admin wrote:I took his comment to refer to just having a switch to select battery 1 or 2 but I see you read it properly!
All our suggestions are more like thinking out loud anyway as the price of a converter suggests it's the easy way out.
Hi Admin
You posted while i was typing the below
IF the OP is happy to closely monitor his discharge & charge voltages &
with the light loads [probably less than 10A] he has indicated,
he can use ,A single pole, double throw , centre" off" switch [current rating to suit the max 12V load] Jay car part#ST-0576
Bridge ternminals to make a single pole 20A , Load to centre terminals, batteries POS to each end !!
That is as simple & as cheap as it can be
BUT WATCH those discharge voltages with good meters, one on each battery,reading to TWO decimal places
With his system ,much better to watch the discharge voltages, & keep them even rather than try to balance the charging.
ps I think that as time goes on that 12V load may increase
PeterQ