diy solar

diy solar

Newbie needs an advise

tomek

New Member
Joined
Feb 22, 2023
Messages
6
Location
Austin, Tx
Hello,

I am looking for a review of my design.
I have a 50 Amp RV due to limitation of my roof I purchased 2 455W panels and 2 400W panels.

I want to setup as a 48V system

1700W = 2*400W + 2*455W
1 * Victron Energy MultiPlus-II 120V, 3000VA 48V
2* Victron Energy SmartSolar MPPT 100V 20 amp 48-Volt Solar Charge Controller (Bluetooth)
1* Victron Energy SmartShunt 500 amp Battery Monitor (Bluetooth)
1* EG4-LL Lithium Battery (V2) |40V 100AH | Server Rack
I am not sure if I need anything else from Victron family of gadgets.
Will my charge controller be sufficient?

Your advice is appreciated

 
Last edited:
Your charge controller is just right. The solar charge controller connected to the two smaller panels won't ever put out as much as the other controller but that's OK.

You're going to need something to step down from 48v to 12v. The Victron Orion-Tr 48/12-20 will work for that. It's only 20 amps, which could be a problem. If you have leveling jacks they can take up to 100 amps. If you retain a 12 volt battery on the 12 volt side and run the Orion into that it will serve as a huge capacitor. Otherwise, you'll need to find a 48-12 converter that handles more amps.
 
I am thinking to put 200W panel to pair with pre-wired Zamp Solar controller and existing 12v AGM battery just to keep it charged up, totally separated from 48V system to be used for 120V side of power. Reason, to go with 48Volts, wire size and cost of batteries which is very attractive at 48Vs level.

Thanks!
 
With panels that big, are you intalling them over the top of the equipment on the roof like AC and vents, etc?
 
I am thinking to put 200W panel to pair with pre-wired Zamp Solar controller and existing 12v AGM battery just to keep it charged up, totally separated from 48V system to be used for 120V side of power. Reason, to go with 48Volts, wire size and cost of batteries which is very attractive at 48Vs level.

Thanks!

If you arrange your components just right, the cost of wire on 12v versus 48v is almost nothing. Where you get some nice gains with the 48v system is that the solar charge controllers can handle more PV watts.

Your plan to retain a 12v battery works. I did the same, but for starting my generator.
 
No just couple inches of the roof surface. I found three areas I can install them using method by Rv with Tito adding couple wood screws as extra support.
Either lift them, or go smaller. Shadows will kill your output. In my present site, I had a teeny tiny corner shadow from the AC that took out 50% of that panels capacity. When I upgraded, I pushed the 200w 24v panel all the way to the edge of the trailer. Trailer is pointed SWish. With the upgrade, I have an antenna on a pole raised about 7' above the trailer. That pole shadow completely takes out one panel's output until roughly noon. I also ran two separate controllers, one for drivers side, one for pass side. Partially to help deal with shadow issues. I was reading one guy on a FB page, and his output on 4800w was less than my little 1200w system (in full sun). 10:1, shadows were a partial issue to his output. We're in this site for 4 months, so it was really easy for me to see the impact from shadows. Park your trailer E-W and climb up on the roof and look at shadows several times during the day. Place cardboard cut outs where the panels will go, and actually draw the shadow line on them. It's eye opening and enlightening. Once I started down the path of learning about shadows,, I found several solutions. My fav, raising the panel from side to side, with it being higher in the center. This severely reduces panel output on the side away from the sun, but tipping the panel on the sun side increased output. I chose to stay flat for several reasons, including working on aircon or vents, being able to walk around on the roof, and most importantly, I'm at 13'5" and couldn't go above equipment. Also a little concerned with potential wing effect wanting to lift panels off the roof.
 
Back
Top