You should charge at the C20 rate (or more) if possible.
ie a 100A/hr battery should be charged at a minimum of 5A, 2 @ 100A/hrs = 10A,........
You can not have too much solar, but you can have too little, unless you regularly charge with another source as well.
Cheers,
Peter
Aus-Kiwi said
01:30 PM Dec 8, 2013
I guess you work out load of fridge, freezer etc and % above that to charge batteries ? My new motor home has 120 watt which is only good for lights . The other bus motorhome ( which is far sale) has around 700w keeps both fridge, freezer going .. With some help from auxiliary alternator when driving or generator if required .
PeterD said
06:41 PM Dec 8, 2013
coyotte wrote:
"rule of thumb" or formula for working out Solar panel size relative to Battery size ????
The size of panel should be related to the load on the batteries rather than the size of the battery. You will have to tailor the panel size to both the daily current draw and the number of sun hours you expect to get each day. Collyn Rivers books explain how to figure this out and have maps to allow you to estimate the number of sun hours for all places in Oz. Jim gave you the link.
Coyotte
also Collyn River's very informative site ... http://www.caravanandmotorhomebooks.com/links.htm
The size of panel should be related to the load on the batteries rather than the size of the battery. You will have to tailor the panel size to both the daily current draw and the number of sun hours you expect to get each day. Collyn Rivers books explain how to figure this out and have maps to allow you to estimate the number of sun hours for all places in Oz. Jim gave you the link.