battery charging issue.

[Big Mike]

2010 90 hp mercury 4 stroke motor is not keeping the battery charged.  I can run about a 1/2 day the and the volts continually drop down to around 11.5 and then will not turn over the motor.  I had the alternator and battery tested and they are both fine.  I have checked all connections and everything is clean and tight.  Anybody else ever have this issue. 

[fishinwrench]

Serial # ?

I will need to look up the charging system on that one.  Not yet familiar with it.   There may be a relay in the circuit.

Likely a stator and/or voltage regulator failure.

[Big Mike]

thanks Wrench, I will get the serial number tonight.  I think that the volt regulator is built into the alternator.