Volt meter on battery while running output?

[Quinc]

760 electrical with Zeel. Noticed battery is not charging. Swapped out the lighting coil on the stator and put the volt meter on the battery and started it and it went from 12.76 to 5 to 8 to 12.76 to 6 to 12.77 to 7 etc. Is that normal? I was expecting it to be around 13 and fairly steady.

 

[Harbor]

I’ve never seen those lower voltages. I did see about 12.77 or .2v higher than engine off battery voltage with 62t electrics, just quick testing on stand in the garage fir a few seconds of run time..

It threw me, I was expecting 13v like you mentioned but only got .2v more than battery volts… it didn’t have a charging issue too…

think if I put the boat in the water and could run it longer I’d see more voltage over a period of run time as it needed it.. the garage quick test seems invalid as I can’t hold a high rev long enough lol

 

[Carrera911]

Had the same issue trying to diagnose a bad rectifier. Starting it without the hose for 20 seconds wouldn’t even get the battery to where it was before using the starter and dropping the voltage.
On the hose for about 1 minute holding the throttle at 1/4 to 1/2 blips I was finally able to get it up like .2 volts above resting voltage. The output on these things must be pathetically small and only does much at all above 1/2 throttle. I seem to remember reading a spec of 2 amps output but I’d think that would raise the voltage faster on a small battery like this.


Sent from my iPhone using Tapatalk

 

[kevbo]

The old single coil charging systems are just barely enough to keep a battery up for average use. Kawasaki 750-800s were noticeably better but they did get hot. I remember the front cover being the hottest part of the entire engine.