Reward for lost Kraken!
Join Date: Apr 2006
Thanked 131 Times in 128 Posts
Rep Power: 11
Re: yet another battery charging question
Chal, if you have a problem with shade on the coachroof, I would suggest looking at 2-3 smaller panels instead of one larger panel. If you have one panel and any part of it is shaded, typically the output from the entire panel is degraded. If you have two smaller panels, you can lay them out on opposite sides of the coachroof, giving you greater odds that at least one will not be in shade, and will be at full power.
Sometimes one panel is made up with two or more distinct strings of cells in it, so that a shadow just reduces output and takes out one of those strings. You'd need to look into that with the maker, but I'd suggest 2-3 separate panels give you the best odds of keeping at least one out of the shade at any given time.
And beware of cheap "no name" MPPT controllers. In the US we've heard of some being sold that actually are not MPPT controllers at all, just hucksters capitalizing on the extra bucks they can get by calling them that. After all, who is going to open them up to find out?