Solar Camping in Vanagon

[RCWesty]

I'm in the early stages of researching some solar panels for supplemental power during longer camp trips. Any examples of use, suggestions, comments, etc?
We are interested in powering up: laptop, fan, and misc elect items. I'm aware of extra weight involved in additional batteries, but for now I'd like to do this mod with the extra marine battery in the van.

Another electrical/ power related question:
Is it possible to bypass the van's cd player power needs for speaker use? In other words, use a portable mp3 player connected to the speakers without electrical demands on the van's battery? Or would portable speakers a better bet?

[Dogpilot]

In terms of size, 40-60 Watt panels fit nicely on top and cost $200-350. A 60 watt panel gives out about ~ 3-5 amps in full direct sun. Usually they do not provide enough power to meed surge demands of many electrical items, so you need to run it to some kind of battery with them to provide surge or startup power demands. (amps=Watts/volts) An Apple Macbook Pro power supply is 75 watts as an example, with the older Powerbooks being 65 watt consumers and iBooks ringing in at 45 watts.

Hooking your mp3 player directly to the car speakers would produce a barely discernible sound. It would sound like the fairies were singing off in the distance. An mp3 player puts out a miniscule amount of power, enough for earbud headphones. All the portable speakers are amplified to accomodate this.
_________________
Geology with a Syncro rocks!
86 Syncro Westy AKA "The Bughunter"
98 Disco I
08 Range Rover SC
08 VW Rabbit S
1951 O-1G

[noganav]

I have been thinking about integrating a solar panel directly and permanently into the luggage rack (I've never used it for luggage) by cutting out the bottom, and mounting the panel inside so that it's flush with the top of the rack. Harder to steal this way, if anyone notices it up there at all. There are 85 watt panels that will fit perfectly in this application.

http://store.solar-electric.com/shulsoelpa.html

Instead of bypassing the stock CD player why not run it off of the battery that's getting power from your solar unit? You can get FM transmitters that will send signal from your mp3 player to the deck, I've got a Newertech roadtrip with a standard headphone jack so that I can run my mp3 player, laptop for movies, or portable record player when I want to keep it real. Unfortunately it looks like they don't sell the model with just the headphone jack anymore, but I'm sure someone does.

[RCWesty]

thanks for the info.
I've seen some new products that are foldable for easy storage (but high costs) that might not be so rigid during travel.

http://solarhome.org/index.asp?PageAction=VIEWPROD&ProdID=1124
keep from putting holes in the poptop. Folks at gowesty have one also, but a bit smaller.

considering the cost- benefit and other wiring issues, a quick search revealed
http://westfalia.org/eve/forums/a/tpc/f/39760455/m/9366067251

wonder if these issues are still a limiting factor?

[singlewc]

[Dogpilot]

You are defiantly correct in your summary of cost to benefit ratio. Solar, at its present pricing per watt is not economic. Personally, I didn't mount mine on the pop top for the reasons pointed out. I have salvaged a satellite dish mount, and I am in the process of modifying it to be a holder for the panel. It allows you to tilt it at the sun at the correct angle for that pure 90° sunlight. The best part of Satellite dish mounts, they are free. Somebody is always throwing one out. You just need to make four folding legs for the base.

One of the lessons I learned in Africa was use two panels. We would run our HF radio off solar and batteries. We used two 35 watt panels, one got more sun in the morning, and one in the afternoon. It kept the power pretty even
_________________
Geology with a Syncro rocks!
86 Syncro Westy AKA "The Bughunter"
98 Disco I
08 Range Rover SC
08 VW Rabbit S
1951 O-1G

[rocket j squirrel]

I like our solar rig. I have two BP Solar 35-watt panels that I keep stored where the upper bunk used to be (took it out because we need the space and never sleep up there anyway). The panels get placed out in the sun, braced upright with cheap camera monopods behind as third legs. I move them as needed to face the sun. I'd never put the panel atop the van because I prefer to park in the shade when it gets hot, and it gets hot a lot here in the southwest US.

The panels are wired to the van with 6-gauge marine wire, using Anderson Powerpole connectors (http://store.solar-electric.com/anhicupoco.html - me not associated). A Blue Sky 2000E solar controller (http://www.blueskyenergyinc.com/sb2000e.htm - not affiliated) constantly calculates how to load the panels to achieve the highest current possible for our Group 27 100Ah deep-cycle battery under the rear bench seat.

With this rig, we run a Norcold electric refrigerator, a laptop, watch a DVD (quietly) in the evening, and operate some low-power lighting at night. Under these conditions, the battery has never gone below 80% capacity (80aH remaining) by the time the sun hit the panels in the morning. By noontime, the battery is fully-charged again and we have "free power" all afternoon until the sun goes down. Wash, rinse, repeat. Calculate your Ah usage, get sufficient panels to provide it based on your latitude and expected hours per day of sunlight. Use fat wire between the panels and controller or you'll lose a lot of otherwise useful power in the wiring.

[singlewc]

[rocket j squirrel]

The fridge is a Norcold DC0400 mounted in place of the original Dometic. Our Dometic was a fine unit, and performed up to snuff, but simply wasn't capable of keeping our foods as cold as I'd like when the outside temps got over 90F. This Norcold draws 2.5 amps when running, which it does for some percentage of the day depending on ambient temp. During a very cold night, it seldom runs. If it's in the mid 80's during the day, it will run four to five minutes per ten minute period, or a 40 to 50 percent duty cycle. That translates to, say, 1.25 Ah during the day, and pretty much a lot lower at night. Per 24-hour period, call it 20Ah.

I've found that laptops generally pull 3 amps. I use a generic eBay 12-v laptop power supply (more efficient than converting 12vdc to 120vac w/ an inverter, then using the laptop's ac-to-dc power supply to take it back to DC). Say I run the laptop for two hours -- that's 6aH.

For lighting I have mounted two small dc fluorescent fixtures under the "spice rack," and one on the ceiling between the captain and passenger seats. I forget the brand/model but marine suppliers have choices. There are also a couple halogen "reading lights" mounted to shine on the rear bench seat. Each of the various lights draw an amp or so when running, but we don't do a lot of that - one light at a time, usually, and no lighting if we're watching a DVD (softly. Player wants 2.5A so a film might need 5Ah). Say we use 6Ah total in the evening for lighting.

So that's all less than 35Ah per day. Add some extra for maybe listening to soft music when it won't bother neighbors.

When charging, I read 6A+ on the controller flowing into the van from the panels when the sun first hits the panels in the morning. Our nighttime deficit is usually less than 20Ah because the refrigerator didn't need to run so much at night, and usually before noon the battery is fully-charged. The controller does a great job of slowly tapering the current into the battery as it comes up to my programmed setpoint of 14.2V. The controller holds the battery at 14.2V with a 0.8A trickle current once fully-charged.

I use a Xantrex battery monitor (http://www.xantrex.com/web/id/96/p/1/pt/7/product.asp) to monitor the battery's state of discharge.

During the warmest part of the day, the refrigerator runs more, but the panels are fully-capable of providing all the power needed to run everything. In fact, the battery never needs to output any current at all during this period -- once the battery is fully-charged, the controller keeps the constant trickle current into the battery, keeping it at 100%.

When the sun goes down, the relay in the controller clicks to indicate that the panels have gone offline, and the battery becomes the sole supporter of the van's power. As mentioned previously, the dusk-to-dawn power requirement is never more than 20Ah, leaving 80Ah in the battery by the time the sun hits the panels in the morning.

I hope this helps. I made an error in my OP, when I said the two panels were 35W units -- they are actually 45W units.

[singlewc]

[PDXWesty]

I use a 125 watt solar panel with two auxillary batteries with a total of about 120 amp hours of storage. One is under the drivers seat and one under the sink. I store the panel on the upper bunk between the pad and the roof. It fits nicely and I take it out when I need to use it. I prefer it not perminantly mounted.

I have a normal 120v type plug wired to my auxillary batteris and one on the solar panel outputs. I use polarized plugs to keep the positive and negative correct. This way I can use any typical extension cords between the panel and the van. If you're camping in the shade, you can place the panel in the sun somewhere. I actually hooked it up once with about 150' of extension cord and had it across a creek! It worked great because we were in the shade.

Last weekend I was camping and someone left my key in the ignition and the key on. When I woke in the morning the starter batter was dead and at 7.5 volts. Within 25 minutes with the solar panel connected I was able to start the van. That was well worth it!

Panels are expensive. This one is normally $600-$700 bucks. I got it for $100 because it was damaged but it functioned 100%.

Here's a picture. I move it to face the sun depending on where I'm camping.