2009 XB12R

Battery was bought in Septemeber 2020, bike has regular use and I'm in Hong Kong so never gets cold.

I keep getting the "Low battery error" so I did the voltmeter mod. Checked the voltmeter against my multimeter for accuracy and it's all good.

When riding the bike is between 12 - 13.6V, kinda expected higher when on the highway.

Last week the voltage dropped down to 10v steadily as I was on the highway when I was going slower the voltage was back up to 13. That afternoon I had to jump-start the bike as the battery didn't have enough juice. Yesterday the voltage was fine on the way to work but the bike needed jump-starting again. Started fine this morning. Seems the problem only occurs on the highway with the voltage dropping.


A month ago I was using the ECM droid and forgot to turn the ignition off for a few hours and fully drained the battery, have I screwed it you think?

Other stuff I've checked:
Cleaned the earths
Tested the stator (60v at 3000rpm)
Tested the rectifier, it seemed like one of the resistance figures was incorrect. I can't remember exactly but from one pin to ground it was 1ohm and the other was meant to be 3 bit was something like 6.

Do you think its the rectifier or something else?

Sorry for the lengthy post. Any input greatly appreciated.

Thanks