Charging problem

[longumd]

Hi everyone,

I just got a 2003 GZ250 a month ago. It has a charging problem I guess. After I got it several days I could not start it, checked the battery voltage, about ~9.5V. So I charged it using a charger to ~12.5V and it was fine for 3-4times rides during two weeks then went back to 9.2V.

I charged it again and checked the current leak, there is no leak there. And I start the bike and checked the charging output (at 5000 rpm) , it was around 13.2V which is less than what the manual said (13.5V-15V).

I haven't done with all the electrical system check, I am wondering if someone had the same problem before and which part I should pay attention to when checking it.