Not used the 4.2 SC for a couple of weeks and discovered today that the battery has gone very flat – down to 3.3 V.
Halfway through recharging it the alarm starts going off and neither of my key fobs will turn it off.
It's the bleeping alarm rather than the continuous siren and the indicators do not flash. It stops of its own accord after a few minutes.
Could the battery be knackered and won't take the charge?
How do I stop the alarm going off? 2006MY 4.2 SC
BMW R1250 GSA Rallye TE
Triumph Tiger 1050 (sold)
1979 Pontiac Trans Am (sold)

Is your bonnet ajar? The bonnet sensor sets it off.

If it is ajar you can hold down the button (it is on the offside towards the windscreen near to the brake fluid top up) with some gaffa tape or something.

If it is closed sometimes it need a hard push, or some folded paper over that switch to make sure it is closed

or just unplug it

Thanks guys, I did unplug it but it made no difference. I'm guessing that the battery is so deeply discharged that it wouldn't take a charge so the alarm was going off as if the battery had been disconnected.

I hooked up a power pack to the battery terminals and after a while was able to start the engine. I left it connected overnight with the doors/bonnet unlocked and it was OK. It was getting on for midnight so I didn't want to risk trying to lock it and have the alarm going off again.

I'll check the voltage when I get chance later this morning but I reckon I'll be forking out for a new battery. 2006MY 4.2 SC
BMW R1250 GSA Rallye TE
Triumph Tiger 1050 (sold)
1979 Pontiac Trans Am (sold)

Mulcher, you said “halfway through charging the alarm went off”. Are you charging with the battery still connected? I was told years ago that traditional battery chargers can damage alternator diodes and other sensitive electronics. I don’t know this is fact and I’m not suggesting you have caused damage but disconnecting the battery might be a sensible precaution.
I’ve just shelled for a new alternator on an L322 with a history of battery drain and battery charging, it wasn’t cheap! The alternator wasn’t the cause of the drain and it’d only done 70k miles so something had damaged it.

Charging a battery whilst still connected to the car does divide opinion sometimes. Last year I searched the forum and found that most owners seemed quite happy to charge in-situ with the CTEK charger.

In the workshop manual, Battery-General section, I found the following:

Quote:

"Trickle charging (defined as voltages <16 volts) may be carried out with the battery connected. Make sure that
the battery terminals are fully tightened prior to trickle charging.
CAUTION: Boost charging may only be carried out with the battery disconnected from the vehicle."

Yes, fuse 12 hvac. Official wiring loom fixed it but now switching on the driver seat heater causes the loom relay to switch off dropping out the seat heater and hvac. The relay then re-engages restoring the hvac but not the heater. Indy is chasing an answer from LR tech.