Altinator putting out a way high voltage occasionally

[FKat 0]

I have an E36 318i and the altinator is putting out 17 volts plus at random times which is getting more and more frequently, I may be wrong but it seems like it tends to do it after I have been on gravel as well. Does anyone know if there is some sort of regulator you can get or would I just be needing a new altinator? I probably need to do something soon though before I fry my battery:S

[BM WORLD 1258]

i have replacements if needed .

021433600

papakura