Just a quick question... Hope it des not sound too stupid

The battery in my 03 WRX has gone flat once and I get the occasional chirp from the alarm on startup.
Probably due to the fact I'm working at home at the moment and therefore don't use the car as often as I used to.
I have the pioneer AVIC-X1 that can display 'vehicle dynamics' like acceleration, speed, direction, and VOLTAGE etc.

I was wondering how the readings on the Voltage gauge would change if the battery was run down so I could monitor the situation a little better.

Thanks in advance

 

Just to confirm that the chirp on start up is normal if the battery voltage falls below a certain level on cranking - the battery siren sees the volt drop and thinks the battery has been disconnected.
If you have the standard fit UK alarm system (with keypad in the coin box to the right of the steering column), you can also check the vehicles battery voltage by turning the ignition on, press 8 on the keypad and then turn the ignition off within 5 seconds. The dashboard LED (to the left of the clock in the centre binacle) will then flash back the battery voltage ie 10 flashes = 10 volts - just thought I'd mention this as it will probably draw less current than powering your pioneer display up.
Unfortunately the system requires 12v to operate accurately and so once the vehicles battery voltage falls below 8v the reading could be inconsistent - this may also apply to your Pioneer unit.
I've seen other posts regarding flat battery problems, and an interesting suggesion was to turn the side lights on whilst driving - apparently the vehicle has a "smart" alternator that only charges when it sees current draw - turning the lamps on ensures charging takes place.
SS