13-11-14, 11:59 PM
As some of you may just remember I had some issues apparently with my battery some time ago (a lot of details follow, so some people may want to hit next message now... 
)
I put a new battery in and it seem to sort out the problem, but similar things seem to be happening again now, so I've looked into the matter further and I think there may be a fault with either the alternator or the rectifier.
Basically what happened is that, on Wednesday night I went to the dry ski-slope in Southampton and although it's a fast run along the motorway, when I get into town there's a lot of slow riding filtering through traffic before I get there.
The upshot of this was that when I was about to leave a couple of hours later, the bike was sluggish to turn over and it only just started at the point where I was thinking "Oh foc, I'm going to have to bump start it again".
When I got home I switched off (using the key) and then, out of interest, tried starting it again. It did start, although slightly reluctantly, but when I tried switching off and starting it once more, it turned over quite slowly and wouldn't fire and the battery was clearly getting drained.
So I charged the battery overnight on the Optimate, then this morning (just before midday) I checked the charge which was 13.18 volts. I started it, switched off and checked again, getting a reading of 12.5 volts
Following the advice in the Haynes Manual I then lifted the tank, disconnected the negative lead and checked the ammeter getting a reading of 1.5 milliamps with the alarm in service mode. This is slightly higher than standard, but it says that's to be expected with an alarm and it's not the sort of power drain that would suggest a short-circuit.
I left it for a few minutes and got a reading of 12.64 volts, so I started it again and got a reading of around 14 volts until it warmed up and then got 12.2 volts at idle.
Next I tried checking the voltage whilst revving and discovered that it would only get to about 13.8 volts at 5000 RPM and dropped to about 12.5 volts at idle.
This is more of a concern because, according to Haynes, the Regulated Voltage should be 14.1 to 14.9 volts at 5000 RPM.
I switched off, put the alarm in service mode again with a reading of 12.55 volts, started it once more, but after this it was sluggish to turn over and I couldn't get it to start any more.
I put it back on charge and about 3pm the Optimate said it was ok with a reading of 13.18 volts, but I noticed that the volts were starting to drop and a few minutes later it was 12.85 volts, but a check with the ammeter said it was still only drawing 1.5 milliamps.
I left it off the charger to see what would happen and at 16:45 it was 12.72v at 19:50 it was 12.65v and at 22:05 it was 12.63v, although when I tried to start it just before writing this, it seemed ok.
So it seems, from what Haynes says, that either the Alternator or possibly the Rectifier may be dodgy and the battery simply isn't getting the charge it needs.
Does this sound right and, if so, is there anything I can do about this or anything else I can check or do I just have to get a new Alternator or Rectfier?
Any useful suggestions would be appreciated.
)I put a new battery in and it seem to sort out the problem, but similar things seem to be happening again now, so I've looked into the matter further and I think there may be a fault with either the alternator or the rectifier.
Basically what happened is that, on Wednesday night I went to the dry ski-slope in Southampton and although it's a fast run along the motorway, when I get into town there's a lot of slow riding filtering through traffic before I get there.
The upshot of this was that when I was about to leave a couple of hours later, the bike was sluggish to turn over and it only just started at the point where I was thinking "Oh foc, I'm going to have to bump start it again".
When I got home I switched off (using the key) and then, out of interest, tried starting it again. It did start, although slightly reluctantly, but when I tried switching off and starting it once more, it turned over quite slowly and wouldn't fire and the battery was clearly getting drained.
So I charged the battery overnight on the Optimate, then this morning (just before midday) I checked the charge which was 13.18 volts. I started it, switched off and checked again, getting a reading of 12.5 volts
Following the advice in the Haynes Manual I then lifted the tank, disconnected the negative lead and checked the ammeter getting a reading of 1.5 milliamps with the alarm in service mode. This is slightly higher than standard, but it says that's to be expected with an alarm and it's not the sort of power drain that would suggest a short-circuit.
I left it for a few minutes and got a reading of 12.64 volts, so I started it again and got a reading of around 14 volts until it warmed up and then got 12.2 volts at idle.
Next I tried checking the voltage whilst revving and discovered that it would only get to about 13.8 volts at 5000 RPM and dropped to about 12.5 volts at idle.
This is more of a concern because, according to Haynes, the Regulated Voltage should be 14.1 to 14.9 volts at 5000 RPM.
I switched off, put the alarm in service mode again with a reading of 12.55 volts, started it once more, but after this it was sluggish to turn over and I couldn't get it to start any more.
I put it back on charge and about 3pm the Optimate said it was ok with a reading of 13.18 volts, but I noticed that the volts were starting to drop and a few minutes later it was 12.85 volts, but a check with the ammeter said it was still only drawing 1.5 milliamps.
I left it off the charger to see what would happen and at 16:45 it was 12.72v at 19:50 it was 12.65v and at 22:05 it was 12.63v, although when I tried to start it just before writing this, it seemed ok.
So it seems, from what Haynes says, that either the Alternator or possibly the Rectifier may be dodgy and the battery simply isn't getting the charge it needs.
Does this sound right and, if so, is there anything I can do about this or anything else I can check or do I just have to get a new Alternator or Rectfier?
Any useful suggestions would be appreciated.