470 Charging Volts

[pop pop]

I have a 1986 mercruiser 170 with the orginal charging system in it the question is what voltage should it be charging at. My system is putting out between 14 and 16 volts. Is this ok.Thanks for any replies in advance!

 

[Searay87]

Re: 470 Charging Volts

My 87 merc 3.0L 130 hp alternator output voltage on the panel voltmeter is 14 volts. Haven't check it with an accurate multi-meter but have no issues charging the battery.

 

[Silvertip]

Re: 470 Charging Volts

14 - 15 volts is fine. Anything over that and the battery may begin to lose water due to gassing. However, if you are looking at the voltmeter at the helm the error factor in the gauge may be the cause of the 16 volt reading. Use a quality hand-held meter to get a more accurate reading. If you run long distances at 16 volts, turn on some accessories to pull down the voltage a bit. Short runs at 16 volts won't bother anything but some electronics may shut down due to the built-in internal over voltage protection.

 

[pop pop]

Re: 470 Charging Volts

Thanks for the replies. Could that be a cause for a blown fuse to my depth - fish finder

 

[Silvertip]

Re: 470 Charging Volts

Possible but not likely. Locators generally have internal "overvoltage" protection and will simply shut down if there is either an over or under voltage situation.