SolarPanels on SprinterVan

[SolarSprinter]

I have a 2006 sprinter van, long wheel base, and would like to get at least one Solar Panel on it to keep a 12 volt. marine battery charged which I already have. The main purpose for this will be to run my heater fan and pump that burns diesel fuel(espar heater), a lap top computer,Crock pot and a light. I was thinking it would be best to get the largest most powerful for the space in case I would want to put more panels on in the future, particularly if it would be possible to run my AC off of them or get a new AC in the future, if they come out with a roof air conditioners that runs off of DC power
The width of my van is about 61 inches. and noticed some solar panels are about that in length. I have been considering evergreen solar being they are American made and would like to buy something made here.
Im just getting started and do not know about charge controllers,grounding wire and what ever else I need. I appreciate your help. Solar panels have been a interest of mine ever since President Carter encouraged their use in the late 70s.

[Mike90250]

Hi, and welcome.

Because of power, a single panel will run laptop, couple of LED lights, for a couple of hours. More panels and batterys, and you can add the heaters fan.

The Crock Pot and AC, just draw too much power, for too long, to be workable.

But - any of the many Solar Ovens for cooking, will work fine for crock pot meals (on sunny days) http://solarcooking.org/plans/

61 inches - the van roof is arched a bit, and the panels need to stay perfectly square and not bent or stressed. Will the panels be mounted at all times, while driving, or just deployed while parked?

Rules of Thumb:

Never drain batteries more than 50%

Recharge batteries within 24 hours

Equalize batteries once a month (flooded cell only)

Only add Distilled water (flooded cell only)

Panels flat on roof, only 50% of nameplate wattage

Charger system to be least 5% of your battery capacity (if 100
amp battery, needs at least 5A charge system, 10-15% is better.
(means for 100A battery YOU need a 12A panel, to make 5A.

Any panel, will only provide 80% of nameplate (panels are tested cold, when more efficient) and on your roof, run quite warm, loosing 20% !!

Look into a Honda EU1000 portable generator (or clone) for battery charging when no sun. eco throttle really saves fuel under light loads.

Consider the several models of the Black&Decker electronic battery chargers.
I have (and like) the 1093 model (Black& Decker bought Vector)

http://www.amazon.com/Vector-VEC1093-Smart-Battery-Charger/dp/B00009RB0T

Mike

[SolarSprinter]

Thanks Mike for your reply. I do not use a charge controller when charging my battery, I just hook it up to my battery charging connector on my Honda EU 2000 generator and put it on eco throttle. I hope this is okay and that I will not blow the battery up. Also If I have to, I will get someone to fabricate a battery rack underneath if I need more batteries.
Definitely I would like solar panels that are fixed permanently I am trying to eliminate work of having to cary my generator out every time I stop. My van roof starts its curve about 61"in width. Are you saying that if I put rectangular panels on my roof and let them hang over the sides a little without support on the ends that this will not work. I was even thinking about 65" panels.
Also for charging batteries do I need solar panel with high voltage output.
Elwyn

[Mike90250]

The battery charger @ 20amps, is more powerful than the generators 12V charge terminal, 40A would be suitable when you get more than 1 battery. (40A on a recurring basis will damage a 100A battery)

The panels need to be supported rigidly, and the 61" wide ones, likely need support at the middle of their short ends. Also, wind buffeting, if wind or suction is trapped between the panel and roof, you will blow the centers out, they are not made for 65MPH winds. I have a friend who put 8, Unisolar 64 panels on a converted bus, and they are fine, but those are plastic and stainless panels, made to flex.


PV panels ALWAYS MUST exceed the battery voltage, they are effectively "pumping uphill" to charge the battery. A 12V battery, needs about 15V to recharge. 2 Volts get lost in the charge controller, so the typical 12V battery charging panel is 17 - 19V max power. 25V open circuit.
You should use a charge controller. The Trace/Xantrex C-40 is a good beginning controller, you won't out grow it for a while.

[SolarSprinter]

The reason I was considering panels other than flexible thin film, is because I was thinking that panels put out more electricity for the space used. Do you know of any other companies that sell flexible thin film other than Unisolar. Can First Solar be purchased in this country. It will be strange if it cannot being that their headquarters are in Arizona.
Also does voltage double when you add the second panel of the same size and so on. And will the Battery charger that you recommend, does it have a charge controller built in.I know I need one when I get solar panels. Thanks for your advice.
Elwyn

[Mike90250]

You can wire panels in either series or parallel, increasing volts or amps. 2 or 3 panels, usually are wired in parallel to increase amps.

The Unisolar 64 is a rigid frame panel, but has a plastic cover, not glass, and the PV material is plated onto a stainless substrate. (aluminum now) It can flex and move some, without damage. It's not a roll of plastic.

The B&D 1093 battery charger, is a regular 120V battery charger. For your PV, you will need a charge controller (C-40)

[newenergy]

I put a solar panel on my truck to charge tool batteries. I hooked it up to a charge controller, which was only like $25, and then to a small 12V battery and connected the battery to a cigarette lighter charger and/or inverter. I have a lumber rack so I just mounted some unistrut on the rack and the module to it.

I also mounted a couple Evergreens on a friends boat using the same standoffs I would use for a house. I didn't do the wiring to the battery charging system though.

The Evergreens are 18V, which is good for charging the 12V batteries, with a charge controller.

It doesn't seem like it would be good to do this w/o a charge controller unless the panels put out exactly the 14.4 or w/e volts your battery gets charged to.

[SolarSprinter]

I defiantly do believe I need to get a charge controller and probably should invest in the one Mike was referring, because I will not have to upgrade when and if I get more panels. I am interested now in the Unisolar 144w flexible that all I will have to do is roll it on and stick it to the roof. either that are get a very rigid solar panel that will withstand the wind, because I often drive 70 MPH. to make my deliveries on time.
The draw back about solar panels that stick to the roof is that I do not know if I can get them off and transfer them to my next van when this one wears out.
Unisolar and Evergreen are both US Companies just wish there was much more Government Incentives for people to buy their products.
Elwyn

[russ]

I am not an authority on Unisolar but some people are very negative about their thin film type of panel pointing out very poor results and rapid output drop off.