Alarm Setting For Voltage?

[Madehn]

First a little history-while on passage and motoring my voltage regulator took a powder and started pumping 50+ volts through my boats system- fried the alternator, fried the batteries, fired the autopilot- in fact fried just about everything but the chicken.-- have replaced almoct all of the systems and have been looking at my new balmar smartguage-- it has a high voltage alarm function BUT i am not sure what value to set for it to "alarm" if I should have a similar failure, and the regulator starts sending juice at 20 volts will it sense 20 volts immediately at the batteries or is there some "buffer" caused by the large battery bank? I am thinking that i set the alarm to go off at 15.5 volts but would appreciate wiser heads than mine weighing in. Please explain your reasoning as well as the setting so that i can learn

[belizesailor]

I set mine a few tenths of a volt above normal max charge voltage. I want to know if voltage exceeds max normal charge voltage.

I had a controller start to fail a few years ago. It would intermitently ouput 16V. Alarm would sound. Reset it. Woud work fine for at least a few more days...sometimes as much as a week. Gimped by this way until I got a new controller in.