Alleycat Too

Thanks, I think you are right. One thing we are considering is if we could re-set the state of charge- DC voltage on the memory display back to zero maybe it would charge. We don't see anyway to change that. After disconnecting power it should go to zero but reads 16 volts when re-connecting. Thanks everyone for your ideas.

Yes we isolated the batteries from the entire boat equipment and then connected to charger. Voltage on charger showed 16 volts and then connected to AC power. The display showed 16.22 volts - no change. Charger started charge cycle for about 1 minute than shut down. Boat is in Guatemala. Voltage output was the default value.

Yes we did isolate the charger for a test. The same thing happened - the charger started to charge, fan came on, amps started to increase and then the unit stopped charging. Voltage read 16.22 at beginning and end of trial. Yes this is a new installation on this boat, but it was taken off another boat where they said it worked fine. It is at least 3-4 years old. The unit has a display that shows a variety of parameters when connected. This unit says only ChargeMaster. No plus indicated anywhere. Probably predates the plus model? Any equivalent control alt delete reset possible to re-boot? Thanks folks.

Yes we checked all of that multiple times. We think it must be a problem with unit incorrectly reading battery voltage - not connections.

We are having a problem with a Mastervolt 12/100-3 Chargemaster charger. Following installation the LED reads 16.22 volts on batteries and then shuts down and will not charge. Voltage on batteries is actually at 12.8 volts. At the very least we should go to float even with charge at 100% full. Any ideas?