Voltage issue

[Little Tunny]

I have a lowrance information platform on my Sea Hunt boat and a 1985 Merc xr2 150 black max.
When cruisng, I read on my staus page that votage is 11.0 to 10.8 volts. I have a 2 battery system with a Perko selector and keep it set to ALL.
This seems low to me but dont really know. Should I have my alternator checked?

 

[Alumarine]

Re: Voltage issue

With the engine running at 1000-1500 rpm check the voltage at the battery(s) with a multi meter.

 

[Chris1956]

Re: Voltage issue

Clearly that is a low voltage. It sounds like the rectifier or voltage regulator is faulty