Possible problem with alternator

[gibbo]

Your opinions on this are most welcome.

Had a nice 100 mile bimble on the K on Saturday, but arrived home and tried restarting the bike but the battery was flat as a proverbial pancake. The bike is always on a trickle charger when not in use and the battery is only nine months old.

So, charged the battery overnight and the bike started immediately and ran without fault. I connected a multimeter  to the battery and these were my findings :-

1. Battery without engine running 13.2 Volts (should be as I charged it overnight)

2. Engine running at 2K RPM, the multimeter reads 13.7 Volts.

3. Engine running at 2K RPM, with full beam, heated grips on low and cooling fan activated, the multimeter drops to 12.4
    Volts.

I'm no technophobe with performance figures for this, but It would seem that the alternator could be on the way out. It was only serviced by North Oxford a couple of weeks back and I did notice a slight smell of burning when I arrived home, but thought nothing of it, old oil etc on hot surfaces.

Anyway, I've sent off an e mail to NOG and have asked their opinion on the matter. Luckily, I have the extended warranty to cover the cost if necessary.

Again, your opinions on those multimeter figures are indeed welcome. 

[TomL]

I would have expected the voltage to remain at the higher reading, of 13.7volts, whatever is switched on.

I use a fluke oscilloscope to check alternator output and also check that it is charging on all phases. A multimeter cannot indicate if all phases are charging but it is not a good sign if the voltage drops off when more load is applied to the system.

[Costas]

Is this the original battery? The symptoms point towards a battery not the alternator, and would be very much surprised if the alternator in a canbus bike creates any issues.

[gibbo]

Thanks for your input Costas and Tom. The bike is a 2009 model and this battery has been installed for nine months. Current mileage recorded is 22K since new. The last battery had only been installed for just over a year and failed.

 I had an email back from my local BMW dealer who said that the current multimeter readings suggest that all is well, but they want the bike in for further checks. I've booked it in for next Thursday. Do all K bikes eat batteries like this?

[bobtail]

Thanks for your input Costas and Tom. The bike is a 2009 model and this battery has been installed for nine months. Current mileage recorded is 22K since new. The last battery had only been installed for just over a year and failed.

 I had an email back from my local BMW dealer who said that the current multimeter readings suggest that all is well, but they want the bike in for further checks. I've booked it in for next Thursday. Do all K bikes eat batteries like this?

Nope, well mine didn't! Over ten years on the original (still going strong when I sold the K12) and never a problem, just saying

Bob

[Phmode]

What battery are you using Jon? Is it the same make as the last one that failed?

My bike records suggest my bike has had four batteries in 11 years but the current one has been on since before I bought it four years ago with no problems. Always on an Optimate when not being used.

Brian (who thinks it needs to be stress tested with a big load and hopes it ain't the alternator)

[Costas]

There might be some kind of current constant consumption in this bike when its parked. Check nuvi and any other aux accessory that might uses current even when off. That is probably what dealer wants to see, the current consumption.

[TomL]

1. Battery without engine running 13.2 Volts (should be as I charged it overnight)

2. Engine running at 2K RPM, the multimeter reads 13.7 Volts.

3. Engine running at 2K RPM, with full beam, heated grips on low and cooling fan activated, the multimeter drops to 12.4
    Volts.

The meter should read the same in 2 and 3. If it doesn't then the alternator is faulty.

[Costas]

Disagree but if you are right it's the first k bike with alternator issue Ive herd of word wide.
Dealers have been issued a new portable instand multimeter that gives them all readings for electric circuit, they do not have it there? It's just a plug and play instrument , here all bikes that ender workshop are to be checked prior to return to costumer with it.

[TomL]

If it is only giving 12.4volts with all the bike electrics on then it will really struggle if the rider and pillion plug in their heated clothing. Alternator if you ask me.

[gibbo]

Thanks again everyone for your comments. 

Brian. I'm not too sure on the make of battery. On the invoice I received it states, BATTERY CTX14BS and I don't know the previous make of battery either (very helpful aren't I). There would seem to be no official data on alternator outputs, only that it's 3 phase 580 watts. 12.4 volts with everything on seems a bit low to me, but I'm no expert on these matters.

Costas. I don't have any additional accessory on the bike, only factory fitted stuff.

I'll wait to see what happens on Thurs at NOG.

[midlife crisis]

Hi

I did not have any problems with the battery on my first k1300GT but my second has recently had a problem on my tour of Scotland

I had to go to Mitchell's in Inverness to get new tyres, another story, and when I got there I parked up the bike, they then asked me to move the bike and it wouldn't start. I then went into grumpy mode as thought it must be switch which stopped my french Alps trip.

however they told me to leave the bike and they would look at it, when i returned the next day they had fitted a new battery and it was working again. I then got emotional and wanted to hug all the mechanics but they were not impressed.

The bike had only done 15,000 miles since 2011. I have it irregularly on an optimate.

Graham

[Phmode]

C'mon Graham, irregularly is why it starts irregularly 

Brian (whose bike starts smugly on the button, Optimate or not, right up to the point where it won't  )

[Costas]

I know no rider with a k 13 bike here that had a battery for more than two years, optimiate - OEM chargers or other. February installed a li-ion battery and now awaiting to comment on its performance.

[Philip]

Maybee i'm the only one then Costas.

I bought my 2010 K1300S just over 3 years ago & havn't had to renew the battery yet, touch head.

The service record that came with the bike showed no reference to a battery change, not to say the previous owner may have replaced it outside of the BMW dealer network.

I noticed during last winter that it was slower to turn over than usual, so bought a replacement dry charged battery with the acid separate in six plastic containers.
I havn't had to press it into service yet, but have that satisfying feeling if it should fail, of having an instant back-up available.

So I would guess my battery is probably original.

Since last winter I usually connect the battery conditioner the night before I will be using it & it turns the engine over with no problem.

Looking at Gibbo's problem, seems to me it must be an alternator fault or a loose conection somewhere in the charging circuit.
The alternator should be capable of supplying all the power needs plus extra to charge the battery.
The voltage should always be above 13v with the engine running.
12.4v means the battery is dis-charging.