Hi can anyone help with an electrical fault on my fazzer.

Batt keep going flat.

Got a new batt for it, but still having same prob, checked in mantinace manuel,

and tested alternater, the readings are a bit higher than in the book but not alot, dose anyone know how to test the rectifier.

Can anyone please help?

What is the voltage across the battery terminals when the engine is running above idle?

hi the voltage is around 13.5 volts, but when i put the lights on the voltage drops to around 12.5