First-time solar panel user

[braeworth]

Hi everyone!

We ordered the optional 160-watt solar panel for our 2015 Leisure Travel Van Unity 24MB. We'll get the unit next Monday, after a 7-month wait. :B

We've never had solar power before. The rig comes with dual 6-volt coach batteries, a converter-power c/w battery charger (55 amps) and
a 600-watt inverter.

The question, if it can be this easily answered: what difference will this solar panel make in our everyday functioning? Assuming we have reasonable daily sun (our winter base is Arizona), what will the panel enable us to do that we couldn't otherwise do?

Hope this isn't too stupid a question 🙂 I'm good at some things, but electrical things aren't among them!

Many thanks, as always.

braeworth

[Almot]

It's become way too technical for the OP now that BFL has saddled his favorite tilted horse 🙂

What Don and SMK said:

Between the trips it will keep batteries topped up while in offgrid storage, thus extending their life. Not worth spending a grand or two, given the cost of 6V batts. Hardly worth spending, if your rig is on 120V maintenance grid while in storage either.

On an offgrid trips in AZ in winter it might let you camp without ever running a generator, though with a lot of conservation efforts, which includes optimizing and replacing some of your trailer devices. Some people can live on 40 AH a day. Some need 140.

On camps with hookups - can't say. I avoid camps with hookups unless camp is not too crowded and price is not too high, which doesn't usually happen.

[BFL13]

In the sunny half of the year north of 24N, daylight is longer going farther north but the sun is lower. I think this means the optimum tilt for a south facing panel would be lower to get more out of those longer shoulder hours, but I haven't checked Macslab for the actuals on that.

You can't just say being in Arizona in the winter is the same as being in BC in the summer even if the sun is the same altitude, because the daylight times are shorter in winter even in Arizona.

[RJsfishin]

Ray, if you ever had a portable panel, tracking the sun's arc all thru the day, you wouldn't be asking. BLF did a good job explaining it. My mistake to you was stating a %'age, which in reality is impossible to do, except under a given circumstance.
Common sense says that a flat panel w/ sun directly overhead, has nothing to gain. It also says that a flat panel w/ the sun's arc very low in the southern sky, has a whole bunch to gain. When we are talking "tilting" and "pointing" as BLF described it, there can be a 50% (maybe more) difference at some times in a day.

I had 200 watts portable on a sun arc tracking system in AZ last year,
I saw more than 50% difference at times,...whenever I would check.

This year I'll have 300 watts roof mounted, tilted to the south (adjustable)
I'm hoping the extra 100 watts will make up for the approx. 30% loss difference from sun arc tracking, to "flat/tilted"

Try it, you'll like it 🙂

Crazy Ray wrote:
Rich can you give the Facts about getting 1/2 amps by putting your panels flat on your MH. thanks. I would believe 5%

[BFL13]

Crazy Ray wrote:
Rich can you give the Facts about getting 1/2 amps by putting your panels flat on your MH. thanks. I would believe 5%

The increase from tilting varies with your latitude and time of year. When the sun is high anyway from those two factors, there is not much advantage over flat, but when the sun is lower from either factor there is more advantage.

At 49.3N in May, with my 130w panel on a sunny day I got 56AH a day in a test with it flat, and 70 AH a day tilted up 25 degrees same conditions. (Test was with a load running so the batteries stayed thirsty all day in order to get an all-day measurement)

Whatever your latitude, as the sun goes up and back down daily, you get an advantage from tilting if you are also pointing the panel. The tilt needs to be higher earlier and later in the day than at mid-day when tracking.

OTOH with a panel fixed pointing South, the proper tilt for mid day will be too high for earlier and later, with the sun not being able to see the panel so well from off to the side, so the trick is to use a lower tilt all day as an "optimum" compromise to get the highest AH haul for the whole day. Macslab has website on this optimum tilting for fixed panels.

[braeworth]

Great info and tips, friends! Many thanks!

That's why I love this forum ... awesome people! :B

braeworth

[2oldman]

160w solar is a 10-amp charger running roughly 5 hours/day, tapering off later. That's about 60ah. So you can use about 60ah/day on sunny days. If your TV is 10ah, that's 6 hours of TV. Your batteries will not charge if you're drawing that power.

X2 on Voodoo. Of no value if you're in a CG.

[Crazy_Ray]

Rich can you give the Facts about getting 1/2 amps by putting your panels flat on your MH. thanks. I would believe 5%

[ed6713]

It will open up a whole new world of boondocking. AZ is loaded with wonderful places you can camp for free. Nice NF campgrounds that typically have no utilities of any type. Thousands of square miles of desert areas just waiting for you.
Solar is the best improvement we've ever made to our Class C. In 2013, we spent a grand total of three nights in a commercial campground.

If you're ready to get away from the KOA routine, you'll love your solar.

On the other hand, if you are really attached to your campground pedestal, you've just wasted a few grand.

Enjoy

[pianotuna]

Hi,

If you pay for power at your campsites it can reduce the cost to you.

It will keep the battery bank in tip top shape between trips.

Each trip will likely start with the battery bank totally charged to 100%

Likely battery life will be extended.

[RJsfishin]

It will let you watch a lot of tv power free.
But if mounted flat on the roof, it will put out only about 1/2 the amp hrs, than if it was tilted toward the sun, and better yet, repositioned toward the sun at least twice during the day.

[time2roll]

Your battery will tend to stay full much longer. With conservation the battery will be full every day. With more use you can still run it down. Battery will stay tip top 100% charged between trips and probably last longer for it.

[1492]

Moved from Technology Corner

[voodoo101]

It is really only beneficial when you are off the power grid. When camping without power hook-up. It will charge your batteries. When hooked to shore power it is of no real benefit. And the inverter will let you have 110 electric to run a tv or other small appliance off the batteries when off the grid.