BMW R1200RT/R1250RT Forum

Hi all!

On my 2014 R1200RR (LC / K52), I added a USB charging port by repurposing the Hella plug on the throttle side fairing.
I disconnected the wires at the back of the Hella plug and connected a 12v-to-5v USB adaptor.
After completing the instal, everything worked fine so I buttoned everything up and went for a ride.

3 days later, the battery would power up the dash and try to turn the engine over but just couldn't start it due to low power.
There was nothing left connected to the newly installed USB cable during those 3 days.
BTY, the bike's battery was changed less that 1 year ago and has been very reliable so far, no indication of failing or anything lately.

I'm wondering if the small draw of the 12v-5v connector was sufficient to keep the circuit live after the usual 60 seconds after turning the key off?
I vaguely remember reading something of this nature on a forum but can't find it now.

1 last thing that was weird and probably related to the issue: when I turned off the bike with my phone pluged in my new USB port, I saw it flashing the charging / pluged in notification repetedly for a little while. When the engine was running, the phone was charging like normal.

Thanks in advance for any ideas!

Yes, esp. if there was no problem before installing that. Connect a meter (to read amperage) to the battery. Wait a reasonable time for the bike to go to sleep & then read the meter for any parasitic drain. If one present, disconnect your adapter & chk. meter again. There may normally be a small drain; If you have keyless ign. and/or an alarm, for example.

Ok, I checked a little more and it turns out the power is still on on the power socket even with the bike turned off for hours.

How can that be?
Is it normal behaviour on this bike/model?

I have a Motoscan. Is there a setting I can change to tell the bike to cut the power to this circuit when the engine is off?

The power will stay on if there is a lot of draw!

Not sure what BMW's idea was behind this!

So I guess it's back to the drawing board for me.
I just want a USB cable concealed in the left "glove" box of the fairing that's on and off with the engine.
Can't be that hard without resorting to HEX-Can and stuff like that that seams overkill to me?

I just hate untidy cables so using a plug-in Hella-to-usb adaptor is essentially a no-go for me.
Besides, considering what I just discovered, I guess everyone using one of these adaptors also risk draining their battery if they don't unplug the adaptor when the engine is off, right?

Any ideas? TIA!

Try running it off a switched relay off the aux socket

The relay will draw minimal power and should switch off then

Sounds like a good idea.
Hopefully, as you mentionned, it will trick the CanBus.

alexvtr wrote: ↑Sun Oct 15, 2023 8:09 pm So I guess it's back to the drawing board for me.
I just want a USB cable concealed in the left "glove" box of the fairing that's on and off with the engine.
Can't be that hard without resorting to HEX-Can and stuff like that that seams overkill to me?

I just hate untidy cables so using a plug-in Hella-to-usb adaptor is essentially a no-go for me.
Besides, considering what I just discovered, I guess everyone using one of these adaptors also risk draining their battery if they don't unplug the adaptor when the engine is off, right?

Any ideas? TIA!

Do you have the 12v aux connection near the steering head? If so that will do what you want. I used it to power a GPS. Switches off shortly after the ign. is turned off.