prefer shade

[John61CT]

I like to park under the tree canopy if it's available, plus would like more panel square footage than my roof supports, plus I do use my roof rack.

Anyone seen setups with those ultra thin flexible panels can get relocated away from the vehicle?

Enough in series, or DC conversion would reduce the need for heavy gauge wire?

Be nice to move the DC genset out too, so spreads the extra wire costs out. . .

 

[John61CT]

That suitcase-sized portable "solar generator" idea seems just the ticket, especially with a 5x more weight-efficient LiFePO4 bank. If there's a larger lead "mothership" bank as well, can use the "battery-to-battery" DC charger to top the lead up from the lithium.

The latter doesn't need to sit at 100% for longevity like lead does, in fact apparently prefers 40-60% when not cycling.

B2B charger also used to "echo charge" the expensive lithium bank when the Alt's running, you do NOT want high voltage charges hitting it, shortens its life a lot.

Also have to keep the LiFePO4 from extreme cold, storage is OK but never charge them cold.

 

[akrvbob]

There are advantages to having your panels outside, mainly they can be pointed and tilted and you can park the rig in the shade.

But the disadvantages are large as well. 1) Pain in the butt factor of going in and out 2) during extended taveling you can't use them and can't put them in and out. 3) risk of theft 4) I personally doubt you are regularly going to get a long enough cord to actually park in the shade, wiping out their main advantage.

The jury is still out on the flexible panels, at this point I would not buy one.

 

[John61CT]

Here's a DIY on a "solar generator" ​http://www.gad.net/Blog/2015/10/17/the-yellow-box-of-power/

 

[jimindenver]

I have used big portables for 5 years. Bob is spot on as far as the advantages and disadvantages.

 

[John61CT]

I'm not claiming the Con issues aren't there, just that they may be worth dealing with for some, not deal-breakers for everyone.

My thinking is that keeping the LiFePO4 with the panels is what eliminates the need for any long cables or convoluted voltage conversion (#4).

In locations where I'm afraid of theft (#3) we're likely either in a park with shore power, or stealthing it.

#2 is an issue for me regardless given the roof rack's likely to be full of cargo

Unless I be the pioneer (arrows in the back and all) with flexi panels. Haven't they got cell stickers or little tiles yet?

Back in the 80's we thought integral to car paneling, or even PV paint would be a thing by now (darn Big Oil!).

wrt inconvenience (#1), for me just NBD. If it were, given what I need to go through every day cooking good meals for the kids, keeping up with our bathing & laundry, not to mention home-schooling, I reckon we'd just stay in the bricks 'n sticks.

 

[jimindenver]

Like I said I have used them for 5 years and if anyone has seen the tan Expedition with a solar panel on top, that is my very first portable. I use it to augment my roof top system. I also loan it out to those that need a charge from time to time. It has a 50 ft set of cords but even then shading can be hard to avoid. It will add another 5 amps tracking in the overcast conditions we have right now.

 

[John61CT]

Like I said I have used them for 5 years and if anyone has seen the tan Expedition with a solar panel on top, that is my very first portable. I use it to augment my roof top system. I also loan it out to those that need a charge from time to time. It has a 50 ft set of cords but even then shading can be hard to avoid. It will add another 5 amps tracking in the overcast conditions we have right now.

Sorry if I'm not clear, I think you are talking about the panels having 50' of wire back to a battery in your van?

The idea I've put out here, from post #2 on anyway, is a self-contained setup, "portable as possible bank in a box" like what they call "solar generators", with the controller and batteries kept located out there right close to the panels.

Along these lines:

If I misunderstood, then what is the long wire for? that's one issue I'm looking at eliminating.

Don't you find you lose a lot of the current? Or you talking a super-heavy bundle to lug around? Or are you stepping up to 36 or 48 volt?

Also when you say "tan Expedition" is that a model/brand of vehicle, or solar equipment or do you just mean it generically as in overlanding? Sorry for my ignorance on the automotive side. . .

 

[jimindenver]

I run two 50 ft 10 gauge wires back to the controller near the battery in the trailer. that is where I use my power. Since I use higher voltage panels there isn't any voltage loss as were I using the same watts in a 12 volt panel. That way I don't have to lug the controller and battery out to the panels and then back again to use the power, or also take a inverter out and run a 120v extension cord back.

I have a tan Ford Expedition and it has a 230w panel strapped to the top. Tracking the sun the 230w panel/ controller produces a average of 15a at 12v. The 435w panel I am replace=ing it with will produce 30 amps at 12v once I find a controller for it.

 

[John61CT]

Aha, getting clearer, hadn't heard about high-voltage solar, nor that model Ford, thanks for clarifying.