I'm resurrecting my old post with some questions re: battery charging. As I recall, last summer the solar kept the batteries about 12.6v after a day of charging, and down to about 12.1v in the morning, before the sun hit the solar panels. Everything worked (except for some fridge problems) and I don't think I ever had to use the generator last summer. I was able to run fridge, use lights, radio and run heater and water pump without ever running out of electricity. When the batteries got down to 12.1 or 12.2 in the evening, I'd run some jumper cables from the two 6v batteries to a backup 12v RV battery for peace of mind.
I hooked up the RV to shore power in an RV park for the winter, but now I'm back to boondocking for the summer. During the winter, I removed the two 6v batteries, took them home, fully charged them, then put on a trickle charger. The trickle charger was a small one for motorcycles, and never turned "green" (meaning fully charged).
Now I've put the batteries back in the RV and have the 45w solar panels hooked up. I run the fridge all week, but otherwise turn everything else on the trailer off from mon to friday. Saturday I show up and stay in the rv for the weekend.
Now for my question - after a full week of solar charge, the batteries were at about 12.6v when I arrived Fri night. By sat morning (after running heater for an hour), the batteries were at 12.1v, which quickly went up to about 12.5 v once the sun came up and hit the solar panels. I don't think the batteries ever get to 13v, let alone the 14.5v that Don had mentioned in an earlier response (not this summer or last summer). The volt readings are all off the charge controller that came with the harbor freight solar panels. I haven't checked with a multimeter to verify the charge controller reading.
I purchased the batteries early last summer from a shady battery shop near a bunch of auto dismantlers. Of course, I was told they were brand new, overstocks, but I think I only paid about $125.00 for both trojan 6v batteries, so who knows the true story. Then I let them get pretty discharged the first couple of weeks before I got the solar panels. Maybe my batteries aren't holding a charge?
I guess I'll try turning off the fridge and disconnecting everything from the batteries except the solar chargers this Sunday, and see if maybe there is a significant parasitic load. I'll see if next week the batteries at above 13v.
Should my batteries get up to 14.5v during the week? How low is "low" for discharge? I don't think I've seen below 12.1v since I've been boondocking this summer. The solar charge controller is wired directly to the + on one 6v batt and - on the other (with the other + and - connected to make it 12v).
Sorry for the long rant. I really appreciate all the help I've gotten so far.