We have the Emon II H1 that was installed in 2005 on our 38’ sailboat. We purchased the unit directly from Ample Power in Seattle. The serial # is 10584 8.3. We’ve sailed almost 20,000 miles since the install and it's worked wonderfully.
We are in the South Pacific and the problem is that a couple of nights ago, it suddenly started showing a high rate of amp hours being consumed, fluctuating between 25 to 50 amps when we think there is no actual draw. There could be some small amp draw from an unknown source but it can't be what Emon is reporting. The battery voltage, as monitored by Emon, our inverter, and the multimeter, is 12.7-13.3 depending on the time of day. When we run the generator, the battery voltage comes up as it should but the amp hours being consumed are still off by 25-50. The solar relay is working and the battery voltage increases as it should during the day. If we really did have such a large draw on the batteries, they would be completely dead by now.
We have disconnected all three house batteries and the start battery and load tested each, watching the voltage. We applied a small load of about 7 amps for a few minutes and all appeared to operate normally. No one battery acted different than another (start battery is smaller so voltage dropped a little faster but that was to be expected). Our multimeter will only read a current of 400 mA and so I can’t check across the negative shut, where Emon’s sensing wires are connected, to see what that independent reading is but again, there is no way we are using 25-50 amps each hour based on the voltage of the batteries.
We have checked all connections, everything on the boat seems to be working fine, and we’re not sure what to try next. Is it possible that something has gone wrong in the unit itself? Any ideas?