Could you give a few more details about the setup? Number of
panels, type of
panels, parallel or series, etc? I assume from your numbers you have a parallel setup, perhaps with 4 200W panels?
I'd imagine you'll want something like a TriStar
MPPT 60A charge controller. Given 800w at 20v I'm coming up with 40 amps, but I assume you'll want some
headroom for exceptionally cold days when output is higher.
If it were me and I had the cash to spare on extra controllers, I would probably have individual charge controllers per panel. It sounds to me like you already have a bigger parallel setup wired, and in that case, I'd probably pick the TriStar TS-MPPT-60 which from my prior
research gets good
reviews.
I selected a Solbian 112Q panel with a Genasun GV-10 for our Quorning
Trimaran and we get around 7.8A @ 13.9V (108.42W) maximum on perfect days, but generally around 6.5A @ 13.9V (90.35W) on mostly sunny but not ideal days. This is enough to keep our 180AH bank topped off almost indefinitely in
Denmark during the summer, with our only real
consumption being a tiller based
Simrad autopilot, a 40W Waeco freezer/fridge, plotter, LED masthead tri-color light, and USB
charging port. We get down to around 70% of total bank after a full day and 4 hour evening under sail with the
autopilot and fridge on, and usually back up to 95-98% by the end of the day.
That said, I don't have too much experience with the size of setup you're describing, but I'm pretty sure you'll be stuck deciding between either one quality 60A controller such as the TriStar or splitting the panels either individually or into smaller groups for multiple smaller controllers.