Voltage at Battery Terminal when boat motor is running?

[Woodbinekeith]

Have a 1984 Evinrude 115 VRO. To check on whether or not the motor is charging the battery while running on hose/muffs, what would be a good voltage reading across the battery terminals. It the boat motor is not charging, what range would the reading likely be?

At full charge and not connected to anything, the battery reads 12.5 volts and readily starts the motor.

 

[jakedaawg]

Above 13 less than 14.5

 

[Gary H NC]

On those older engines it depends on what regulator-rectifier it has...I'm not sure what one the 84 model uses.
I would look it up in the engine parts section..

On my 81 model it is low amperage but increases with engine speed.
With my digital voltage gauge I have seen mine charge up to 15 volts at higher rpms.
Depends on how much drain was put on the battery..

 

[F_R]

What Gary said--it depends. In any case, if all accessories are turned off, it should show higher voltage after running awhile (you have to give it some time) than it did before starting. That proves the charging system is working. Regulated systems will go up to around 14.5 with a good run, unregulated ones can go up to 16, sometimes even more.

 

[rob 135]

At idle only charges very little . I found hard way if you just start boat and go for very slow cruises, battery never recovers from starting or running acc. . So now before I dock I make sure to give some higher rpm runs to get voltage up enough to charge battery.

 

[Bosunsmate]

ive had mine get up to 17.8V at high rpm, Its unregulated and quite bad for the battery at that voltage so im adding a few electronic things to put a load on at that stage,

 

[Bobfox]

I am getting 14.9 at idle now. and 15 v at full throttle on a 2003 Yamaha 150 two stroke. is that OK?

 

[jbcurt00]

I am getting 14.9 at idle now. and 15 v at full throttle on a 2003 Yamaha 150 two stroke. is that OK?

Start a topic about your Yamaha 150, asking in a Evinrude 115 topic is considered a hijack