Quite Alarm Noise, Is this a low battery alarm?

[flanok]

I have brought the car out of the garage after a winter lay up and it has reminded me of an issue I have had with my Porsche Boxster since I got it last year.

1999 Boxster 2.6 (996)

Every now an again I get an alarm sounding for about 2 to 3 minutes.

This is not the main intruder alarm, but quieter.

I am sure I figured out or was told, it is an alarm that sounds when the bettery is low?

Is this true?

I have replaced the battery and the alternator has been checked as OK, so dont understand why this alarm would sound after I have charged the battery (albeit no to full charge), or when the engine is running.

Can someone confirm this is why this alarm is sounding and if I am correct about low battery, point me to any posts of information to track down any faults or likely causes to draining the battery.

Thanks

[logray]

Hello

Low battery could be one of the reasons why this might occur.

One thing to check for might be the codes or pending codes from the alarm unit (requires Durametric, PST2, PIWIS), to see if it detects any faults in the system or see where the last alarm was triggered.

Another possibility could be water damage to the alarm unit under the seat

GL

[flanok]

thanks for the reply.

I dont have a diagnostic machine, so will try alarm unit under seat first.

Would this drain battery?

I premume I would just be looking for dampness etc.

Which seat is it under? Uk car.

Thanks

mark

[Loren]

Under the left seat on all cars.

[flanok]

It all is very clean and dry, so dont think it is the alarm under seat.

Thanks

[wvicary]

This alarm sounds when the vehicle is running or driving? It's not the gong for the speed alert you're hearing is it? The UK vehicles have a separate alarm siren with battery back up then what we have here in NA.

[flanok]

Thanks for the reply

The alarm does sound (very quietly) for about 2 minutes after starting the engine and I can drive it Ok with the alarm sounding, but it is continous whether I am stopped, driving at 5mph or have had time to build up speed.

It then switches off after about 2 minutes.

You say seperate alarm battery back up?

I wonder if this has gone flat or needs replacing?

The car normally will drain its main battery after a few days, but this weekend I locked the car using the key only not the alarm button.

I have started it up this morning. (wednesday night to Sunday morning and it fired staight away with no quiet alarm sound).

It all points to the alarm now, both for the sound and draining the battery.

I suppose I need some advice how to check battery or what to do next

Thanks Mark

[wvicary]

Have the vehicles battery tested and charging system. The UK security alarm siren has a back up battery that I believe is integral to the siren. I have read reports that they can be damaged from water ingress. I think you can easily disconnect the siren which is located in the front cowl area under the windscreen wiper area on the left if memory serves.

[flanok]

it has a new battery and chargiing has been tested.

The area under the seat seems very clean and dry, but I haven't taken the seat out to gain access to the alarm.

I presume I would have to this.

But everything points to the alarm now.

[2007 Boxster]

Having the same issue did you solve it?