Too many panels (on a minivan)? Is my plan dangerous? Backstory and XINPUGUANG 100Watt 12Volt Monocrystalline _lightweight!_ question.

[NPhil]

(I'm compiling and editing down several comments from the NewPowa thread, hope that's OK)

I have four 100W NewPowa NPA100S-12H panels (now out of stock, evidently), which I have been testing, now and then, for a while. I've not mounted panels yet, but, during about a year-and-a-half of study, purchasing, and tinkering I've come as far as acquiring batteries, a Tracer AN 20A charge controller, an inverter, and assorted other necessities, and making dozens of tests with a pair of the panels, in series, charging a 24V battery. It's working well enough, in San Jose, CA, angled approximately correctly and pointed pretty near due south), to make enough hot water with an electric kettle for a pot of tea, many mornings, with a cup of Ramen for lunch and another pot of tea, when I am so inclined, with two of the panels charging a test battery which is a little too small (7S4P Tesla 2170 cells). As far as I know, the NewPowas are OK. In San Jose, I have never seen them produce more than 85W each, but that is I think good enough for me, and they will fit on my (mini) cargo van. Over time, my plan evolved from 4 panels, to 8, then to 12.

I've just tested on a rainy day and made only 1 pot of tea = 160 WH, plus inverter losses, and some other losses from recharging a 12V backup battery through a DC to DC converter (because the 7S4P test pack sags badly running an 1100W electric kettle, my inverter shuts down at 20.2V, so the pack can't boil a full thermos carafe of hot water without some help, the panels weren't putting out enough, on a cloudy morning, to do that as quickly as I preferred, and I wanted to test 12V to 24V and 24V to 12V charging anyway), I guess around 175 WH total, out of 518 WH (specified) in the pack.

So I think it will scale, to 1200W (really more like 1050, because I've never seen more than 85W from these panels here) from 12 panels (only 4 making power on the road, but 12 when the minivan is stopped and the panels un-stacked), into a 40A Epever Tracer AN, charging around 1.8 KWH of battery pack to start (I can add more later, if the money doesn't run out), delivering 6 Thermos carafes of tea (TCoT might become my standard unit) on a cloudy day.

Maybe 7 TCoT if I really got 100W, but I would have to buy a 50A Epever, which is a bit of a jump in price.

So I'm cutting it fine in a lot of ways, and there is one more- I just got around to adding the weight, and it's easily over 225 lbs (there are assorted aluminum shapes included).

This morning I learned, courtesy of Amazon "AI", of another panel possibility: https://www.amazon.com/dp/B08ML4V8GQ/

I am not eager to change brands, but, I am enticed by the light weight of these, eh, newcomers, because 225 lbs., seems a lot for the roof of a minivan. I have a cargo van, so I can find the strong points easily, and I just learned that a Transit full size is said, by the Ford sales dept., to carry 420 lbs. up there (although there is, apparently, a treatise somewhere on center of gravity which I have not read, but, maybe that will work out, since I will carry batteries, and other heavy things, low), so, by extrapolation, I should be good for 275 or so. But I might be pushing the limit.

These new panels, apparently, could shave off something like 85 lbs. from my 12 panel stack, and, they are thinner, which helps too. Sadly, they don't appear to match extremely well electrically with my existing panels, but, 85 extra lbs. is a lot to carry on the roof of a minivan.

Anyone think I should take a chance on a couple of them, to see what they are? My budget is somewhat limited.

 

[MisterSandals]

My budget is somewhat limited.

Have you considered big cheap panels instead of 4 little expensive ones?
Check craigslist in your area (or tell us your zip code and i will look). Its pretty
easy to get panels in the $.50/watt range.

 

[NPhil]

Have you considered big cheap panels instead of 4 little expensive ones?
Check craigslist in your area (or tell us your zip code and i will look). Its pretty
easy to get panels in the $.50/watt range.

I did. But, when I started accumulating parts, the NewPowa NPA100S-12H were the cheaper option, and once I had them, the design tended to build on what I was standing around staring at. After tinkering and testing, for over a year, I appreciate that they do have advantages. Spares are cheaper and more easily stored, for one thing.

 

[NPhil]

(I'm compiling and editing down several comments from the NewPowa thread, hope that's OK)

I have four 100W NewPowa NPA100S-12H panels (now out of stock, evidently), which I have been testing, now and then, for a while. I've not mounted panels yet, but, during about a year-and-a-half of study, purchasing, and tinkering I've come as far as acquiring batteries, a Tracer AN 20A charge controller, an inverter, and assorted other necessities, and making dozens of tests with a pair of the panels, in series, charging a 24V battery. It's working well enough, in San Jose, CA, angled approximately correctly and pointed pretty near due south), to make enough hot water with an electric kettle for a pot of tea, many mornings, with a cup of Ramen for lunch and another pot of tea, when I am so inclined, with two of the panels charging a test battery which is a little too small (7S4P Tesla 2170 cells). As far as I know, the NewPowas are OK. In San Jose, I have never seen them produce more than 85W each, but that is I think good enough for me, and they will fit on my (mini) cargo van. Over time, my plan evolved from 4 panels, to 8, then to 12.

I've just tested on a rainy day and made only 1 pot of tea = 160 WH, plus inverter losses, and some other losses from recharging a 12V backup battery through a DC to DC converter (because the 7S4P test pack sags badly running an 1100W electric kettle, my inverter shuts down at 20.2V, so the pack can't boil a full thermos carafe of hot water without some help, the panels weren't putting out enough, on a cloudy morning, to do that as quickly as I preferred, and I wanted to test 12V to 24V and 24V to 12V charging anyway), I guess around 175 WH total, out of 518 WH (specified) in the pack.

So I think it will scale, to 1200W (really more like 1050, because I've never seen more than 85W from these panels here) from 12 panels (only 4 making power on the road, but 12 when the minivan is stopped and the panels un-stacked), into a 40A Epever Tracer AN, charging around 1.8 KWH of battery pack to start (I can add more later, if the money doesn't run out), delivering 6 Thermos carafes of tea (TCoT might become my standard unit) on a cloudy day.

Maybe 7 TCoT if I really got 100W, but I would have to buy a 50A Epever, which is a bit of a jump in price.

So I'm cutting it fine in a lot of ways, and there is one more- I just got around to adding the weight, and it's easily over 225 lbs (there are assorted aluminum shapes included).

This morning I learned, courtesy of Amazon "AI", of another panel possibility: https://www.amazon.com/dp/B08ML4V8GQ/

I am not eager to change brands, but, I am enticed by the light weight of these, eh, newcomers, because 225 lbs., seems a lot for the roof of a minivan. I have a cargo van, so I can find the strong points easily, and I just learned that a Transit full size is said, by the Ford sales dept., to carry 420 lbs. up there (although there is, apparently, a treatise somewhere on center of gravity which I have not read, but, maybe that will work out, since I will carry batteries, and other heavy things, low), so, by extrapolation, I should be good for 275 or so. But I might be pushing the limit.

These new panels, apparently, could shave off something like 85 lbs. from my 12 panel stack, and, they are thinner, which helps too. Sadly, they don't appear to match extremely well electrically with my existing panels, but, 85 extra lbs. is a lot to carry on the roof of a minivan.

Anyone think I should take a chance on a couple of them, to see what they are? My budget is somewhat limited.

I Ordered two of the : https://www.amazon.com/dp/B08ML4V8GQ/ even thought there are still no ratings, or comments, because this looks like the perfect panel for my application.

 

[OnTheRoadAgain]

I Ordered two of the : https://www.amazon.com/dp/B08ML4V8GQ/ even thought there are still no ratings, or comments, because this looks like the perfect panel for my application.

Ha!
those are the same panels I'm using on my minivan.
MightMax sells the same panel under their name brand.

That's about $7.00 cheaper per panel than I paid.

 

[NPhil]

Ha!
those are the same panels I'm using on my minivan.
MightMax sells the same panel under their name brand.

That's about $7.00 cheaper per panel than I paid.

So, how are they holding up? Do they rattle in the wind when you drive down the freeway, or give you any other such cause to wonder about their long term durability? Are they more floppy than panels which weigh twice as much when handled (I'm assuming they are in reality as light as claimed)?

The panels were listed at about $90 when I first saw them on Amazon, a few days ago.

 

[OnTheRoadAgain]

So, how are they holding up? Do they rattle in the wind when you drive down the freeway, or give you any other such cause to wonder about their long term durability? Are they more floppy than panels which weigh twice as much when handled (I'm assuming they are in reality as light as claimed)?

The panels were listed at about $90 when I first saw them on Amazon, a few days ago.

Rock Solid. Like they're not even there. And I just took them on a 1600 mile road trip. Not one problem.
The panels are good. I would buy them again. I check the Voc, Max Amps and resistance. All good.
No add on rails....no modifications to the vehicle at all. Just fabricated some steel brackets to clamp them around the existing luggage rack rails.
They would also be VERY hard to steal the way the brackets work. Too thick to cut and bad angle for hacksaw.
If they have a Ziss wheel or plasma cutter, different story. Might add one more up front. Not sure. That one would require modifications.

 

[fratermus]

those are the same panels I'm using on my minivan.

Have you posted pics of how the panels are mounted on your minivan?