BMW R1200RT/R1250RT Forum

A while ago I got caught in a thunderstorm on my 2007 R1200 RT (a little hail just for fun) and when I got home I failed to shut the ignition down. When I went to go for a ride a week later the battery (lithium ion) was completely dead and would not accept a charge. After replacing the battery everything appears to work correctly until I press the start button, then everything shuts down. Power will come back up if I disconnect and reconnect the battery, but everything shuts down again when I press start. I have checked the OBD and there are no trouble codes set. I would very much appreciate any ideas as to what could be wrong or checks I can run.

Sounds to me like a dead battery. Just because it's new doesn't mean it will be fully charged.
Hopefully it's that simple

Hi, thank you for your response. I charged the battery before using and it reads a full 13.8 volts. Any other thoughts?

Everything shutting down when you press the start button could be dodgy switch gear - has been known:-). If it was switch gear, normally turning the ignition off and on again would be enough, so that is a bit confusing! It is weird you need to disconnect the battery to get it to come on again... Unless doing so fixes a poor earth connection or something simply through the movement of cables? I don't know enough about lithium ion batteries in old bikes, but did you have an old lead-acid battery you could test? Peter

Hi,

Perhaps a short circuit starter. When you turn the contact on, does the road light come on ?
If yes, I will verify the starter circuit .

Good luke

Hi,
Thank you for the responses. The running lights come on when I turn on the ignition switch, but after pressing the button to crank the engine there is just a click and everything shuts down. Turning the ignition switch off and back on will not reset it. It only resets (turns on instrument panel and running lights) when I disconnect and reconnect the battery. Do you still think this sounds like the starter circuitry? I am reluctant to strip off all the bodywork to start testing circuits if it is probably in the switch gear. Your suggestions are greatly appreciated, thank you.
Best regards,
Giles

Giles wrote: ↑Mon Jul 31, 2023 5:51 pmAfter pressing the button to crank the engine there is just a click.

Where is the "click" coming from.

Have you tried a drop test on the battery?. Your battery may be showing 13,8v but your type of battery is known for a cell that does not fully charge. The cells may need syncing. You need a special charger to do this. Look on YT there is a few videos with people that had problems with their batteries and how to fix them.

Are you certain that the battery and cables are making a good connection?

As already explained, I think that the "clic" is the starter relay. And after they are two possibility :
1 - Battery dead or bad connexion look at the connectors
2 - Starter relay death (the contact is bad but the coil is OK)

Good luke

The starter relay is under the seat and the solenoid is part of the starter motor.

David. wrote: ↑Thu Aug 03, 2023 10:44 am The starter relay is under the seat and the solenoid is part of the starter motor.

Hi
When you push on start buton, to try to find where come the "clic"
solenoid of starter ?
It not, you can test your battery with => https://fr.aliexpress.com/item/10050055 ... pt=glo2fra
This product contrl the internal resistor of your battery and give you a clear information about the health of your battery.
After, if you hear that is the solenoid of the starter, I thing that origin of your default is the starter but before to change it try to repare it.
In my country, I can find electric motor repairer who is able to find a solution perhaps without spend a lot of money.

You can put your test meter on the battery and read the voltage, leave it connected and press the start button.
If the battery has a dead cell the meter will drop to single figures and stay there when you hear the click. Take your finger of the start button and see how long it takes the battery to recover back to it's start voltage.

The other thing I'd try after that is just a set of jump leads from either another battery or car (don't have the car running) and see if the bike fires up straight away.

These are simple things to check prior to taking all the plastics off or the switch gear apart.

Happened to me on a bike I just bought, day after I brought it home from the dealership. 2010 model. started off by just clicking when starting but when I took the battery out to charge and put it back in it shut off the system entirely. Turned out it was dirty connections on the battery. Cleaned the posts and cable-ends and it started up. Maintainer even said it failed the cycle 3 times in a row, but then eventually passed. I guess the connections were connected in an oh-so finicky way that it was able to stay on but not have enough voltage to start, and when it was removed it was gunk on live connections that shorted out the system.

If your connections are clean then it may be a connection nearby a bit down the line before it is distributed through the system.

Im still replacing the battery just in case (and because the dealership is replacing it for free).