How to replace a 2000 Astra car key battery

My car key remote went flat.

This is a major pain when one is used to the joys of remote key locking. Having to go to the door with the keyhole every time and fumble to get the key into it — bleuch.

I assumed that like most things in the world of cars, I’d have to take the key to a dealer and get some kind of specialist to open it up and replace it with a non-standard Holden battery not generally available to the public, all costing a small fortune of course.

I shouldn’t be so cynical.

A little Googling found the solution (with various steps in a couple of different places, so I’m compiling it all here for future reference). It was as simple as:

1. Carefully wedge open the key with a screwdriver

2. Ease out the old battery, and put in a new one (watch battery type CR3032)

3. Put the key back together

4. Resync the key with the car, by turning the key in the ignition (so the lights, radio etc comes on; no need to actually start the car) and press the button on the key. The locks will trigger.