Using Solar Panels??? Page 3 (From TapaTalk Forum)

I’m sketching out a diagram for installation and parts now, but I’m looking at about 500 watts on the roof and $3-5K for everything. Jack Mayer’s site provides brand recommendations and he’s the guru on these forums. He recommended a couple vendor/ installers. The one in Florida, John Palmer, and I have spoken and I’m using John for my parts and install. John carries what Jack recommends. From what I’ve learned, it’s KEY to have the install done correctly, or risk negating significant system capacity due to under or erroneous wiring or component mismatches. I learned everthing I needed from Jack and HandyBob’s site on solar and I know little to start. Seems like Morningstar controllers, Magnum inverter/chargers, Lifeline batts are recommended and not sure on panels yet. As your needs seem so little, it may make sense (from what I’ve read) to upsize for future increased capacity.

jdpm wrote:I’m only interested in a 100 watt system for my intended purpose.
For example, on EBay there is a Go-Power GP-RV 80 watt/4.6 amp solar kit $528, EBay item number 261330044231. Then there is a Windy Nation 100 W P12 100 watt 5.7 amp kit for $166, EBay item number 251349256079. That a huge spread in price.
Anyone have any suggestions or input about either of these systems or a decent 100 watt system? Thanks, Phillip

Phillip:

We had the GP-RV-80 on a previous rig, but went for the GP-RV-95 and 95E expansion kit (a second 95 watt panel). The RV-95 uses mono-crystalline construction and is one of the more efficient panels on the market. In addition it is compact in size, and with our short rig, with 2 AC units, and a satellite dish, space was a premium. I think opinions from other forum members who have more experience with panels, controllers and wiring is of great value. As you cited the Go Power brand, i thought I would chime in. We have had no issues with our panels and service from Go Power on a previous inverter we had.

Rick

-Carl

As a rule of thumb. 1 watt of solar for each 12 volt battery amps. I have (6) interstate 6 volt batteries @ 232 amps each = 696 amps. I installed (5) 140 watt solar panels = 700 watts.

Lillyputz

Jpcovert1 wrote:Lillyputz is on the money. 100-200 watts of solar is almost a gloried trickle charger. It seems that there is no such thing as too many watts. For most RVers the limitation is real estate on the the roof (assuming you are not keen on a portable array) and whether to wire in parallel or series. X2 on Jack Mayer. Tons of great info.

Is that a bad thing if that is all one is looking for? I am not looking to RV off the grid. I simply want to be able to maintain a “full” battery once I turn-on the inverter to run the refrigerator for up to 8 hours max prior to hitching up and leaving on a trip.
I am using 2 6 volt batteries. The fridge draws 3 amps upon compressor start-up and then only about 1 amp while running. The inverter draws 1.4 amp with no load. The fridge takes only 3 to 3.5 hours to cool down from 90 degrees to 37 and -2.
Correct me if I’m wrong please, but will a panel that puts out 5amps (remember I’m in FL) maintain the battery full while the inverter is running the fridge or is there something I’m not understanding? I appreciate the help. Phillip

outwestbound wrote:Does anyone know if federal tax credits area available for RV solar installations? I wonder if the RV needs to be classified in the state of domicile as a “residence” in order to get credits, if available. I’m looking to buy a system in Florida, so I assume there won’t be state credits (as there is no state income tax).

We got the $3000.00 Tax Credit for our Solar install on our Carri-Lite year before last. It has a deadline for filing, not sure when it expires. This was in Texas and we are full-timers so that may make a difference.

outwestbound wrote:Do you recall whether you had your RV as a primary or secondary residents in Texas?

We are Full-Timers, so that is our “Only” residence. We have a home base at an RV Resort in N.E. Texas for 4 to 5 months during winter and we are registered as residents of Texas (never lived anywhere else).

B.W.

What you describe should work just fine and also allow use of Bigfoot without depleting the batteries too far so long as batteries are well maintained, it hasn’t been cloudy for the past week, and you don’t wait until late afternoon to first turn on the inverter and frig. Remember, there will also be slight 12 volt draw from lp gas/smoke detectors unless those are isolated.

This means you can get by with a cheaper and simpler solar controller – just be sure that it plays well with the 120 charger when rig is plugged into shore power (most but not all do recognize another charger on the system and adjust accordingly).

I would still recommend a junction box rather than single connection on the roof and much larger cables than your setup suggests between the roof junction box and the controller. This will make it very easy to add panels, and, if a lot more, swap out the controller, if you find the need to upgrade.

Some pricing is due to panel design, with some better at low angles (very important further north during shoulder season, but also great for getting the last drop of charge before the long night of boondocking. Also important when just a part of the panel is shaded, some can tolerate little without significant degradation of output. The above poster lauded to those qualities.

jdpm wrote:Is that a bad thing if that is all one is looking for? I am not looking to RV off the grid. I simply want to be able to maintain a “full” battery once I turn-on the inverter to run the refrigerator for up to 8 hours max prior to hitching up and leaving on a trip.
I am using 2 6 volt batteries. The fridge draws 3 amps upon compressor start-up and then only about 1 amp while running. The inverter draws 1.4 amp with no load. The fridge takes only 3 to 3.5 hours to cool down from 90 degrees to 37 and -2.
Correct me if I’m wrong please, but will a panel that puts out 5amps (remember I’m in FL) maintain the battery full while the inverter is running the fridge or is there something I’m not understanding? I appreciate the help. Phillip

Lillyputz

-Carl

The 2 smaller panels are mounted at the front of the roof and the larger 260W is at the rear. I fashioned a combiner box from a PVC electrical box and a couple of BUSS bars. The panels are connected by 10 ga wire to the combiner box and then by 4 ga to the charge controller. I also put in a disconnect which can completely isolate the solar from the batteries.
The inverter and transfer switch were already in place when we bought the trailer, installed by the previous owner, but I did the rest myself.
By doing the majority myself, I figured I saved at least $2000 over having a dealer do it and wound up with, I think, a much better installation.
Also high voltage grid tie panels are much cheaper than 12V panels typically sold for the RV market. Cost per watt of these panels is only around $1! The downside is the charge controllers tend to be a bit more.
As things stand right now, my main concern is that I have more panels than the controller can handle in full sun! I probably should have started with the TS-60 but at the time I had no intention of going to more than 500 watts. The TS-45 can handle more input power though and will limit the output to rated maximum so I hope I will be OK. We do a fair bit of spring/fall camping when the sun is lower on the horizon and I wanted to maximize my capability for that time. I figure if I start to overload the controller in the middle of the summer I can just disconnect one panel if I have to.
All 4 batteries are mounted in the front compartment. That way I can keep the side compartment for hoses and stuff.
All told it was a fun project 

Other images are viewable in my photo album.

Rick