Batteries, solar and dry camping!

[pgandw]

Originally Posted by MarkMtl

Thank you.


How long would it take to charge one 12 v or two 6v with a 2000 watt (1600 watt nominal output) inverter generator?


what will allow me the most dry time....two 6v or two 12v batteries?

The typical Group 24 12V battery is 80-85 AH, for a total of 160AH. The typical GC-2 6V battery (Costco or Sam's Club) is the same size, except for an inch taller. But the GC-2s will have 205-252 AH.

Charging flooded batteries is very non-linear. Assuming you have a properly-sized Progressive Dynamics converter (or some other brand) that will hold bulk charge to 90%, it takes about 3 hours to charge your batteries from 50%-90%, with the highest rate of charge coming in the 1st 10 minutes and tapering from there. It will take at least another 3 hours to take your batteries from 90% to 100%. Trying to charge batteries faster (using higher voltages) results in gassing, boiling, and possible over-heating.

Because of the charge curves, most dry campers with generators run their generators 2-3 hours a day, which leaves their batteries at about 90% (depends on how low they were when you started the generator). The battery bank is sized so that you use less than 40% of the battery's charge between generator runs. That means, with 12V batteries, you use less than 64AH between generator runs. If you are careful with electrical consumption, you can spread those 64AH over 2 days.

Using 6V GC-2s gives you a little more usable power between generator runs (92AH for my 232AH GC-2s). I can cut my power usage to about 20-25AH/day with 4 hours heater run time at night in my little A-frame, so my GC-2s can go as long as 4 nights without recharging.

PS: The stock WFCO converters will NOT charge your batteries this quickly. A WFCO converter, even when working correctly, exits bulk mode rather soon, and so your charging tapers off, and takes a lot longer at 13.7V. If you are going to invest in a generator for battery charging, replace the WFCO.

Hope this helps
Fred W
2014 Rockwood A122 A-frame
2008 Hyundai Entourage minivan
camping Colorado and adjacent states one weekend at a time