Should I not use the echo charger on the genset battery? There should be no need to use an echo charger if the Northern Lights genset also charges its own start battery. Think about the battery in your car. The alternator output is sized and regulated to more than adequately replace the amount of current drawn out of the battery when starting. A properly balanced system will run without a fuss for years -- and most often die of old age. If you have to use an outside charger on it something is broke. Yes the echo charger will react badly to finding the genset's charge voltage on the battery. It seems as though you have correctly identified the reason the ProSine needed resetting. I had (and many others here did as well) lots of trouble with my ProSine 2000 and with attempts to get repairs on them. We went all through that a couple of years ago on this list, and we still revisit it from time to time. Your unit may or may not share the propensities for trouble that mine had. There appears to be some hope that Xantrex fixed the problem with the manufacturer. I would definitely take the echo charger off the genset start battery if the Northern Lights has a starter charging circuit, for fear of damaging either the ProSine, the echo charger or even the charging system on the Northern Lights. I also presume that the start battery for the genset is not used for much else, and that it is a proper starting design battery. Gary Bell