Or, being me, perhaps that ought to be moron's charging issues.... The answer is probably still going to be crappy wiring, however, you never know...!

Some while ago I posted about an odd issue I had where I arrived at a destination after several hours travel, only for the bike to cut out, and the starter be unable to crank the engine over like the battery was flat, only for it to perk up 10/15 mins later like nothing was wrong. You may recall that I have had an issue recently where the alternator wiring connector was found to have corroded wires, and I cut and crimped them back up, but after being out on the bike I came back a week later to find a flat battery, after which I charged it, soldered the previously crimped wires, and everything was fine thereafter.

Well, it clearly wasn't, or I've upset something after I had the subframe off to clean it up. Last weekend, I did plenty of miles on the bike to make sure I hadn't broken anything in general, and the charging system most specifically. I went to several places, started the bike a number of times, and everything was normal. This weekend just gone, I went to take the bike out before I needed it the following day, and noticed the rear lights weren't working. I guessed there was an issue with the connector for them and I was right. However, I decided to measure the battery as the seat was off, and it had a truly inspiring 12.12V on it. Wondering if something was adrift after the recent work, I unwrapped the connections on the reg/rec and tested the resistance between the yellow wires mainly to check connectivity between the alternator and the reg/rec. All were in spec. I also checked to see if the DC voltage present at the reg/rec end of the loom matched the battery temrinals, which it did. The bike started without much fuss, and was producing decent numbers. I checked the integrity of all the connectors, before giving them a little nip up, and connecting the reg/rec back up again. The headlights showed a slight increase in glowing when the engine was revved, and the battery terminals measured mid 13s at around 5K with spikes to 14 or so when the throttle was shut. Tickover was about 12.8. I went out for a ride and everything seemed happy.

Yesterday, I arrived at my destination convinced all was not quite 100% right, I was sure that after hitting a big bump the bike felt a little different (but then I'm paranoid!), so I blipped the throttle a few times before I turned it off and neither the headlights nor the neutral light responded in the usual manner. I turned the bike off, and came back to it about 10 mins later. It started, but barely. A few hours later, I took the side panel off to check the alternator wiring connector, and while I was able to push one of the pins in a bit further, it was not out anything like far enough to be disconnected. However, the lights glowed a little brighter with the throttle so I went off for a short ride, and made it back, albeit with the lights again having stopped responding to the throttle. I checked the connector again at lunchtime, and nothing has shifted. Lights were responding again, so I went out again, and once more made it back, and once more no extra glowing with throttle. Having had the bike die within five miles when the system broke completely, I figured it was just being quite inefficient, and took my chances coming home in the evening. I made it home with no issues, and the bike felt fine. However, I was convinced it was not right as the dash seemed slightly dim, so before I shut it off, I got the seat off and measured the battery, and almost died. Very slightly over 9.5V at idle, and as I suspected from the neutral light not flickering a little, it didn't change at all when I increased the revs. Naturally, the solenoid wouldn't throw, so I'm bloody glad I didn't get petrol on the way back.

What I find really confusing is that when switching off, the battery voltage jumped up, as you would expect when the lights go off, to about 10.5V, but then slowly kept increasing. I didn't have time to stay and watch it, but within two mins it was up to 11.2! Also, how did I managed to get so far if the system was broken? If it did break when I hit that lump, I managed about 35 miles on it, which is a lot more than I would expect, notwithstanding the fact that last time the battery was older and I replaced it not long after. This one isn't exactly a spring chicken either.

Clearly, there's still an issue, and I'm still convinced it's a crap wire or connector somewhere hence the intermittent charging, but I'm still a bit confused seeing as that if I'd checked everything on the bike on Saturday bar the battery voltage, I'd have concluded that nothing had ever been wrong. I still find it weird that I had a flat battery a few weeks ago, and a few weeks before that, one that went flat enough not to be able to start the bike, but 10 mins later started it like nothing had ever been wrong. I have the necessary wire, fuseholder and connectors to rewire the whole system from alternator to battery which I hope will sort it out, and of course I'll double check the battery leads, etc, but everything seems in good shape. I'm wondering if I might possibly have more issues than just the crap wires, and maybe an iffy battery or a leak to ground somewhere?

Sound like a dud battery i.e. a weak cell. Have you tried a load test. Fully charged bateery should be able to run hi beam lights for 30 minutes without battery voltage dropping below 12 volts.

I shall do that next time I am back. The only thing that makes me suspect it might not just be the battery is that it's not being consistent. I went away for a week once and it seemed to go flat, yet the following time I left the bike it was for a fortnight, and it was fine! The battery was acquired early Jan 2009, which makes it the best part of four years old. To me, that's not ancient, but I'd expect another year or so before it starts getting ropey. Certainly before this started happening it still had plenty of get up and go when starting from cold.

I'll sort out the wiring next time I go back home, charge the battery, see how long full beam lasts (hopefully without destroying my light switch - I have proper Japanese spec headlamps but I'm still paranoid) and if it doesn't last very long I'll pronounce it dead.

I'm just confused as to how it kept running so long considering how quickly I got into trouble the last time the charging system was playing up! I'm still not entirely convinced I haven't upset something in the wiring, but I should find out soon enough.

Speedy

Even if you have a problem with the chgarging side of things (which it sounds like), when your system stops charging the bike will effectivly just start running a sort of total loss system - like some of the guys do with the race bikes.

As they can get a days racing, or at least a good few sessions, out of a full battery charge - and that is thrapping it, you should be able to get a good few miles berfore you compleatly run out of electrical power. Obviously running with the lights on if the charging system has packed up will shorten that battery life a bit though. If the charging fault is intermitant you may be running "total loss" sometimes and then if the system comes back on line it tries to catch up and revive the now depeated battery, hence why the charge seems to last different periods of time.

Electrical problems are a pain in the arse, and Intermitent ones are even worse Like all electrical problems, start at one end and work it through methodicaly and clean/check every conector and earth on the way.

Good luck and hope you solve it

Yup, pain in the bum. I'm currently working on 50/50 chance of intermittent charging circuit issue or tired battery. My gut feeling is the former seeing as I had all the back half of the bike off a few weeks ago, so I suspect I've upset a wire somewhere, and as I keep saying, everything on the charging circuit is a bit iffy and very shortly to be completely rewired in this area.

How old the battery? The longest ive got out of a battery is 6 years, but i never really use a trickle charger over winter. But id start with a new battery first at least you'll have a good starting point. If its charging over 13v then i wouldnt think its the charging circuit but if you connections are slack enough to half fall off over a bump then you could be chasing ya tail untill you get them all tight and cleaned up.
Cheers
Ian

You could check the condition of the connector at the starter relay and the main fuse. High resistance will give poor battery charging, varying system voltage and unreliable starter relay function.