I, too, use this system. Turn one on, then turn the other off. No problems
in 6 years so far! I use a panel mounted digital display voltmeter, and
switch when it reads 12.0 v or is decreasing faster than it had been
decreasing. The batteries have 5 A fuses on them. Almost always I get by on
one battery--running a lot of electrics.

--
Hartley Falbaum
ASW27B "KF" USA


"Brian" wrote in message
oups.com...
Also just two on/off switches working pretty well as also. Then you can
decide if you want to "Make before break" or not. Althought the two
batteries will probably be connected for a longer time. as you switch.