Solar Mythbusting: 100 Watts Solar in the Luggage Rack?

[Howesight]

I have been researching and searching for some time on line for portable or other solar panels that will fit in the luggage rack or another handy space in my Westy. This is a work in progress.

I have no intention of leaving the panel(s) in the rack while in use since I want the van in the shade and the panel(s) in the sun. My criteria are based on a few considerations:

1. Solar panel should be quick to set up;

2. If I want to camp, but don't need to set up solar overnight, the panel(s) should NOT BE IN THE WAY; This means that any indoor/inside panel storage solution needs to be carefully thought out;

3. If carried on the roof or roof rack, the panel(s) should be flush or easily removable for height reasons. (I can just get my Westy in the garage with ballast aboard (Mrs. Howesight and daughter).

Research is ongoing, but here's a reasonably-priced item from Renogy that, by my measurements, will fit in the luggage rack:

http://www.renogy-store.com/100W-Suitcase-p/kit-stcs100d.htm

Another option:

Flexible, thin panel(s) stored in the upper bed "sandwich" when driving. I would probably use 2 of these panels. They are less than a quarter inch thick. I don't need the flexible attributes, just the thinness for storage. I would add a DIY frame/easel for portable set up:

http://www.renogy-store.com/100watts-bendable-panel-p/rng-100db.htm

For those in Western Canada who are not picky about storing a folding solar panel in the luggage rack ( as I am), here's a heck of a deal in Burnaby, BC:

http://www.papsolar.ca/

His units are:
100W FOLDING SOLAR PANELS $289
120W FOLDING SOLAR PANELS $329
140W FOLDING SOLAR PANELS $379

I have dealt with this gentleman in buying a solar setup for Howesight Junior who wilderness dry camps with a 4x4. We got the 140W unit which works very well. Remember that all these folding units do not use a sophisticated charge controller, but they are so cheap that you can make up for this with more watts. When you decide to get nerdy, you can bypass the cheap controller, combine the 2 panels into 24V nominal, and use a good MPPT controller to maximize total power utilization.

While researching, I found the informative, if crotchety, blog of Solar Bob who cuts the crap so you don't have to. Here's a link:

http://handybobsolar.wordpress.com/the-rv-battery-charging-puzzle-2/

Main points emphasized by Solar Bob (he is not brief):

1. RV dealers get 80% of their solar installations wrong.

2. Mainly, they use wire gauges that are too small, both panel to controller and controller-to-battery and also battery-to-inverter (for those who use inverters), and they do installations that allow or force partial shading of solar panels.

3. Most people either buy a solar charge controller that charges at too low a rate and is not adjustable for a higher rate, or fail to set the charge controller at the correct charge voltages for the three or four stages of charging.

4. Most people do not get a proper state of charge battery monitor and never know the true state of charge of their batteries.

5. As a result, most solar setups leave the batteries chronically under-charge which wastes all the expensive solar capacity they bought and leaves users short of power and kills expensive batteries prematurely.

6. You MUST charge at voltages, current and time recommended by the battery manufacturer, not the charge control manufacturer or some other guru. These voltages and rates differ between models and manufacturers.

7. Gel Cell batteries are a poor choice for solar set ups because they can only accept a lower charge rate than AGM (Absorbed Glass Gat)or flooded lead-acid batteries. AGM batteries, with proper charge controller properly set up, charge fastest, next fastest is flooded lead acid.

8. Flooded lead acid batteries give best value for dollar/cycle. They do require monthly equalization charging to address stratification of the electrolyte. They also need to be watered with distilled water from time to time. AGM batteries are more suitable for vehicle locations where gassing from charging cannot be tolerated or physical jarring of the battery is likely.

9. Solar Bob preaches the importance of buying, before anything else, a proper battery monitor. He recommends the TriMetric TM-2030 monitor by Bogart Engineering:

http://www.bogartengineering.com/

So do many people and many happy customers. Google TriMetric TM-2030 and see.

10. Bulk and absorption charging for AGM and flooded lead acid batteries MUST be at 14.8 volts, NOT the 14.2 or 14.4 that most solar controllers either use or, if programmable, use as default settings. Some batteries bulk charge at 15.2 volts. ALWAYS use the battery manufacturer's specs for charging rates, not the charge controller information.


Here's an excellent link for learning about battery and charging information:

http://batteryuniversity.com/learn/article/how_to_measure_state_of_charge
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'86 Syncro Westy SVX

[PDXWesty]

Check here as well. They often have 120watt folding panels for $199 but they are out. Here's a 160 watt setup that may fit.

http://www.solarblvd.com/Solar-Panels-&-System..._info.html

Another topic:

http://www.thesamba.com/vw/forum/viewtopic.php?t=573136
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89 Westy 2.1 Auto

[Corwyn]

I bungee my100 watt panel to my Yakima bars. When I camp, I take it down and put it in the sun, while I park in the shade(30' cord). Simple.
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'90 White Westy ("White Lightning")
FAS Gen V 2.0
The Annual Baja Rally
https://www.thesamba.com/vw/forum/viewtopic.php?t=604813&highlight=baja

"If anything's" gonna happen, it's gonna happen out there"
~ Captain Ron ~

[Howesight]

Hey Corwyn:

You have a great and simple approach. Unfortunately, I can't use a rack and still get in the garage, hence the nerdy research.
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'86 Syncro Westy SVX

[goffoz]

[Corwyn]

[Steve M.]

[yycwesty]

I think it would be great to have a foldable panel that would fit in the luggage rack which you could plug in. Therefore, while driving you have a 50 watt panel charging things. Unplug it and then plug it into the side of the van and you can now open it up and use the full 100 watts..

[madspaniard]

[yycwesty]

madspaniard

does this unit you have fit folded in the luggage rack?

[madspaniard]

[aspendog]

Just ordered the Renorgy 100 watt folding unit. I'll be testing it out in two weeks for a trip east.
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91 Westy
02 Passat

[outwesty]

[Howesight]

Here are a few pics of my solar set up. Very happy so far.

The Renogy 100W panel, with "briefcase" fits in the luggage rack. Despite my modified pop-top, my luggage rack is stock sized.

I hard-mounted the solar charger inside where I could easily see the panel and have the charge controller at the same temperature as the Trojan battery.

I re-purposed the city water connection into a solar connector with MC4 connectors.

Trojan battery, Surepower battery separator, 80 amp main circuit breaker:

Ghetto Battery cover prevents short circuits from my under-seat items:

15 amp, 12V circuit breaker is my fool-proof "solar off" switch for those times I fail to set the charge controller setting properly for solar panel disconnect. For the Where's Waldo crowd, find the spare rad hose and spare brake hoses:

And here's why I like to be able to move my solar panel. The Howesights at Lillooet Lake where the first part of the day required constantly moving the panel. That's the price you pay for the waterfront campsite, I suppose:

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'86 Syncro Westy SVX

[Westified]

Howesight can you have the panel open in the luggage rack? If so, does it fit below the top lip of the rack so it can't be seen? I wanted my panel to be charging even when I drive to a hiking trail and park there for several hours. I would like it to be stealth for security reasons. Looks like a nice setup you have. Good price to.
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1984 Westy Wolfsburg, owned since 1987. FAS 2.0 NA engine conversion in 2022.

[Howesight]

[madspaniard]

It would be ideal to find a bendable type solar panel to fit in the luggage rack so that you can top off your batteries while parked for days or weeks at home without moving the van but the dimensions of the luggage rack don't usually match up to typical solar panel dimensions for effective use of this space.
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1991 Westy auto w/ Peloquin TBD

"The only difference between me and a madman is that I'm not mad” - Salvador Dali

[Howesight]