flat battery

hi everyone. i am after some advice regarding my battery. i have a 1999 curvy and the battery was going flat. i put a volt meter on it and it read that while running the bike was putting 13.0 v through the battery. even so it kept going flat, so i presumed the battery was knackered and bought a new one. i charged it up for 6-7 hours last night and went out for an hour with normal head light on etc with occassional full beam. i went to work in the dark this morning, light on again on a 20 minute journey. i came out from work and the battery was flat again. surely the battery should last longer than this ?
what is my next move as this is starting to annoy me and could you tell me approx cost.

cheers if you can help. jim.

sounds like rectifier problem to me but i'm no expert but it is a common fault on curvy's mine went same sort of problems

there is one on evil bay starting at a tenner but you will probably pay 30-40
hope that helps

cheers dave, rectifier ! Right ! do you know if i can do this myself or will i ave to pay someone ? do you know where it is on the bike ? am i impressing you with my mechanical know how ? !!

[Biker Biggles]

If you do a search for Sid Squids posts on here there is a guide to testing the charging system using your multimeter.Its not difficult but involves a bit more than just what you did.Id do that before buying anything as you may have a different problem.First thing Id check is all your battery connections and earths,as you may have a current drain somewhere.

[embee]

Like the others say, read up on the checks to make, but it sure sounds like regulator/rectifier is a prime suspect. 13V is too low for good charging, though it could be poor contacts somewhere.

Anyway, if it comes to it and you need to replace it, it lives behind the right side tail panel above the exhaust can. Removing the plastics is relatively straightforward, and providing you get the correct reg/rec then it's simply plug and play.

Electrex have a pretty good reputation for such items.

While you're about it check all the connectors and the fuses for clean contacts, they can get very cruddy which will cause voltage drops when under load. Don't forget the main 35A fuse in the main relay (green cover IIRC).