Sounds like it could be a alarm prob, as mine was (see post above).

It pays to check that the voltmeter still reads 14-ish volts with engine running when the engine is hot.

The voltmeters as recommended by Shazaam are a useful idea, but, be warned, they are not at all waterproof, and if left out the rain, or even during enthusiastic bike-washing, they will clap out. Best not to fix one permanently to the bike, I think.

Don't forget to examine the famous yellow wires, and their connections, between the alternator and reg/rect (behind the battery tray).

Moto748

Thanks, the alarm's disconnected right now, so I'll check the battery in a day or two. Also, the voltage when the r/r is good and hot, and the yellow wires. Maybe some soldering will be in order.

Good point about not connecting the little voltmeter permanently.

Andrew

You mentioned that you cleaned the battery _connections_ ... but the only prob I had with my old 916 was the earth connection - the metal right-angle bracket thing which only seems to add to the number of joints in the earth path. Undo all the connections in the earth path and make sure they are all clean on their mating surfaces and then snug them up and vaseline them (I can say that here can't i ?)
The battery earth path is often an overlooked cause of b'stard problems that are 2p to fix !