Solar panel setup

TygerCub · 03-11-2012, 05:47 PM

This weekend Harbor Freight had a huge sale on most of their store. Their 45 Watt Solar Panel Kit was on sale for almost $100 off the normal price, so I picked up 2 of them. But while researching what else I might need to power the bus, I read several reviews on the HF page where people say the controller is unreliable. HF sells a 100 Watt Solar Charge Regulator, but several people said the wiring is a little wonky. I know little enough about these things that I'm afraid I'm going to fry something important.

Can anyone recommend a better alternative controller/regulator?
Would I need anything larger than 100 watts if my panels only add up to 90 watts?

And what about inverters? I want to run my LED lights, a radio, and a computer from a couple of gel cell batteries when boon-docked.
Would I need a pure sine wave inverter to protect the computer? If so, can anyone suggest one that's not HUGE, but would give me room to grow?
Are there special gel cell batteries that work best for this application?

I'm excited about using the panels, but electricity mystifies - and scares - me to no end.

bus-bro · 03-11-2012, 11:23 PM

I think you should use what you have. Panels with plastic frames don't last all that long, and the controller is probably the on-off type. Not the good stuff, but can make juice. Install it and see how it works. Buy several golf cart batteries, wire the thing up and see how it goes. You learn by doing, and you seem to do.

bus-bro · 03-12-2012, 12:03 AM

No to gel cell batts. You'd want agm's, but as the saying goes "you always destroy your first battery bank", that's why I recommended the (flooded) golf cart batteries. Best bang (i.e. amp-hour) for the buck. Just learn how to protect yourself, and the bus from the battery acid, etc.. As far as electricity, make sure the wires are fused for their proper maximum current limit. That's on the net.

Most computers don't need a sine wave inverter (motor loads and especially induction hobs like pure sine), it's a question of what you can afford to do. A complete solar/battery/inverter/charger system could easly cost $20,000. How many watts do you need to run your expected load? What kind of loads? I wanted a 2000 watt pure sine inverter/charger with all the bells and whistles. What I could afford was a 1000 watt modified sine wave inverter and a three-stage converter charger. One setup was $2000, the other was $200. Four golf cart batteries were about $300. The 000 awg cables I used were free.

The switchgear and bus bars another couple of hundred. A battery (cummulative amp-hour used) meter is highly recommended, $150. YMMV. It all depends on how deep your pockets are.

Diesel Dan · 03-12-2012, 12:09 PM

My rule of thumb for buying stuff at Harbor Freight is to only buy things that do not have electronics or many moving parts. Let's face it, there is a reason their stuff is so cheap. It's low quality. I buy things like hammers, work gloves, etc at HF. I do have several air tools I bought there, and they are all still working, but I bought an air compressor and battery charger there that both crapped out. Lesson learned. I've also been tempted by the HF solar panels, but... I dunno man, I don't like to buy anything there that costs more than $100.

cschlessman · 03-12-2012, 03:35 PM

Solar can drive you nuts if not done properly. I have been offgrid for 20+ years and have made every mistake possible. My advice is read read read, before you start bilding a solar system there is a online forum sponsered by Outback power systems that has a RV dedicated section. Figure your loads average and peak then ask questions. My bus build is solar powered as I intend to boondock 90% of the time. Right now I have 3500 watt inverter and 1800 watts of solar with a backup generator. Battery system is 795 amp hr Lead acid batteries. Good luck.

Chuck
Here is their address http://www.outbackpower.com/

lornaschinske · 03-12-2012, 05:29 PM

The Harbor Freight solar system is a good inexpensive way to try solar. Yes it is a little pricier than "other" solar outfits when you look at the per watt cost. many folks do not want to spend a couple thousand just to "try" solar. Solar is NOT for everyone. A Harbor Freight solar set up or two) plus a couple of deep cycle marine batteries makes a good intro to solar. I'm not that into baby siting a solar setup. I would rather stick with solar vents, solar landscape lights and build a coupl window mount solar air heaters. I will stick with a generator for our OTR power. For us, solar would have a very long "payback" because we simply have little need for it.

I have seen several folks o n various RV forums use the cheapie HF solar panels (one guy bought three sets) and used them for several years. Then he started upgrading his battery bank and controller before upgrading his panels. Along the way, he learned a great deal about solar and murdered a couple sets of cheap batteries. It's better to lean how to kill a cheap battery than an expensive one.

TygerCub · 03-12-2012, 08:58 PM

Thanks guys. This is definitely a huge learning curve for me.

I love the idea of solar, but while I've researched solar power and wind power sites (Mother Earth News is my favorite), they quite frankly leave me confused and feeling rather thick-headed. Maybe I'm too much of a 'show-me' person? Let me visually see how something is put together, then let me touch and do it myself, and I can usually pick up a skill very quickly.

Reading tech manuals.... not so much.

So... I think I'll go ahead and stick with an inexpensive power controller, inverter, and golf cart batteries. As I said before, all I want to do is run some house lights (all LEDs) and a computer. If I can keep my crank battery charged as well, then I'm even more happy. The window AC unit in the back will be run via the generator. My "refrigerator" will run strictly from shore power & I'll use a good cooler and block of ice while on the road.

cschlessman · 03-12-2012, 09:46 PM

Make sure you dont under charge your batteries, you need a minimum of 10% of your total amp hrs in solar panels. My experiance with HF is leave the electronics alone. You can buy some real good charge controllers for less then 50 bucks. But as always as you will.

Chuck

chev49 · 03-13-2012, 11:15 AM

I use HF electronics almost every day... in fact, i have 9 unopened free multimeters in the cabinet in the bus right now...

mightybus · 03-13-2012, 03:08 PM

Quote:

Originally Posted by chev49

I use HF electronics almost every day... in fact, i have 9 unopened free multimeters in the cabinet in the bus right now...

Yep to the free meters andor screwdriver sets and the 20% off coupons!
I give them out at Christmas and birthdays.

thommassey · 03-13-2012, 08:01 PM

Quote:

Originally Posted by mightybus

Quote:

Originally Posted by chev49

I use HF electronics almost every day... in fact, i have 9 unopened free multimeters in the cabinet in the bus right now...

Yep to the free meters andor screwdriver sets and the 20% off coupons!
I give them out at Christmas and birthdays.

Used to get "xtra"coupons for the freebies, don't forget the flashlights! ... they knew me by name

RavensOracle · 03-13-2012, 11:42 PM

I've been thinking of solar when we head out for boon-docking camping trips. But I am not a full-timer, just a weekender so the price of it can't be justified for me. Since I am in Kansas it seems more attractive as a $ per watt setup to go with wind power. But even then, I still have to set it up for just the weekend. If I was going out for longer treks, then it may be a better idea. But right now I'll just run the genny when I boondock or use independent solar lights rather than a whole solar setup. Solar garage lights are only around $30 and they will light up most of the bus for several hours each night.

Harbor freight is great source of cheap stuff. I just put in an order for 20 of the LED small work-lights.

http://www.harborfreight.com/27-led-...ght-67227.html

These little things are great and work as a backup to my solar or shore-power lighting. They also have a magnet and a fold-away hook so you can find somewhere to put them. I will give a handful away but the rest are getting stuffed away into all sorts of spaces. Either on the bus or in the cars. These things cam in real handy when I was working next to the bus to get the propane bottle changed on our lantern last week. The magnet allowed me to just slap the light on the bus. They only take 3 aaa batteries but last quite a while for the amount of light they put out.

chev49 · 03-14-2012, 11:24 AM

at 3.99.. they will be around 3 .20 ..... and you still get a free miltimeter also at HF..I would be buying one at a time... then checking out... then back in...

RavensOracle · 03-14-2012, 08:12 PM

I just got the order in today. I guess they are so popular someone from the post office had to open the package and help himself to 2 of them. I've already got 5 in the bus. One for each of us. And some of the others thrown in different toolboxes. I also put on in the one bay storage box that the bus has.

TygerCub · 03-14-2012, 08:36 PM

Those look interesting. Wonder if they could be pulled apart and wired directly into the bus' system?

RavensOracle · 03-14-2012, 08:54 PM

I've got a couple that I need to put new batteries in. Somehow they got turned on in the packaging. I'll get pics when I open them up to replace the batteries.

SeanF · 03-15-2012, 12:50 PM

FWIW I modified a AA-battery powered LED "press light" to run from the 12v system. First I measured the voltage that was being supplied via the 4 AA batteries, which was just over 5 volts. Then purchased a 5v voltage limiter from Radio Shack and soldered it to the + leg in the battery compartment of the light. Then soldered 12v+ to that, and 12v - to the neg leg. Even with my horrible soldering skills it has worked fine for a few years.

On the other hand I have a small(er) LED press light in the bathroom that I keep on batteries. It is only used intermittently so the batteries last a couple of months. In that case it's easier to just swap out rechargeables as needed.

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