battery?
The RV panels I saw had a much lower voltage, so it a little confusing?
Thanks,

Yes, MPPT controller will reduce it.

Those other panels that you saw, where nominal 12V panels with voltage around 17V.

Again, with 24V panel you have to use MPPT controller.

There are few types of panels - nominal 12V, 24V and 40-something volt. And there are 2 types of controllers - PWM for 12V panels and MPPT for everything else.

As to the "cost of charge controller that would work with these" - it depends on home many 270W panels you'll get. I would consider one of Bluesky models, or a Morningstar TS45 or TS60, or Outback (if going over 60A). Check Solar Blvd. With today's panel prices and considering that you have a 5-er, I would get 3 or 4*270W.

This is a normal voltage for a 24V nominal panel. All panels from ~200W have voltage in the 30s.

Those "advertised for RV installs" are nominal 12V panels. They typically install 1 or 2 panels, maximum 280W total. If you want a lot more wattage, you will need 24V panels because using several small 12V panels will complicate the install too much. 24V panels in turn would require an MPPT controller, a more expensive type than PWM controllers that are used with a couple of 12V panels.

This is why RV dealers don't like doing anything over 280W - they follow the path of the least resistance. You get what you pay for - a small system may give you "something", a big system will give you enough to live on.

I was looking at the specs on these panels and the voltage is 32.1 volts
so the charge controller will reduce that to a voltage useable to the battery?
The RV panels I saw had a much lower voltage, so it a little confusing?
Thanks,

Yes those are the panels he has. I will need to check the cost for the charge controller that will work with these.
I was thinking I have room for two of these on roof and maybe do a upgraded battery setup (I have two six volts Battery's now.
would like to set it up so I don't have to plug in my trailer while at home,
And have enough to run all my essentials while boondocking for a week.
Thanks, for responding Brian

It could be ok, but be careful

That type of "24v" panel needs an MPPT controller (which bucks the voltage down to "12v" for charging the RV batteries) which is expensive ($300+), so do some budgeting around that for the total cost.

Big panels need roof real estate that is not in the shade of all the things that stick up on an RV's roof, so that can be tricky. Use cardboard about 3 inches high like a panel same size and try it for fit and shade at different sun angles.

Are you referring to these?

http://www.solarworld-usa.com/~/media/www/files/datasheets/sunmodule-plus/sunmodule-solar-panel-270-mono-ds.pdf