Ask an expert

I have a Saab Aero which has lots of things controlled by computer. If the battery goes flat, or if I disconnect the battery, will this affect the computers? Also, if the battery goes flat, will it trigger something and set the burglar alarm off?

Often on-board engine management systems need to go through a re-learning phase when the battery is disconnected/reconnected.

This can affect electronically controlled components such as automatic transmissions and power windows. You would need to either read the owner’s manual if possible, or make contact with a Holden Dealer (they were the agents for this brand in NZ) to seek specifics relating to your model.

The re-learning can take place automatically over time, or by carrying out certain instructions and procedures specified by the manufacturer.

If you plan to leave the vehicle idle for some time it would be wise to consider buying a battery maintenance charger which will remove the risk of running the battery flat and incurring unwanted problems.

These charges simply monitor the battery voltage and will top it up as required. People who store cars and boats for long periods use these types of charges.

The maintenance chargers will be available from select auto electricians, automotive stores such as Repco or the AA Battery service (0800 500 222 and ask for battery service).

If the alarm fitted to your Saab is an aftermarket unit with a back up battery fitted in the siren, it could be activated by a disconnected or flat battery.