Are you using 1 or 2 starting batteries separate from your 6v Trojans? I know Russ on Time Out swears by 2 banks of 6 volt Trojans and he says he never has a problem. I just use 4-Delco or Interstate Deep Cycle Battarries and I get 3-4 years out of a set. Our Blackmans have an automatic switch solenoid which separaters the banks when the key is off.