Tested my new Solar Panel today

If tariffs will be introduced, panel prices will go up by what - 10 or 15%? Unless Chinese ramp up the production and lower the cost (not a problem, given over-supply of under-paid labor) and prices will drop again. And, from what I hear, they ramp it up all the time, with govt being ambition-choked and the country fuel-starved. Or the govt will subsidize solar production like it did before - and they did, BIG time - so prices will drop again.

I would be more concerned about adequate wattage (which 150W is likely not), safe install (considering your particular roof), and a controller that has both proper features and proper rating. 10A is barely enough for this panel. Should be 12A.

Isc of 9.17 on a 150w panel is fairly low-- "normal" might be more like 9.46, so I am suspecting your panel has a higher Voc. Some panels have near 23 instead of near 22, so their Iscs are lower.

You won't see more than the Isc of the panel except briefly with occasional cloud edge effect. Or if it is really cold out. Your controller will be ok.

Count on getting less than rated Isc amps when the panel is mounted flat, like on your roof, rather than tilted and aimed at the sun as when used as a portable panel. So the controller will have even more margin.

If the PWM controller ever went over 10 amps, it would not fry right away. It takes a fair time to heat up and eventually fry.

BFL13 wrote:
Isc of 9.17 on a 150w panel is fairly low-- "normal" might be more like 9.46, so I am suspecting your panel has a higher Voc. Some panels have near 23 instead of near 22, so their Iscs are lower.

You won't see more than the Isc of the panel except briefly with occasional cloud edge effect. Or if it is really cold out. Your controller will be ok.

Count on getting less than rated Isc amps when the panel is mounted flat, like on your roof, rather than tilted and aimed at the sun as when used as a portable panel. So the controller will have even more margin.

If the PWM controller ever went over 10 amps, it would not fry right away. It takes a fair time to heat up and eventually fry.

Thank you. This makes sense and when I had the panel flat it was putting out 5.75 or so...much better when pointed directly at the Sun. This was why I thought a 10 Amp would work initially.

The battery has to go under my bed so I want an AGM and I think it will be a 120 AH model. I use very little electricity on this vehicle unless I change my fridge to a home style and think the 150 Watt will keep up with usage especially combined with the alternator when driving.

Not enough capacity for that panel. If there’s even a chance of adding a second 150 watts, buy a controller rated for 30 amps otherwise 20 would be okay, but wire for 30 regardless.

Do not go 120v only fridge if you can help it. Stick with propane if going off grid. You become a total slave to the 120v fridge for how much solar you are getting, and how much battery you can fit to the rig for how many days with no solar before the fridge can't stay cold.

BTDT--no fun at all.---unless you also have a generator and a decent sized amps charger--which we didn't have in the TC. No room for that. :(

Lesson is--any size rig-- if you go off grid with a res fridge, have a generator and a decent charger, or suffer. Do not expect sunshine every day.

150W is very little. Especially if LP fridge has 12V thermostat.
And so is 120AH battery - very little, though very heavy. Get 2*100AH AGM in parallel, they will cycle shallow-er than a single 120AH and therefore will live longer.

For most people it makes sense getting as much solar wattage as possible. Unless you are in no-charging geographic area like BFL, where solar harvest can be so low that doubling the wattage won't change the picture.

A single 150 might be all that will fit on that Dodge van he has.

Not much room or weight allowance with that. What can be done, is tow a small cargo trailer. It has a tiny tongue weight, and it can take the weight of more batteries and can have a solar panel on its roof too. You can take along a Honda 2000 Gen and a decent battery charger, too.

You put a 2000W inverter in the cargo trailer with those batts, and just plug the van's shore power cord into the cargo trailer's 2000w inverter as your "shore power."

At least one of our members here does that, with good success.

EDIT-- Almot makes a good point. It is all about solar conditions. Here in summer, EG, a guy next to us in the campground had a 160w on his roof for the period from mid-April till end Sep. Very seldom had to run his gen the way they live.

Meanwhile, we used about twice the DC AH they did (We are such DC pigs! :) ) But had twice as much solar, so we also hardly ever needed to run our gen.

In winter, the solar would have been near useless here, so neither one of us could have kept going without a lot of generator/charger time.

I would have been no better off with my twice as much solar has he has. No sun means no sun on any amount of panel wattage.

Thanks for the comments, I appreciate them!

When buying a solar charge controller, make sure that you can set it for your particular type of battery. Some of the cheaper controllers have minimum setting capabilities or offer only a single float voltage.

He mentioned possible compressor fridge. I've been toying with this idea for a while before discarding the idea, and found an OZ discussion where they did exactly this - in small vans like Dodge. Those were not very big fridges, under 6 cu.ft. It can get cold there in the night, but there is plenty of sun all year round. Despite all the sun, and alternator help, and "boosters" available in some fridges that accumulates the cold while on alternator, - they still had solar up to 180-200W. Installing more was not possible, and nobody regretted installing as much as they could.

Don't remember about their batteries, but 120AH sounds very little to me. And - heavy. My 100AH AGM are heavy, 120AH must be painfully heavy if you have to move them. Get 2*100 or 2*80. You're buying it for at least 3-5 years.