The Problem With the Guest Charger ...........
.......... is that they are programmed (if you can program a shoe box) to cut back to a float charge at 2.0 amps input to the batteries. Now, normally this is not a problem if you only have one or two batteries in the system being charged. However, with three batteries (perhaps one starter and two house batteries) these will NOT drop down to 2.0 amps and will continue to pump in about 6 to 8 amps at 14.8 V. This will eventually gas off enough water to expose the plates and there go your batteries. The one exception to this behaviour is cold weather. I have noticed that in the cold weather, that true to any chemical reaction, the acceptance rate of the battery is lower and the batteries will drop down to an input of 2.0 amps causing the charger to cut back to float. So, until I can afford to install a proper charger, I have to keep checking up on the charger to see what it's doing (this is where a battery monitor is invaluable). If it's trying to overcharge, switching the charger OFF and then ON will trick it into cutting back to float. Otherwise, it's fine in the dead of winter. Incidentally, after e-mailing Guest and discussing the problem, they freely admitted that they new there was a problem with the charger but continued to sell them. The charger actually requires a temperature monitor. In their own words "if you know how to get around the problem, they're a great charger". About par for the course for most pleasure boating gear. Regards, s/v Island Hunter
