That's one thing I worry about. at 15.4 is the inverter going to turn itself off? There goes my fridge and freezer.
<Speak of the devil. My system just went into “equalize” mode for the first time with the mppt controller. 16Volts for L16s. They are gurgling nicely thank you. Inverter went into OVP and the cottage lost power. Oh. by the end of the cycle they were fizzing every so slightly. neat.>
Temperatures must be okay as the fan rarely comes on. It's a 3000w pure sine (my load peaks 2000? - heater, stove fan and microwave run at once). I'm actually pretty impressed with the Ramsond. I know nothing about their reliability etc, but the inverter appears to be working well. I leave it on 24/7 and the 30 amp line runs my "cottage" nicely.
To the point:
I think Morningstar has some efficiency specs on running higher voltage into a lower voltage battery set up. See the manual p 61/62.
52 vmp to 48 is 99 and a bit efficient at my ideal 1600-2000 watts of solar input. 66 to 48 is 97.8 eff. 98 to 48 is 97.5. So there is some loss in controller efficiency. I would compare that to reduced line losses and copper savings, but I'm lazy.
When I look at the chart with my set up I’m well under 2% losses with my wire sizes).
The specs show me to be 95 efficient, drawing my 48 to 12.
I used 6 gauge from the panels to combiner box (8ft). And 2 from there (4ft) with 2/0 for the battery to the inverter (3ft). I wonder if I don’t loose more to connector loss ...
So: I can add 2 batteries and buy a new inverter at 24v for 1400 bucks. Allowing me to add two panels sitting in my trailer and go to 1500w (and increase eff. to 97.5).
Of course it's a simple battery connection to go to 48 (99% eff. @ 48v). But that's a 2600 upgrade with the inverter. I'm not sure I need that size system yet (of course, build it and the demand will come).
Beer fridge!
really should be working on my eco toilet, water system and shower ...
