Originally Posted by brian21BD
I appreciate all this information. I have charged my batteries and given them 24 hours rest to determine whether they are even holding a full charge. At this time (24 hrs later) they are both sitting at 13.00V. I guess I need to have a load test done to determine overall health. They haven't been used that many times, but I guess they could be toast. If I do need new batteries, then is a 200W solar panel enough to keep me up and running above the 50% with "normal" usage?
There are many web sites with instructions on how to calculate the size solar panel you need based on battery bank size and your predicted usage.
There are just too many variables to predict how much solar you would need.
I can tell you that 200 watts is enough to power a TV for a few hours and that is it.
A 100AH battery contains (12 volts X 100 amps) 1200 watts for 1 hour till dead (Math here is theoretical since it is impossible to get 100 amps out of a battery for an hour due to the Peukert Effect - PE) or 5 amps at 12 volts for 20 hours (5A x 20H = 100AH) which is the rating and also equal 1200 watt/hour @ 12 volts.
As discharge rate goes above 5 amps, the PE reduces the AH the battery can deliver.
For example, from the graph, we need 10 amps to run our camper. Due to PE, the capacity at that load drops to 78AH. So at 10 amps, the battery will last 78AH/10A or only 7.8 hours.
Remember that Peukert Effect impacts charging too. You just can not smash 1200 watt hours into a battery without burning it up.
If you charge at 10 amps, it will also TAKE 7.8 hours to replace that charge (provided your solar charge controller will do that, which it won't due to the charge rate dropping as the battery fills, just like your dedicated charger or Converter does).
If you plan on more than that you will need a lot of battery and a way to recharge them every day beyond solar (which will cut down on generator time each day).