It arrived

My new MPPT charge controller arrived today. Looking at it, I'm scratching my head as to where to put it. It's absolutely flaming massive. Needless to say I bought the 30A version when the 20A might have sufficed. What blew me away was the sheer size of it!

The thing is massive and has a humungous heatsink. It's supposed to max out at 400W of solar power. Well, all my panels combined add up to less than 200W right now, including the two that have yet to arrive. I still have to decide how I'm going to attack putting a new panel on the front of the bus. Two 10W panels gives me 5W more than before. My two 30W panels can still be set up inside the bus. My two 20W panels can still be set on the ground in direct sunlight. The two oddball panels - the "60W" that seems more like 10W and the 5W panel are more likely of use as solar demonstrators.

As can be seen in this picture, there's really not much real estate at the back for my new solar controller. Complicating the matter is that I have to be very careful about making new holes in the panel. I was dumb enough to inject spray foam into the cavity which has had the side effect of fixing into position the wires behind the panel that would otherwise just be brushed aside when I'm drilling or whatever. I had thought the new controller would be the same size as the existing controller.

Looking at the manual, I'm quite surprised that it gives me the same information (or lack of it) as my existing PWM solar controller. Clearly I'm going to have to connect the panels to the controller using SAE connectors so that I can put a watt meter in place occasionally. I'll do the same with the load side too as that way I'll be able to meter electricity usage more accurately when needed.

Already inside the bus I have some cheap digital Chinese volt meters and unsurprisingly, I can get different voltages displayed on each one - all in the same ball park but while one says 12.6v another will say 12.5 and another will say 12.7. There surely can't be that much voltage drop as the cables are all plenty thick enough for the current needed by those meters.

If I can't get the new controller to sit neatly in a vacant space, I'll have to move a few things around. That's more work than I wanted but if it'll achieve my goal then I'll do it. Part of the problem is the organic nature with which the system has grown.