Is my battery knackered?

[Morespeedvicar]

A battery should keep for years if it not got any fluid in it, aslong as you keep it dry. Dont charge it much over 15 volts, it'll fine aslong as it doesnt get warm, for a fast charge. A flat battery can pulg 8odd amps at 14v charge rate whcih is what the bike charges at anyway. But if you do get a new one trickle charge it before you use it.
I'd still start with the reg mate to be honest. It could be the stator but with taking the engine genny cover off your never going to know unless its shorting to ground?
Cheers
Ian

[speedy231278]

I've not checked the stator for shorts to ground, just the resistance between the windings. I'll check that when I'm next back home. Whever I've checked it in the past, the resistances and output have been spot on when relatively cold, but I've never measured those when I've been out and everything is toasty warm.

Having thought a bit more about it, I'm leaning more towards it being the reg or stator than the battery, and that the battery seems a little less sprightly these days because it's been killed or nearly killed several times in fairly quick succession.

Having thought even more and checked the dates, I think this issue started cropping up when I had cause to start the 'odd starting issue' thread after I went to Eastbourne, got lost in squillion degree heat for a couple of hours, and the bike stalled and wouldn't start again when I got to Beachy Head. No, not to throw myself off, but to see a certain triangular object in action (http://s1082.beta.photobucket.com/user/ ... rne%202012). Being hopeless, I didn't venture anywhere near the clifftop, and missed out on some amazing slights! Anyway, this was before my issue with the wire breaking on the alternator connector, which happened the night before the show at Dunsfold (another shameless plug http://s1082.beta.photobucket.com/user/ ... els%202012) so I'm happy it's not a fault in the loom as I've made good all the repairs that have ever been done on the charging circuit, and all the connections are now crimped, soldered, and have brand new connectors on them for good measure. At this rate, I might sort out the awful job I made of the headlight ones too!

So, I'm going to order a new reg. Yes, I have a spare, but as I said before, it has no fins, and is either an OE one, or a copy of the OE one, so it'll probably fry very quickly if it turns out that that is what I need. I wonder if Eastbourne might have killed it due to the heat. It would be somewhat ironic, as my pic of the bike in the new members introduction where it's posed with the Vulcan in her hangar at RAF Lyneham was the day before the old reg/rec died on the way back home, and I came to a stop in the one-way system in Guildford in the rush hour....

That just brings up the question of which Optimate or equivalent, and which battery, but that's not really relevant for this thread.

[speedy231278]

New reg, . battery and Optimate ordered today. Possibly a tad extravagant to do all at once, but every time I go back home to fix the issue, it's £20 in train fare and both directions add up to about seven hours travel! So, unless there's something utterly dramatically weird going on, my next visit home should cure it!

[speedy231278]

Right, the battery was charged over a week ago (10 days to be precise) on my behalf. It came off of charge pretty high, at mid 13s. After a day or so it had settled down to a little over 12.9V and last night when I got home it was 12.84V, so it certainly seems to be able to hold it's own. So this morning I plumbed everything back together, complete with a volt meter intended to be plugging into a car cigarette lighter socket. After a little modification, I now have a voltage readout on the fuel tanmk whcih I can turn on and off as and when I choose. Unfortunately, it's about as accurate as a scud missile, and reads about half a volt low. Not the end of the world as all it is needed for is to tell me if the voltage is changing as would be expected, or has dropped back to the level the battery is currently charged to and the circuit isn't doing anything.

The plan was to ride about until the circuit died, then measure the alternator output to see if that had packed up, and then blame the reg/rec or not. In the end, it stopped working just before I swung my leg over the bike, so I quickly unplugged the alternator and measured it. 13V across each pair, so that was good enough to convince me to change the reg/rec. Rather disappointed that this one doesn't manage quite 14V at 5K, and is a pretty dismal 12.6/7V at best at idle. Also, it was rather annoying that after I plugged everything back together, I statrted the bike to see if the reg/rec would start working again, and of course it did. However, with the new one attached off I went, and covered the best part of 50 miles all told.

The readout changed as would be expected, a volt or so lower at idle than at slightly faster to medium speeds. I did notice that over 5K it did seem to drop a tiny bit, but only by a tenth or two. However, I did notice something that bothers me. Maybe it shouldn't, but I reckon there's possibly still something not quite right somewhere. After plenty of miles, I finally came across somewhere where I could give the bike plenty of beans for literally a few hundred yards, and I discovered that the voltage readout plummeted after having used more than 10K, and when the revs dropped back down, the voltage didn't pick up. It hung at about what would equal a normally charged battery give or take the error on the crappy meter I'm using. It did fluctuate up and down a few tenths suggesting that some charge was happening, but at 5K it was seemingly doing the square root of bugger all. I decided to head for home, but lo and behold, after stopping briefly at a roundabout, it suddenly perked up again. A bit later, I tried the same thing, and the same result ensued. As soon as I noticed it had picked up again, I gave it a little more, and this time the voltage was killed off at 6-7K rather than 10. Yet, once more, everything returned to normal after a few minutes pottering around.

I got home after havign managed to get the system to seemingly sulk again so I could measure it with a multimeter, but it picked up a few tenths between me parking the bike and fetching the meter, and with the proper meter the idle measured what it did before I set off. Switching off, the battery was 12.84V. I decided to leave the bike ticking over for a while to build up some more heat to see if the issue us heat related (ie give a handful out on the road, maybe something gets warmed up a bit), but the system kept charging away fine. I glanced at the temp gauge and nearly died as it had suddenly rocketed over to almost touching the red, so I took the bike out for a quiet tootle for a few miles just to blow some cold air through it. Came back, measured again, 12.98V on the battery.

So, if I didn't have this meter, I'd now be saying job done after changing the reg/rec. I've done nearly twice the miles that discharged the battery to 9.5 while running, the other unit stpped doing anything after a couple of mins idle until the bike was stopped and restarted a few mins later, and the new unit never completely stopped working at any point. However, I'm disturbed by the lack of volts immediately after using plenty of revs for a brief time, by which I mean a handful of seconds rather than several miles. I can't think how that can be right unless it simply means that at high rpms the ignition is munching up just about as much charge as can be made? Clearly, I can't stare at the readout to see if it comes back to normal like throwing a switch, or if it gradually builds up like the battery is recharging. I'm off now to find a nice bit of dual carriageway to see what happens when I am able to spend a good few miles at a reasonable, although the idea of not using top gear in order to keep the revs high enough to prove or disprove the issue seems a bit alien to me... :s

Am I just looking for a problem that doesn't exist?

[speedy231278]

Right, loads of dual carriageway miles done. Spent ages with the meter showing about 12.4V which by it's half volt missing crapness it means 12.8/9. Dragged down to 12.0/1 at low revs. On two occasions, it sprang back up to reading mid 13s as soon as the bike came to a stop. I'm now going to stick the old reg/rec back on to see what happens. If I've gauged the inaccuracy of the meter right, I'll find 13V on the battery when I get back, so whatever is going on, I either didn't stop on the occasion when the battery went way under the limit when I found the issue, or maybe the battery and the reg have gone all weird in sympathy with one another?

[speedy231278]

Now I'm really bloody confused. I put the old reg/rec on and spent 25 miles trying to get it to stop working. This morning, it stopped working after the bike had been idling for just a few minutes. It behaved impeccably, and if my slightly iffy voltmeter is to be believed, it's a good half volt better than the new one. No drops in volts after giving lots of beans, worked like a dream the whole time. So, I figured maybe the issue was a dodgy wire and in changing things about I'd 'fixed' it. Put the new reg/rec back on again, and after plenty of trying I eventually managed to make it drop volts again.

Regardless of the figures I've been seeing, the fact remains that today I've done 125 miles, and each time I've measured the battery with a decent meter, it's been spot on the money. That still doesn't explain it running down a few times recently, nor the fact that after I first direct wired the reg/rec to the battery the charging circuit still appeared to be iffy.

I suppose the next step would be to direct wire the alternator, to eliminate the rest of the stock wiring as maybe being the issue, although I find it odd that both times I tested the new reg/rec it played about, and the old one didn't. I guess I should have run down the road before swapping it the first time to see what happened, but I was convinced it had packed up.

[Neosophist]

so I quickly unplugged the alternator and measured it. 13V across each pair, so that was good enough to convince me to change the reg/rec. Rather disappointed that this one doesn't manage quite 14V at 5K, and is a pretty dismal 12.6/7V at best at idle. Also, it was rather annoying that after I plugged everything back together, I statrted the bike to see if the reg/rec would start working again, and of course it did. However, with the new one attached off I went, and covered the best part of 50 miles all told.

You unligged the altenator and measure 13 volt where?

im really confused as to why you would do that.

[Neosophist]

so I quickly unplugged the alternator and measured it. 13V across each pair, so that was good enough to convince me to change the reg/rec. Rather disappointed that this one doesn't manage quite 14V at 5K, and is a pretty dismal 12.6/7V at best at idle. Also, it was rather annoying that after I plugged everything back together, I statrted the bike to see if the reg/rec would start working again, and of course it did. However, with the new one attached off I went, and covered the best part of 50 miles all told.

You unligged the altenator and measure 13 volt where?

im really confused as to why you would do that.

[speedy231278]

Alternator was putting out 13V across any given pair of wires at the connector with no load on it at idle. I did it to prove that is was putting out anything at all. According to the figures either you or one of the other people here who are familiar with charging systems, it should be around 13V at idle and 50-60V at 5K with no load, ie unplugged.

Edit: just checked back. Both you (Neo) and magg have given previous advice to check open circuit voltage on the alternator, and that around 13V idle and around 50V at 5K should be present. At idle, after a few minutes at over 13V, the circuit measurement had fallen back to battery voltage level (ie the same reading as when the ignition was off, so I immediately unplugged the alternator to measure it to see if there was any output, and it was normal.

[speedy231278]

OK, as I've probably confused everyone with an excess of detail, here's my current state of confusion in a relative nutshell:

Battery charged and found to still hold decent charge level more than a week later (12.84V after 10 days).

Reg/rec connector replaced, all connections made using crimps on good quality wire and soldered. Output direct to battery. Alternator checks out fine, and charging output much healthier than before, but appears to stop working after a few mins. Voltmeter connected to battery and display attached to tank to allow on the move reading to be taken (where safe to do so, of course!).

Reading shows old reg/rec stops working almost immediately after bike started. No on road test taken, perhaps a mistake in hindsight.

New reg/rec fitted. On the move readings indicate adequate charging voltage for many miles until 10K rpm or higher used, whereupon it drops to near zero output (ie meter reads approx battery charge level only) until the bike is run at sub 6K for several miles, then instantly jumps back up to previous figure.

Old reg/rec refitted. Shows better charging voltage all round, and all attempts to replicate the fault above fail.

New reg/rec refitted. High rev voltage loss issue reappears.

I'd previously tested the alternator output when the charging circuit appeared to fail, and it was fine. I'm confused as to why the new reg/rec behaves the way it does, unless maybe one of the alternator wires is dodgy and I coincidentally managed to 'fix' it when I reattached the old reg/rec. Or, is it one of those reg/recs that switches the output off when the battery voltage is adequate? I doubt it for £35..... Maybe the new one is duff, but that doesn't explain why the old one that didn't seem to want to work it now working.

I'm going to direct wire the alternator next time I'm back, to eliminate the possibility of an iffy wire in the loom between the alternator and reg/rec. Then I'll know it's not an intermittent wiring issue and there's a crap component.