Works awesome. I am just blown away how useful this is. It tracks my house bank amp-hours and my engine start and generator start battery voltages. I've set alert alarms for amp draw and voltage for my house bank as well as alarms for voltage on my gen and engine start batts. Just amazing how much this can do. I also wired up an external very loud audible alarm buzzer to alert me when my engine is running. The built in audible alarm may be loud enough for you if you have a well insulated engine room. In my case, the alarm is a bit faint when I have the main engine running, so I opted for the louder alarm - triggered by a built in relay. I had a Blue Sea 360 panel and it fit directly in place of my digital volt meter - that was not very useful.