Panels -
Right, China is making zillions of cells, they can't use them all so the worst ones are being dumped on the market to make cheap Solar Panels. The quality of these cells are poor, all the "A" grade cells are used by the manufacturer themselves, the "B" grade cells are then sold off to make panels of highly variable quality. To try and make it sound better, they have also introduced a panel quality rating, this is based on the visual appearance of the "B" grade cells when mounted into the panels, very little technical specification other than the most basic is provided so your basically relying on the marketing words of the salesman to go by - good luck!
Controllers -
There are two types the older style using Pulse Width Modulation (PWM) which are over stocked and sitting on shelves not being sold.
Then there are the Maximum Power Point Transfer type which are a lot more efficient, they cost more than the PWM.
Hence there is a race to sell the old PWM type to get them off the shelves, and again a lot of marketing words are used! Several types have suddenly been relabelled MPT or MPTT on EBAY and the like to try and confuse.
Mountings -
Unless designed for the job you run a serious risk of loosing a panel and causing a serious accident - two such reports from people on FaceBook see pictures I've saved here
http://www.g8dhe.net/bongo_images/Solar ... ot_to_fix/ the panels need BOLTING to the roof and the mounts need BOLTING to the panels, always use Nylock nuts to prevent vibration problems. Glueing as used in one of the pictures above can work BUT you need to use the right stuff and use it correctly on a CLEAN surface, otherwise another flying panel!
Despite similar warnings I have given on FB, people still go off and buy the cheap ones - first they find they don't fit the size of the roof - odd sized panels - the mountings use self tappers and the controllers aren't as "implied" and are actually PWM.
Yes they work sort of, but not efficiently in the UK sunlight and as reported two people have reported loosing panels, I wonder how many just stay stum on the matter!!!!
Go to a seller who relies on reputation to make sales, has done the work to make them fit Bongo's and will fit them for you if you don't have the skills. Despite having the skills I used
http://www.solarcampersolutions.co.uk/ to get all the parts in one hit, to know that it would work first time and if anything was of dubious quality I could return it easily! There are other suppliers as well of course.
If you have FB then read these reports;
https://www.facebook.com/groups/2529055 ... 961025733/
https://www.facebook.com/groups/2529055 ... 325080733/
https://www.facebook.com/groups/2529055 ... 756680733/
https://www.facebook.com/groups/7571714 ... 465934957/
https://www.facebook.com/groups/2529055 ... 670950733/
https://www.facebook.com/groups/2529055 ... 183785733/
Spherical Visions