Battery removal help

UK forum for general and technical discussion about the Z3 roadster
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jonnyZZZ
Joined: Sat 14 Oct, 2017 09:13
Posts: 3

  Z3 roadster 1.9

Battery removal help

Post by jonnyZZZ »

Hi I want to remove the battery for the winter but when I disconnect a terminal the alarm goes off :( is there a way of stopping this please.
therealdb1
Joined: Tue 25 Jun, 2013 21:47
Posts: 263

  Z3 roadster 2.0

Re: Battery removal help

Post by therealdb1 »

Is this a factory fit BMW alarm?
With the lid open to disconnect the battery the alarm will not be armed so it shouldn't be triggered.
If it is an aftermarket one you'll need to find where it gets its back up supply from and disconnect that.
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Robert T
Site Admin
Joined: Mon 12 Jun, 2006 10:35
Posts: 10170

  Z3 roadster 1.9
Location: Cheshire

Re: Battery removal help

Post by Robert T »

Hi Jonny and welcome to the forum.

I see that you have a 1997 car, so if it has the original alarm, it will the type with the separate fobs and a little round key.

The alarm siren has a backup battery, which causes the siren to sound if the main battery is disconnected.

The little round key can be inserted into a key switch on the siren and turned to disable the siren.

Cheers R.
Arctic Silver '99 Z3 1.9 & Black '59 Frogeye 1275cc
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jonnyZZZ
Joined: Sat 14 Oct, 2017 09:13
Posts: 3

  Z3 roadster 1.9

Re: Battery removal help

Post by jonnyZZZ »

Robert T wrote: Wed 13 Dec, 2017 18:33 Hi Jonny and welcome to the forum.

I see that you have a 1997 car, so if it has the original alarm, it will the type with the separate fobs and a little round key.

The alarm siren has a backup battery, which causes the siren to sound if the main battery is disconnected.

The little round key can be inserted into a key switch on the siren and turned to disable the siren.

Cheers R.
Thanks Robert for the input. In the last 20 years keys seem to have gone missing as I do not have a remote key or separate fob, the central locking works ok off the door/ignition key, I don't actually know if a remote system was fitted to all early cars, so I think I need to delve a little into the alarm system. Through lack of garage space it is having to spend the winter outside but covered over and just want to keep the battery in the garage and charged up, I do this with another car I have. Further investigation might have to wait until after Christmas.
Jonco
Joined: Sat 04 Jun, 2011 07:24
Posts: 402

  Z3 roadster 1.9
Location: Cheshire

Re: Battery removal help

Post by Jonco »

jonnyZZZ wrote: Thu 14 Dec, 2017 07:28 Thanks Robert for the input. In the last 20 years keys seem to have gone missing as I do not have a remote key or separate fob, the central locking works ok off the door/ignition key, I don't actually know if a remote system was fitted to all early cars, so I think I need to delve a little into the alarm system. Through lack of garage space it is having to spend the winter outside but covered over and just want to keep the battery in the garage and charged up, I do this with another car I have. Further investigation might have to wait until after Christmas.
Agree with Robert - the back-up for the original alarm has limited capacity and will drain in a short period after disconnection if you can put up with the noise. If you look in the right side of the engine bay you will be able to see the siren if it's an original. I have a photo but unable to load it on here.

EDIT Have a look at viewtopic.php?f=5&t=45506 for picture of original EWS siren.
jonnyZZZ
Joined: Sat 14 Oct, 2017 09:13
Posts: 3

  Z3 roadster 1.9

Re: Battery removal help

Post by jonnyZZZ »

Thanks guys for the input. I presume that when the battery is reconnected the siren will re charge, not that anyone would take any notice of it, its not exactly deafening :lol:
Jonco
Joined: Sat 04 Jun, 2011 07:24
Posts: 402

  Z3 roadster 1.9
Location: Cheshire

Re: Battery removal help

Post by Jonco »

jonnyZZZ wrote: Mon 18 Dec, 2017 15:34 Thanks guys for the input. I presume that when the battery is reconnected the siren will re charge, not that anyone would take any notice of it, its not exactly deafening :lol:
Yes it recharges on re-connection - have done it several times on mine but admittedly only for a few days at a time - you could consider a ctek trickle charger if you can run a poor supply to the car.
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