Solar charging batteries

[precorguy]

I am camping for 4-5 days in Jul without hookups - which is fine as it is just me - so no need for major electric use - just want the fantastic fan, water pump, a couple of lights (seldom use only) and maybe the radio --- so i figure two 12V batteries should last me most of the time.

there will be lots of sun (camping in an open area - aka field) --- so i thought i would be good to use some of the free sun energy to recharge the batteries - i already have a 15w solar panel and a charge controller --- use it in the shed to charge the batteries for the yard stuff plus power some lights.

i need opinion on:

> given my past experience - i get a pretty good charge over the course of a day - so this should give me good charge of batteries for the weekend - right?

> how much power will an inverter strong enough to power the coffee maker (just to run a pot - no warming) - 1750 watt inverter - use - any ideas?


is there a good online source for information on solar power - just curious if anyone has come across one?

thanks

[pwb01]

I have dry camped many times with the two of us for 5 days using 2 batteries without any problem but being a little conservative on usage. I have two batteries on the frame and now I temporarily wire in a third for stays longer than 3 days which leaves us power to spare. We may even watch a movie at night on a 12v DVD player. Any inverter will drain your batteries very quickly running a 120v appliance with a heater with such high wattage. For coffee we've been using the Coleman drip coffee maker made for a gas burner and it works great. I think they're about $40 now. It's a little slower than an electric drip but 10 cups takes about 10 minutes, I can live with that.

[Steve Collins]

The built-in radio uses juice even when turned off. Better to pull the fuse and use a battery radio.

Same for the propane detector. That's a personal call, but with the strong captien (sp) that is in propane here, I'm OK with pulling that fuse, too.

Make sure the heater strip on your refrigerator is OFF. It will kill a battery fast.

We have the same coffee pot as Paul (pwb01). Love it. It is identical to the Mr. Coffee I have at home, so it's old familiar for me.

I went through the trailer and removed one of the 921 bulbs from every light fixture that has two of them. I then installed 194 bulbs. They are the same bulb as the marker lights on my Sunline, and are dimmer, but totally adequate for everything but reading. The brighter the bulb, the more drain on the battery.

On that subject, if the old budget permits, I am going to swap out all the interior bulbs for the LED versions - much lower consumption.

I also bought a three-pack of stick-on battery operated LED lights and put them in places that we'd most commonly want light late at night. No drain at all on the battery for a late night potty break... The even twist off their mounting plate so you can carry them as a flashlight.

If you think about it, there are many more ways to cut battery consumption when dry camping. We dry camp at least 5 weeks a year so it's second nature to us.

But I have a C-PAP machine now that uses 12vdc. We'll have to see how that affects battery drain. We've made do with a single battery for quite a few years, but the C-PAP may force the addition of a second battery.

Your little solar unit may well keep your whole rig nicely charged up for the entire weekend is you practice some conservation on the battery drain. Set it up as soon as you get there, and make sure it is not ever in the shade. I will be real interested to hear how that works out for you.

[Viking]

Steve,
Pardon my ignorance, but what and where is the "heater strip" on the fridge?
Roar

[Steve Collins]

Originally Posted by Viking

Steve,
Pardon my ignorance, but what and where is the "heater strip" on the fridge?
Roar

There is a heater strip on the horizontal face of the refrigerator body between the freezer and fridge doors. It is there to eliminate condensation by warming that panel. In doing so, it consumes a lot of the battery's charge.

On my Dometic Americana fridge, you have to open the freezer door and look up at the underside of the top horizontal door frame on the right. There is a rocker switch there that turns the heater strip on and off.

I don't know about other models, but if the switch isn't in that location on yours, check the manual as it should be there somewhere.

[Viking]

Thanks Steve!
Ours is a Norcold 462, and I found the description under
"High Humidity - Storage switch" described in the "Operating and User Instructions", which I had downloaded off the Net and printed out. Also shown in the wiring diagram.
Your information caused me to read something I had earlier skipped.
Even though I do not have a Sunline yet, I really like this forum. It is very educational.
Roar

[pwb01]

Here's another tip. As a motor starts it uses peak amperage then drops to a running amperage draw. When you run water the pump starts and stops many times drawing a lot of amperage at each start. I put in a 2 gal acumulator tank so now the water will run for about 30 seconds before the pump starts then runs steady until the tank is full again. This eliminates many of the starts drawing top amps. I also replaced many of the bulbs as Steve did.

[Honda03842]

A side benefit of the accumulator is that the pump rarely has to run during the night on bathroom visits.

As to a coffee pot, we have a four cup 600 watt pot. Considering that the coffee pot is not on very long, the power draw is minimal. A pair of light bulbs on for an hour draws more power than the coffee pot.

Lights are killers, LEDs can make a big difference. They are expensive but when you consider their cost compared to an extra battery or its supporting solar panel they are inexpensive.

Norm Milliard