Thinking I may have to make my own solar panels. Need advice

[3lud13]

So I am currently looking for solar panels for my truck but I am very limited with size and placement due to it being a canvas roof and I am wanting to install them on the underside of my roof cage. So the dimensions J have to work with are 410mmX850mm for the front ones and 410mmX920mm for the rear ones I can have 2 of each size giving me 4 panels in total sizes can't exceed those dimensions due to other tubing in the way.
Ideally I would like each panel to be a minimum of 50watt (this is only going by what I have been told by others to keep batteries charged and things running), I have been searching around and most commercial panels I have found meeting those dimensions are only 20watt.
I began searching ebay for solar cells with the idea I may be able to make some up without as much wasted space as the commercially available units and therefor get a better wattage what I have found is below.
http://www.ebay.com.au/itm/25pcs-6x6...4AAOSwECZUogOz6"X6"cell 4.3watts
http://www.ebay.com.au/itm/70W-DIY-S...4AAOxyGqZSXhmh6"X3"cell 1.9watts
So going by my measurements using just the 6"X6" cells I can get up to 51.6watts which is ok but I thought that wastes alot of space and if I can use the 6"X3" cells also I can increase the wattage to 63watts for the smaller panels and 66.8watts for the larger panels, which brings me to my first question is it possible to mix different sized cells in the same panel?

[Mike90250]

Welcome, and first, look here

http://www.solarpaneltalk.com/showthread.php?3526-DIY-Eva-solar-panel-build

for the fieldlines post on DIY.

2nd, no, mixing cell sizes will not work.

3rd, for some sort of mobile setup, on canvas, I don't think any DIY rig will work long term (+2 years) Vapor leaks will happen and moisture will eventually get in to ruin the cells.

You would be better off to buy the inefficient flexible/conformal panels and use them if you want more than 2 years of service

[Raul]

There are flexy narrow panels designed for boats with sunpower cells 20% up efficiency ; I think the smallest is 50w going to 80 , 100 and so on.

[3lud13]

There are flexy narrow panels designed for boats with sunpower cells 20% up efficiency ; I think the smallest is 50w going to 80 , 100 and so on.

Every flexible panel I have found with a decent wattage (more than 40watts) has a width of 540mm meaning will be hanging out in the openwith no suppoprt

[Raul]

I seen on Titan-energy uk they sell 50 w panel with sunpower cells and is 305x1100x3mm in size . It comes with 2 rows of 5" cells.

[RayO]

Any buyer's advice on flexible solar panels? Seems there is always a trade off. I'm thinking of getting a 20 watt for starters.

[solar pete]

Any buyer's advice on flexible solar panels? Seems there is always a trade off. I'm thinking of getting a 20 watt for starters.

Hi RayO basically the small cheap flexible panels I consider temporary panels as in I dont expect them to work for very long at all that being said I have never used them personally

[PNjunction]

Rayo - PowerFilm makes excellent thin-film panels. Foldable / rollable etc. They are the real deal, and you will pay for a real product, and not some junk seen at the camping stores. Note that their specs show 15v, but the real open-circuit voltage for these is typically 18-20v ocv.

Understand that since they are flexible, they are usually not mounted in a flat-plane perpendicular to the sun, so the output is less than stated for lab specs. (ie, laying flat on a roof, rocks, etc.). If you can get them perpendicular, so much the better.

Are you sure that 20w will actually do the job? That is only about 1.2A under best conditions during the solar insolation period. You may want to measure your actual power draw over time before investing in a quality thin film to make sure you get the right size, as quality with powerfilm is expensive.