Battery charging question

[Roscoe P]

Another question from a newbie still learning. I have a Yamaha 40hp model C40TLRY with electric start. When the motor is running does it recharge the battery?

[boscoe99]

Assuming that everything works like it was designed, absolutely positively it recharges the battery.

Do you have a voltmeter? Before starting the motor measure the battery voltage. If fully charged it will be more or less 12.7 volts or so. Start the motor. Let it run for a minute or so. Check the voltage at the battery again. I suspect that you will see that it is more or less 13.5 thru 14. 5 volts.

Actually, the higher voltage is the output of a device on the motor known as a rectifier/regulator. The higher voltage on the motor will feed current to the battery and is doing, recharge the battery.

[99yam40]

Yes it should, but it only puts out about 6amps at high rpm so make sure to not hook up battery that in low and expect it to charge it is a little amount of running

[Roscoe P]

Thanks boscoe99. Leave the motor running or switch off before checking again?

[99yam40]

While it is running the voltage should be higher than just battery voltage

[Roscoe P]

I'll check it this evening. Thanks for the help!