Recently ordered and set up camper for a 100 folding portable solar panel... only took 8 years to add second panel. One week of fiddling with it.
When we installed our solar system in 2006 it was laid out for 2 130 watt panels. Simply due to initial expense started with 1. I sat it up with 4-way tilt to capture winter sun but rarely use-its a pain though can easily double output. Solar has been the single most appreciated addition to our camper. To this day it never ceases to amaze me watching the batteries charge during the day.
As the single panel usually, marginally, keep up with our needs, it does so much more than I had hoped. To the point Margaret couldn't justify cost of 2nd panel. Though batteries never reach full charge except in full sun during summer, they do -with a bit of conservation stay above a level that allows us to use what we want. Second panel would put us over 'break-even', compensate for winter sun, shade etc. Or, without getting on roof to tilt panel when we really need it, increase amp input. (what kinda finally got Margaret to start thinking addition might be a good thing-).
Long story short- Planned was another roof mounted panel matching the current panel, in wattage and size. Mostly to increase the input and faster charge times and to truly get closer to fully recharging the batteries during day. Ready to make the plunge started researching panels again. But, as noted, parameters have changed compared to original thoughts.
Over the years actual use has brought out more to the forefront issues other than lack of wattage input. Primary being shade. When we situate camper always try to insure rear and panel will get at least a few hours of sun or due to available spot just deal with what we can get. Second is winter/low short sun. The panel tilting can greatly compensate for both, but unless batteries are really hurting I don't bother. Lastly an additional roof mounted panel will need to be on front of camper, marginal at best-would add input but as I wont be adding tilting option and not avoiding at least partial shading (when controllable) of camper.
The use of a portable panel, though an expensive option, started to seem more & more practical, would address these issues. Allowing to chase the sun, especially during the winter. Parked under or panel blocked by trees, portable might be able to find sun. Being angled instead of flat and ability to point at sun- could actually see more amps from smaller panel than our current roof mount one. My last justification was if it really gets old setting up portable unit I will hard mount on roof or make the allowance. I have a spot picked out.
Thats my convoluted reasoning for the addition to be portable. Recently 100 watt folding panels I was looking at went on sale so ordered. I was looking at smaller ones for ease of storage & handling, also some larger for wattage. The 100watt seemed best trade off as far as weight, size and wattage. Cost wise probably double over fixed mounted or building your own portable system.
Enough preludeIt arrived couple weeks ago. Initially was pretty stoked with the unit, quality of components was better than expected, operation of the legs etc.
Size smaller that anticipated. It came with a really nice case, overall size less than 30"x22"x4", finished weight ~27#. After seeing it in the case one unanswered question, where to store, became apparent. Easily fit back side of dinette seat between it outer outer wall, right next to the door. Cool, wont have to move our pink Flamingos...
Panel came with 10amp controller, cabling and fused battery clamp cable w 50 amp quick connects. Plug & play.
As we have actually been getting some rain unable to check out potential on camper so first break I sat up the panel just inside garage door and connected new panel to truck. HOKEY SMOKE. I was getting 5.9 amps with a ray of sunshine poking thru the clouds hitting directly on panel.
As the clouds drifted in, the voltage dropped, so I re-positioned to get more light on panel as I was checking out the features of the included controller. The controller has all kinds of information and configurable features. However when I moved the panel the controller went off. Umm, thinking just loose connection, checked everything and it didn't take long to figure out it was the cable where it entered the connection box of panel. Wiggle it and controller would go on/off. Packed it up and took to shop. From there it all turned to poop.
FAILWell not so much poop (now that its done), because my 'plug & play' morphed into a customized unit more suited to its purpose and justification. However that just simply was not the plan.
Why didn't I just return? Well when I figured out simple problem I fixed it before I got a response from retailer. I don't want to fix another. But in the 'fixing' I realized there was a lot I could do with the 'parts' on hand to make this more purpose built.
Im not going to berate the supplier of this panel, nor am I advertising. They did offer a new unit at substantial discount. But there are some serious quality control issues in my opinion, though strictly to the final wiring. Which I fully related with words and a lot of pictures. As Ive not seen anything but pretty positive reviews I can only assume mine was a fluke. If it were not due to my initial impression with the 'suitcase' and hardware I would have returned simply because of the wiring. But as I thought about it, after verifying the panels actually work, my plans likely void any warranty so Im keeping.
Though I first fixed then subsequently changed, as most would return only showing what I found, and how I 'fixed' if you had this or similar panel what you 'might' look at.
But back on point, Initial fault:
Just sloppy, good portion of wire strands loose
But the real problem, second/middle black wire..
The black wire from opposite panel is ON TOP of the screw terminal. It is setting between screw and side. OK.. simple fix, loosen screw, place wire UNDER terminal, re-tighten. Then it occurred to me-why? moving the other cord outside of connection box caused wire to move. I mean they are captured in a gland that is suppose to both seal and immobilize wire, even unconnected it shouldn't be flexing inside?
Disconnecting all wires to re-attach cleanly I started to loosen caps that restrain wires- unneeded, both cables just slid out.
Ummm...The cable from panel to controller (that was connected) has a larger OD than ID of cap. It will not go thru. It was sliced at a bit of angle that sort of allowed it to protrude into cap but cable was not restrained.
The other cable (that wasn't connected), panel to panel has a smaller OD, it goes thru cap but caps cant tighten enough to compress on the small cable. I pulled the lid off the other connection box, pull on cable slightly and its pulling at screw terminals. So they weren't restrained.
All of the cables are 1.5mm x2, the short piece that goes from panel to panel and controller to battery are smaller OD, The other cable Just fatter OD?.
Again simple fix
How it supposed to work. Small piece of rubber sleeve slides over cable, as cap tightens pushes small cone washer compressing the rubber sleeve on cable. However due to smallness of cable OD and the very short travel of caps it doesn't. IF the thread wasn't so short on boxes it would work.
My fix; short pieces of shrink tube to increase the OD of the too small cable. Worked well. On the larger OD cable simply increase the ID of cap enough for wire to go thru, but...
By this time I pretty much had decided to remove the controller from the panel, install in camper. Hard wire the quick connect to controller In and hardwire the controller to battery.
This would do 2 things, put the long run of wire on the higher voltage side (as it should be IMO) and place the non water proof controller inside camper. I guess 3 things as now I can install the smaller cable directly instead of boring cap.
Which i did. I also decided that a fuse between the cable thats being handled/laying on the ground has the potential to be easily damaged-cheap insurance. (If hardwired on roof I would/will remove).
So cable fused at both ends. When I hardwire controller to battery(s) Ill also fuse (where its really needed). But never got that far...
Thats my Fix. If so inclined, easy enough. However I didn't even get the lids back on the connection boxes and I changed the whole direction again.
New & Improved PlanFew things:
1. Since I'm removing the controller from panel, I'm not seeing a reason for using it, other than I paid for it. Connecting directly to our existing 30amp controller would be a lot simpler. Run cable from controller where it can be accessed to plug in the portable.
2. Second is the supplied cable. Its only 15' long, which is going to really limit ability to place panel away from camper in the sun. Since the cable between panel and controller is now on the higher voltage side I could increase the length a bit without affecting the output as much.
3. Not part any of panel issue but I am reinforcing the frame. It is possible down the road that I will somehow make a fixed mount to 'hang' the panels from on side of camper. Mostly so when we go for a walk they don't and/or for the elevation. Only some vague ideas how that might be done. I may not do but as I discovered the frame is assembled by inserted corners, much like screen/cabinet door frame, Likely not a good idea to 'hang' from. Since I'm here it cant hurt.
4. Seriously caulking out panels. Only an issue as far as putting panel away but the front of frame to glass is unsealed, it will hold quite a bit of water. Also the frame itself, large open channel, drilling drain holes in bottom of frame.
So with that off to the hardware.
Rewired Well not finding locally 2 wire 10 or 12ga cable opted to use extension cord for now, I can use it in the shop later. Nice cable but its only 14ga, Couldn't justify cost or bulk of 12ga 3 wire cord. Only marginally better than the supplied 1.5mm (15ga), but will allow me to wire and test. Makes no sense adding andersons to the temporary wire so using the 110v ends for now.
Short tool cord with male end is from controller outside. Cutting the 50' cord to 20/30' pieces. Adding the 20' with female end from panel (cause I cant turn off its output). Add new female end to remaining 30'. So I can plug panel directly with 20' or add in the 30' extension when needed.
And controller & associated wiring removed.
Rewired with the 14ga.
And tested to verify it still works after 'fixing'.
Curious to see the voltage drops I should expect or inducing, my highly scientific testing. Curious. Pretty cloudy, no direct sun, but bright enough to see some numbers.
Placed the supplied controller back in the loop at end of 20' cord, small M/C battery just off to side. MultiMeter is direct from panel.
What I'm seeing is about ยฑ0.8 voltage drop between panel thru 20' wire.
ยฑ1.2v with added 30' cord (50' total). Measure every which way with the sun in/&out so at different panel voltages, but consistent in the voltage drops. Metered also to verify, I was expecting a lot more thru the cord, especially when adding in the 30' or combined thru 50' of 14ga wire. Loss in trade for reaching sun- not an issue.
I can live with that. Real difference in loss in reality is, the voltage drop and charge rate is in comparison to what I would get if I cant reach the sun. Bigger cable will minimize but I wasn't expecting this.
Ok, I see the losses, but I don't know what I 'added' so rewired the controller back to panel and wired as it came from factory. Obviously less loss between the 30" piece of cable panel to controller than the 20' I'm using, I showed about 0.2v drop. However the output from controller thru the supplied 15' was another 0.5v.
Conclusion:
All this tells me is using the added length of wire with controller at end of 20' or combined 50' verses controller on panel with output thru 15' of wire appears almost a wash. Either the slight increase of gage or more likely being on the higher voltage output side, added length doesn't kill the charge, virtually unchanged amp rate showing on controller.
Installed on camperSnaked wire from outside cabinet up to reach controller, then pulled down to reach inside light box below controller. 2 hours of fun.
Made a small panel as I cant get to back side to hold a switch & fuse holder. Strip cable back about 18" and cut the power leads to run thru switch & fuse. The white return will go direct to controller.
Pre made fuse panel. I sat a Sees candy beside, thought make a nice presentation but I ate it. Not shown but I bent the fuse holder tab 90ยฐ to be inline with holder body. Soldered the incoming power leads, shrink tubed the connection then shrink tubed the cable to fuse holder body.
As I have an extra wire in the cord (ground), where I cut wire I soldered the black & green together, thinking might offset the added fuse/switch and connections. Went back inside panel connection box and connected the green to power fuse. Significantly reduced the resistance though I don't know what affect if any will have on solar as the return is single 14ga. But it was there so using.
Fished the wires back up to controller and installed the panel. So fuse at both ends, switch between controller and lead to portable.
Additional 7' of wire. Mostly switch is to turn off/on portable (& wiring leading outside when not used) so that I can 'see' the input of portable.
Proofs in the PuddingAnd the whole point of going portable...
Turned on a few items, bumped the gen starter to get solar into charge, Batteries were in float. This is our roof mounted panel, best it can do 3.1amps. Sun is pretty low in the sky.
Turned on the portable..7.8 amps at controller! 4.7 amps from portable. Whoo whoo! Excited seeing a number greater than the best 7.6 from roof panel.
Enough to warrant climbing up on the roof and tilting the main panel and see some real higher numbers. Roof output rose to 5.8amps, portable still at 4.7amps for a combined 10.5amps! Just seeing the numbers- Wow is all I can say.
Thats compared to If I had added another 130 watt on roof, flat-combined output might show 6.1 amps. Raised 8.9amps (3.1 +5.8 'cuz added roof panel will not be tilt-able). But more importantly, without getting on roof, plugging in the portable gained more than raising main panel.
New toys- but the potential is really nice. Being able to find sun.
I had to keep bumping the generator starter to keep the controller in charge mode and full amp, and realized I did have a few things turned on and its still going into EQ. Turned everything off and let it charge a bit.
Turned everything on in the camper except the inverter. Both roof vents, stove vent, every light in the house. Controller showed 8.3 amps. Turn everything off and it quickly fell back to 0.3 amps at 14.4 volts. Which is about the max usage Ive calc'd, ยฑ8.0 amps, though we've never had everything on at once.
Not its purpose but the controller will show added amps more or less being consumed by an item.
After letting it set a bit with everything off I again turned it all back on, including the 400 watt inverter, turned on the TV and sound bar. Amps rose to 9.8, additional ยฑ1.5amps,
which is what I showed on recently added watt meter to inverter,1.4-1.6 amps to run the TV thru inverter.
The whole time playing with this I was alternating between the 20' and combined 50' lead of 14ga wire from panels. ZERO difference in the amps shown at controller.
But the whole point is I'm burning up 9.8 amps and batteries are still charging. I'm putting back more than using. Of coarse Ive got the main panel tilted but very promising, we will never see this kind of draw, might even see days with controller going into float...