HP support page here your your model.
Not amazingly helpful though. Mainly saying try batttery only or charger only.
Where did you get your battery? Have you a link for it?
By the way, I see a Service and Maintenance Manual for the G61 is not listed for some reason. However it's the same as Compaq CQ61 (which is my laptop)
Sadly this time it doesn't help either. But may be of use in future.