PV Gap

Alexander Said:

would a 10w solar panel charge my deep cycle camper battery. if not what would?

We Answered:

The answer depends on what is using power from the battery. How fast is the battery drained? There are RV kits that have 10W panels in it, but they will basically keep the battery topped off (batteries self-drain when sitting around), and could probably handle a low power light or two. http://www.altestore.com/store/Kits-and-…

If you want to be able to power more of your devices in the camper, use the calculator here to determine what size solar panel you need. http://www.carmanah.com/calculators/mobi… Then you can go here to find a kit that will meet your needs. http://www.altestore.com/store/Kits-and-…

Bruce Said:

Can I connect 2 solar panels in parallel if they have different Open Circuit voltage ( e.g 22V and 14V)?

We Answered:

Likely you can not connect them in parallel and may risk damage if you do. Consider the analogy between electric current and water flow. Voltage is equivalent to water pressure and electric current is equivalent to water flow rate. If you connect two tall water towers in parallel, water will flow from the taller tower (higher voltage) into the lower tower (lower voltage). You will likely drive electric current the wrong way through the 14V unit perhaps causing resistance heating and damage.

Rebecca Said:

will a motor with the spec of 5 Amps run if you supply only 1 Amp?

We Answered:

your power power per cell is 17.6 V * 0.57 A = 10 W

so going in paralle makes sense.

Depends on fan specs - risk is it is a low watt fan and wires get too hot.
So without knowing the ratings it would be irresponsible of me to say go for it.

OK I rearead ? motor is 5A and 12 V so fan "expects" 60 W - so you should be fine - better to undersize than oversize for fire risk

Do what you propose - it should move fan and for the first day and first real sunny day really feel the fan temperature and see if it is too hot or not.

Lisa Said:

Please help . . . . . . . . . . . . 10 points ?

We Answered:

I'll make a few rather generous assumptions since you haven't provided details.

Assuming a 12 volt battery that has a charging efficiency of 65%, a panel that is optimally positioned so that it will produce full rated output for 12 hours a day, perfect weather, a charge controller that maximizes the power tranfer to the battery, no losses in the wiring, and no load on the battery during the charging period, it will take a little over a month to charge your battery.

You will have collected about 2 1/2 KWH of energy worth perhaps 25 cents to a dollar depending on rates in your area.

Don

Vivian Said:

AC fan will work with DC or not? What type of fan should i use?

We Answered:

I think you have more power than you need for a dog house vent. Unless you have an electric or electronic surplus store near you, your best bet would be to put two 12-volt computer fans in series. Computer fans readily run at lower voltages, and if you had 18 volts across them, that would be 9 volts across each one, and fine. Or put about a 2 watt, 15-ohm resistor in series with one fan.

A couple other notes. Just one of your panels is about the size often used in solar attic fans. The one we have on our roof is rated at 2 to 36 volts, an amazingly wide range. Remember, such fans are intended to vent the attic for an entire house, or a substantial portion thereof.

Finally, while it is true that AC is different from DC, most AC motors will run from DC. Synchronous motors like those in clocks will not, but inductive motors will. So if you had a room fan rated for 120 VAC, you could probably run it off DC, although you would generally lower the voltage to perhaps 80 volts DC to do it. No manufacturer would guarantee that it works or would be safe though, and neither do I.