One key thing to remember is that you will be cycling lead acid a lot and they don't like that even with deep cycle. We've had a couple of systems. The first we built over time on our 5th wheel with 5 x 55W 12V panels, charge controller, cheapy inverter for the TV. We then upgraded to a Magnum 2800W inverter/charger. This let us run our microwave and charge our batteries quickly. Our AGM batteries would be good for about a year and cycle out. We would have around 400AH of batteries. With the panels flat we get around 12A charge.
What we have on our conversion now are 2 x 300W panels, 400AH of LiFePO4, BMS for the batter Morning star charge controller for the panels, Magnum inverter/charger upgraded for CC/CV, combiner, 30A lead acid charger connected to the starting batteries and a bunch of misc. bits to connect and disconnect the LiFePO4 from the starting lead acid.
This let's us keep plugged into 15A and run everything. When plugged into 50A/generator then nothing runs of the batteries except lights and heater. On 15A all of the 110V stuff except for fridge and AC runs off the inverter. We get around 24A off the solar panels. So it seems we get around 1/2 the watts of the panels. Over night leaving the inverter on draws a far amount of power. DirecTV etc. draws power when off and then we have internet phone etc. So we turn off the inverter before we go to bed after watching TV. The generater is tied to the starting batteries so we don't have to worry about weak house batteries. An issue with the 5th wheel. We do a lot of dry camping.
The LiFePO4 work well. We haven't had cycling issues. We had only 200AH but just upgraded to 400AH. With 200AH things worked a lot better then AGM. However you can't charge them like AGM and you need a BMS. You can't float them and with AGM tied together, AGM will draw the LiFePO4 down. So unless the AGM's are charging or
LiFePO4 are low then they are disconnected from the starting batteries. Also when they get to full voltage they disconnect. This keeps them charged when plugged in, driving etc. It's automated so we don't have to think about it. It's nice that LiFePO4 keep their voltage so things work well and don't get the lead acid slow down. One down side to LiFePO4 is you can charge them below freezing. They are expensive but AGM are not cheap and they cycle out quickly. With LiFePO4 we don't have to worry about having the lights on etc. and will we get though the night with heat. Using higher voltage panels, the wiring can be smaller from the panels with less loss.
Long term we don't get enough solar to keep going but since we mostly dry camp and for a weekend it is good enough. Summer is better then spring/fall. Having 1200W of solar would probably work okay for us. I've been thinking of adding a couple of flip up "awning" panels over the day and kitchen window but haven't found a good powered mount system yet. Driving across country dry camping at night is fine since the alternator helps keeps the batteries up. Worst case extended dry camping we can fire up the generator for an hour and get everything up to charge with the upgraded CC/CV charging. Chances are we'll have the AC on sometimes so the generator will have to run for that. It's nice not having to run the generator much when drying camping in generator city :-( With 400AH of LiFePO4 things should be better and we might leave the inverter on overnight.
Except for batteries and wire we got most of our stuff from
Solar Panels from Wholesale Solar
