Telling if it's charging

[mylovelyhorse]

So I have a 2012 F800GS on which I have a small but reasonable amount of electrical gubbins, all currently wired direct to the battery:

- Garmin 590LM GPS
- heated jacket
- extra aux socket​

And of course I use the heated grips especially at this time of year.

The battery has been getting a little reluctant to start the bike recently - just now and then - never failing but sometimes the dash turns off during the start-up from cold.

Has anyone come up with a way of telling if the bike battery is getting sufficient charge while riding? I seem to vaguely recall an LED solution someone had found that could be wired in somehow and would glow different colours depending on charging condition. I shall do some googling but any recommendations or suggestions would be appreciated.

 

[(RIP) Tunneruk]

You'll need a multimeter -

Take a reading from the battery with the ignition off - Should be a little over 12v

Start the bike and hold the throttle at around 3k revs and measure again. You should see an increase to over 13v.

Then switch all your accessories on and do the same, the charging system should keep up with the demand.

If the voltage doesn't increase or struggles when you switch the extra kit on then there's a charging glitch, if it does increase / keep up then you either have a tired battery or a power leak. somewhere.

Be aware, if the battery is on it's way out then it will suddenly just fall off a cliff. You'll go to the bike one day, possibly having just ridden it somewhere and it'll be dead!

 

[mylovelyhorse]

You'll need a multimeter

Ah yes, thanks - I'm thinking more along the lines of on-the-move.

 

[(RIP) Tunneruk]

Ah yes, thanks - I'm thinking more along the lines of on-the-move.

I've edited my above post, have another read.

 

[earthmover]

I did have a LED indicator wired into Denise's 650 at one point. It did work, in that it showed us that the charging wasnt keeping up with demand, but it was because the stator was fried. Sounds very much like your symptoms I'm afraid. There is a thread on here about fried stators somewhere, we got it rewound locally for far less than BMW wanted for a new one, and it has been perfect since.
If you still want to try the LED indicator, it was off eBay for less than £20 I seem to recall.
Mark

 

[cookie]

sounds more like your battery's failing to me.

check the voltage rise as in post 2, if that's ok get the battery load tested.

 

[John Armstrong]

I've got one of these:

http://www.ebay.co.uk/itm/LED-Motor...ning-bike-G-/200826330214?hash=item2ec22e9c66

gives me an idea of battery status when moving and when parked up.

 

[vRSG60]

I had an issue when I fitted my Givi fog lights. 55W in each and with them on all day during a ride the bike was difficult to start the next day, battery almost flat. I've changed the bulbs to 35W each and now it's better, although if I have heated grips on too the sat nav doesn't charge!!!

 

[earthmover]

M

I've got one of these:

http://www.ebay.co.uk/itm/LED-Motor...ning-bike-G-/200826330214?hash=item2ec22e9c66

gives me an idea of battery status when moving and when parked up.

That's the very thing.
Mark

 

[mylovelyhorse]

I've got one of these:

http://www.ebay.co.uk/itm/LED-Motor...ning-bike-G-/200826330214?hash=item2ec22e9c66

gives me an idea of battery status when moving and when parked up.

I think that I might just have to get one of these - looks just the thing. I particularly like that it's waterproof. The only other thing I'd seen was rather vulnerable to water.

Thanks!

As it happens the bike has been starting much more enthusiastically since Tuesday's incident. Go figure.


Sent from my iPad using Tapatalk HD

 

[Nick V]

sounds more like your battery's failing to me.

check the voltage rise as in post 2, if that's ok get the battery load tested.

Seconded.
You mention that the bike is a 2012 model - that means your battery is now at least two years old.
Bike batteries get smaller and smaller with each generation, and the smaller they are, the less they can hold in reserve against cold weather. And lead-acid batteries really do not like cold weather.

 

[cristhemuso]

Hi my 2009 GS800 had the same symptoms. I thought it was the battery.....like people suggest. Turned out to be the alternator slowly failing. Charge voltage was a bit low so battery would discharge over a month and I would get the sluggush starting.
Easy check.... voltage at all revs above tickover 13.8 or 13.9 volts. Voltage at tickover 14.1 volts. Yes tickover is a bit higher and this is how the regulator works. I understand the charge voltage is set a bit low by BMW for the battery types fitted. Yours might peak at 14.4 being newer. Before I had alternator rewound the voltages were lower and the battery barely barely charged if at all. My theory is that the coils are wrapped in some kind of fabric and they overheat and charr. If you have the same problem you will see the coils all black. Many people have had this problem if you search.

 

[gsman1]

Does it work as I've just order done of these?

I've got one of these:
http://www.ebay.co.uk/itm/LED-Motor...ning-bike-G-/200826330214?hash=item2ec22e9c66

gives me an idea of battery status when moving and when parked up.

 

[mylovelyhorse]

OK so I've had the charge indicator from eBay fitted for some weeks now.

It was east to fit and locate; I have it by the ignition switch. While I was at it I revised the wiring for the GPS & Gerbing so that they only work when the ignition is on by means of a relay located under the seat. It happily glows green when the bike is running but switches to amber when ignition is off and CANBUS still active. I am taking this to mean that the battery is weak but not fatally so (yet). I get a healthy green flashing while the bike is fully off and I'm not tempted to change the battery yet.

While running the light stays green even if I have main beam, GPS & heated grips on. This is - if nothing else - comforting to see

I am certainly satisfied that it has been a good & useful purchase.

 

[Nick V]

Easy check.... voltage at all revs above tickover 13.8 or 13.9 volts. Voltage at tickover 14.1 volts. Yes tickover is a bit higher and this is how the regulator works.

QUOTE (Tunneruk):
Be aware, if the battery is on it's way out then it will suddenly just fall off a cliff. You'll go to the bike one day, possibly having just ridden it somewhere and it'll be dead!

I had exactly this happen once on my old F800S. The bike ran perfectly, getting to the other side of Johannesburg. I parked it outside a coffee shop, switched off and went in.
Two hours later, came back and switched on the ignition. Dead. No instrument, no starting.
I tried push-starting the bike on a nearby downhill, even though I wasn't expecting much joy - I knew from experience with my K1200S that CANBUS BMWs behave like spoiled brats when their batteries aren't in perfect condition. Sure enough, nothing.
I was in a shopping mall at the time. After some sweet talk at their hardware store, I borrowed a T25 Torx to get the top panel off, and some jumper cables. To my surprise (and consternation), jumping the battery did not work, either!
Even more luckily, I had a spare, freshly-charged 14Ah battery at home (which almost certainly saved me a call to a towing company).
I got my lady to hop in her car and bring it out to me, along with a 10mm spanner for the battery cable screws.
The 'new' battery went in, and the bike fired up immediately.

 

[timbox]

QUOTE (Tunneruk):
Be aware, if the battery is on it's way out then it will suddenly just fall off a cliff. You'll go to the bike one day, possibly having just ridden it somewhere and it'll be dead!

I had exactly this happen once on my old F800S. The bike ran perfectly, getting to the other side of Johannesburg. I parked it outside a coffee shop, switched off and went in.
Two hours later, came back and switched on the ignition. Dead. No instrument, no starting.
I tried push-starting the bike on a nearby downhill, even though I wasn't expecting much joy - I knew from experience with my K1200S that CANBUS BMWs behave like spoiled brats when their batteries aren't in perfect condition. Sure enough, nothing.
I was in a shopping mall at the time. After some sweet talk at their hardware store, I borrowed a T25 Torx to get the top panel off, and some jumper cables. To my surprise (and consternation), jumping the battery did not work, either!
Even more luckily, I had a spare, freshly-charged 14Ah battery at home (which almost certainly saved me a call to a towing company).
I got my lady to hop in her car and bring it out to me, along with a 10mm spanner for the battery cable screws.
The 'new' battery went in, and the bike fired up immediately.

Your not wrong there Nick, Ive even known Canbus bikes to cut out while riding on a motorway, all down to a duff battery.