[marnix]

Hello everyone,
Today I was driving home from school and on the high way I noticed my blinkers stopped working. Eventually the battery light came on on the dashboard. I could hear the bike was starting to struggle to stay on whilst waiting in front of a traffic light. I kept riding and the speedometer didn’t show the speed anymore. At the third red light the bike shut off and now it doesn’t want to start anymore. Now when I turn on the ignition the fuel pump doesn’t make any sound but all the lights turn on. When I try to start the bike it doesn’t crank but it makes a whining noise(steady tone). Anyone know what might be the issue?

 

[bbbelanger]

Battery empty for sure. Charge battery or boost to restart, then diagnose charging system :
bike stopped battery voltage should measure 12.6 volts when fully charged.
Bike running battery voltage should measure 14.5 volts.
Voltages over or under the above are indicators of charging system malfunction.

Check internet for precise howtos, the bikes systems are same as car systems, only smaller in dimension.

 

[ARBOLMANO]

You’ve let out the magical electrical smoke! Hopefully a poor connection, most likely your battery has failed. Less likely but possible your charging system has failed. Start at battery connections, charge/load test battery, start and check for a 2 volt increase from resting voltage. There is a voltmeter built into the screen. The warning lamp fires when your volts drop below 12 meaning failure soon. For many, the lithium batteries are a good replacement.

 

[hasselman]

And the most obvious to check first: Is both battery connectors tight?
It's easy to forget the easy things

 

[marnix]

Okay so I just put in my old battery. I haven’t used it in a few months and didn’t charge it before so maybe that has an effect on the results. The battery reads 12.5V before turning the bike on. When I turn the bike on it drops to around 11-11.4 and after a little bit it goes to 11.6 and stays there for the few minutes I left the bike running. Any thoughts?

 

[Cyrille]

Get a new battery!

 

[marnix]

Get a new battery!

The one I just took out is a yuasa ytx9-BS that’s only a few months old. The old battery I put in was unnecessarily changed and only used for 3000km. Is a new battery really necessary?

 

[Cyrille]

If your bike is left unused for a few weeks or even months you should consider the purchase of a permanent charger i.e. a charger that is connected to the bike 24/7 and maintains the battery in top condition. For example: Tecmate Optimate 3.

The charger will prevent the battery from getting damaged and will simulate charging cycles. To connect it to the battery you may install a permanent connector such as Optimate O-1 with an SAE plug or battery clamps.

 

[marnix]

I actually own one but since I just moved places I didn’t have it with me. I only left the bike unused for half a week and rode to school on it in the morning for about 45 minutes with no issues. On the way back after about 35 minutes is when the issues occurred.

 

[ARBOLMANO]

Hmm so with the bike running, your battery voltage stays the same or goes lower? That’s something amiss. If you’ve already tossed a battery at it then you’ve charging system errors.
At this point, out of in-experienced hands. Time time go see a professional. doesnt need to be BMW dealer unless your still under warranty

 

[OldBiker]

I think your problem is the Stator in the charging system is a known problem this video shows exactly the problems you are having with your battery voltages.

 

[marnix]

Just went for a ride. The battery light came on after about 30 minutes so I returned home. When I turned the bike off and tried turning it on again it doesn’t turn on anymore. I’ll try to find a shop nearby to get it fixed.

 

[marnix]

Just went for a ride. The battery light came on after about 30 minutes so I returned home. When I turned the bike off and tried turning it on again it doesn’t turn on anymore. I’ll try to find a shop nearby to get it fixed.

Also the abs light turned on 10 minutes before the battery light came on. Is this related or is that something else?

 

[ARBOLMANO]

Yeah the ABS will flag as inoperable with insufficient voltage. Be prepared, this is not an inexpensive repair situation.
Good luck.

 

[marnix]

Yeah the ABS will flag as inoperable with insufficient voltage. Be prepared, this is not an inexpensive repair situation.
Good luck.

Any rough indication on the costs? And thank you

 

[GermanMachine]

Does the bike have the newer style Alternator Stator? If not, sounds like the classic flywheel rotor bolts backing out and damaging the stator windings. Even with a bad battery, once the engine is running you should see above 13 volts if the charging system is working properly. It is a pretty common issue that BMW provided parts for when it occurred on mine.

 

[marnix]

Does the bike have the newer style Alternator Stator? If not, sounds like the classic flywheel rotor bolts backing out and damaging the stator windings. Even with a bad battery, once the engine is running you should see above 13 volts if the charging system is working properly. It is a pretty common issue that BMW provided parts for when it occurred on mine.

How do I know if it has the new or old stator?

 

[GermanMachine]

How do I know if it has the new or old stator?

What year is your bike and do you know it's maintenance history since new?

 

[marnix]

How do I know if it has the new or old stator?

August 2018. As far as I know stator is still the same.

 

[ARBOLMANO]

Hard to estimate costs until a complete diagnosis completed. The Gods may smile upon you and it just be a connection. Or complete stator and rotor assembly for like $1000. Get thee to a technician and end speculation. Riding season here.