Well that's nice, I just checked the graphs and noticed that the batteries in the garage haven't been charging properly yesterday or today. I'm assuming it's the cold limiting them to 800W. I spotted the IHD showing we were exporting 3+ kW around midday and was surprised the batteries were full, but checking the inverter app showed they were only up to 30-something percent and were only charging at 800W - the rest of the juice coming from the panels was going out to the grid. So I dug a fan heater out of the spare room and put it in the garage, pointing towards the batteries, to see if that would help. Turns out the batteries warmed up enough to increase charge rate to about 2.25kW about 20 minutes *before* I turned the fan on, but I left it on for an hour to see how long it would take to bring the garage up to the heater's "frost protection" point. After an hour it still hadn't, so I've turned the fan heater off - it can't be set to any lower temperature so it's probably counterproductive. I'll just have to live with the batteries being a bit useless over winter. Should have gone for the ones with heaters built in. In fact, the installers probably should have suggested them when I asked for the batteries to go in a garage. Oh well, not much I can do about it now. Selling these ones second hand and buying batteries with built-in heaters would be just a bit costly, I suspect. Hmm. I could build a little insulated box around them and just heat that, I suppose. Removable so it could be lifted away from the batteries after winter so they don't overheat. Hmmmm.