battery odyssey

[gavb0]

Gents have not used my bike 1150 gsa for three weeks come to it yesterday and it was flat no clock nothing(i had not left anything on) charged it over night everything ok got a volt meter on the jump start posts 12.8 not running 13.8 running but when i increase revs does not go up when i bought the bike had a reciept for the odyssey battery its about 8 months old is this normal thought these batterys held a charge for ages ,Can some one advice me if the alternator outputs are ok checked the threads but still a bit confused. Do i buy a new battery or recon alternator from motorworks?
Gav

 

[wessie]

It takes 3 months of non-use for the clock to drain my Odyssey battery to a point where it won't start the bike. That's only a drop down to 11V or so. I found this out when I injured my knee and couldn't ride for 5 months.

You could have another active circuit on the bike in addition to the LCD clock. Does it have an alarm? It could be a faulty circuit such as a stuck relay or leaking diode. Your battery voltages sound okay. Have you got a decent ammeter available ( a digital mulitmeter won't be rated high enough)? Connecting this into the battery circuit would soon tell you if there is a current drain when the bike is idle. It would be a fairly simple job to isolate the faulty circuit then by removing fuses & relays one at a time.

Of course, the fault might just go away. Especially if it was a stuck relay. I'd ride the bike a few miles and then check the battery voltages again. If the voltages read what you reported above then I'd put it down to a transient gremlin and stop worrying.

 

[gavb0]

Thanks Wessie think your right about somthing draining the battery i will ride it for a while to see what happens ,A mate told me it should output 14.5 when reved to 3500 is that right because mines not going up no where near that 13.9-14.0 at best

 

[wessie]

Thanks Wessie think your right about somthing draining the battery i will ride it for a while to see what happens ,A mate told me it should output 14.5 when reved to 3500 is that right because mines not going up no where near that 13.9-14.0 at best

Your mate is making an incorrect generalisation. The voltage measured at 3500 rpm will vary from vehicle to vehicle. There are many variables such as the load on the system, the voltage regulator, the type of battery in circuit and ambient temperature.

At this time of year in the UK 13.8V is fine.
The battery FAQ says to look for anything between 13-15V. If the fault comes back then there's lots of advice on fault finding in http://www.batteryfaq.org/

 

[gavb0]

thanks Wessie checked it this morning and it still holding a charge so thinking must have been a one off maybe sticking relay like you said
thanks again for a quick response Gav