Question on Solar Power

[Ductape_Dave]

I am considering installing the solar power kit from harbor freight 45 watt, 3 panel with charge controller. My question is, can I use the coach battery power while the solar power is charging the batteries? I wasn't sure if the charging voltage would affect the house side of the batteries during usage.

Thanks for your responses!
Dave

[Unyalli]

Check out these kits for some usefull power with free shipping.
Solar Blvd

-Jeff

[consumeratlarge]

Those HF panels are good for 'carry out' battery chargers, (15w each) just put a charge controller on them and set them on top of a truck, tractor, or whatever. They have a nice molded edge on the ones that I have. But for solar power on the rv, and my remote camp, I bought at least 150w panels and MPPT controllers.

I use two of them to keep a bulldozer 24v system ready to go. If they get smashed on top of the ROPS canopy by a branch, they are cheap to replace, about $45 locally, ($145 for 3 on sale). They are a little bit of overkill for just maintaining batteries, but they will run a 12v attic fan pretty fast in direct sun, with no controller, and bring up a low battery at 1.2 amps/hour. They come with a very weird controller that is better than nothing, but I use the little Morningstar outdoor controllers, so they can just be left out in the weather.

But, you guys are right about not being enough for the RV system.

[hmknightnc]

Hey Dave

Yes you can use all the systems at once. However the HB 45 watt system is not the best choice. It is way too small for anything other other than a battery maintainer for an RV and it is extremely expensive on a $/watt basis compared to much more appropriate systems. I have 265 watts with controller (name brand) for about the price of your 45 watt HF system

[Golden_HVAC]

Hi,

Yes you can. However 45 watts is not nearly as much power as your RV is using each day. My motorhome has a E-meter installed in it. While the CO and propane detectors are on, it is drawing 0.8 amps per hour, and when the refrigerator is on, then a total of 1.2 amps per hour, or roughly 35 amp hours per day, or about what one of my pair of 120 watt solar panels can put out daily.

Check out this website, and look for a 12 volt "Nominal" solar panel. It will have a 20 volt open circuit voltage, and that is enough to charge a 12 volt battery at about 14 volts (while charging). SunElec.com

I am not saying that Harbor Freight price is bad, but SunElec.com sells 100 watt panels for about $80 to $120, depending on the brand. You will also need a solar controller, a PWM can use 12 volt nominal panels and works great at a much lower price than a MPPT controller.

You should also consider mounting it on the roof all the time. I used 6" long 2" angle aluminum from Home Depot, and then drill a 5/16" hole for a 1/4-20 bolt into the panel and 3 holes 3/16" for #10 screws into the rubber roof. Using sticky rubber roof adhesive, it will seal the aluminum to the roof and it will both not leak and that large surface area will keep it stuck to the roof.

I ran the #10 wires down the back of my refrigerator with the help of a metal coat hanger. Then to the controller, then to the battery. You can use the battery while charging, just like when plugged into shore power. You can also plug into shore power or not, depending on your needs. It will not matter to have both charging at the same time. Just if you are at a campground plugged in, your solar will probably shut off if the battery is full, and don't worry about that.

Fred.

[pianotuna]

Hi Dave,

Yes you can, but the Harbor Freight kit is a POOR choice and extremely expensive per watt.

[Mandalay_Parr]

You can use everything. No problem.