Don't let your battery run out of power while your car is left unused'

Looking to head away for an extended holiday, or simply have a need to be without your car for a few months?

Disconnecting the battery in the hope it's a simple exercise to reconnect and restart the engine when required or, in a worst-case scenario, arranging a jump start and hope the battery will recover over time, or after a long run, are options many take.

All of the above should be avoided, especially so for later model vehicles which have on-board computers and fuel-injected engines, which pretty much makes up most of the fleet on our roads these days.

If a vehicle is stored and not driven for a period of time, the battery will slowly discharge because of two factors.


First, the internal resistance within the battery will slowly discharge itself over time. Secondly, if still connected the computer will still place a continuous small drain on the battery even when the vehicle's ignition is switched off.

A flat or disconnected battery can cause other issues and frustrations as well.

For example, if the stereo has a built-in anti-theft security code then that will need to be entered back into the unit before it will work (and how many owners know what that number is?) while in some other cases on-board computers may need to be reset to ensure optimal performance from the engine, transmission and some electrical functions.

To avoid all the hassle it's simply best to leave the battery connected and invest in a multi-stage battery charger which is able to charge and maintain the battery in a fully charged state.

Unlike an old-fashioned battery charger, a maintenance or float charger can stay connected indefinitely without causing any damage to the battery itself.

On the flip side, a maintenance charger should not be used to charge a flat battery. Its main purpose is to maintain the charge and not allow the battery to go flat.

Bill Keane, the projects manager for AA Battery service, and a man who has been in the battery side of the motoring industry for more years that he would care to remember, has a strong and clear message.

"To maximise battery life and performance, lead acid batteries should never be allowed to run flat," he says. "If the vehicle is to be left for an extended period, it should be connected to a multi-stage battery charger which is able to charge and maintain the battery in a fully charged state."

As the modern fleet becomes more and more reliant on electronic wizardry to operate a host of different driving aids and comforts, it's important the battery stays connected and in good condition. And it's a nice way to return home, after all - simply disconnect the maintenance charger, turn the ignition key and you're away.

The average cost for a maintenance charger is around $150.

To find out more about maintenance battery chargers, talk to your local auto electrician/garage or contact AA Batteries on 0800 560 060 during normal business hours.