It could be a short drawing the battery down. If that's the case, a bit of wire tracing will need to be done.
To check and see if the battery is getting enough charge, put a volt meter on the battery with the motorcycle running at a high idle, 2000-3000 RPMs. You should be reading somewhere over 14 volts. If not, the fault probably lies in the charging system.
To check and see if the battery is getting enough charge, put a volt meter on the battery with the motorcycle running at a high idle, 2000-3000 RPMs. You should be reading somewhere over 14 volts. If not, the fault probably lies in the charging system.