Car Care: Avoiding a flat battery

A drained battery usually means waiting aroud for roadside help Picture / Getty Images

Helpful device clicks in before your battery goes dead

Flat batteries are never planned, they usually happen at the most inconvenient time and nearly always involve a fair amount of frustration while owners sit around and wait for roadside assistance or help of some sort to arrive.

Usually it's down to human error, headlights or interior lights being left on, and once the engine is back up and running many drivers are left with the option of either a fairly lengthy motorway run or keeping the engine idling so the battery recovers.

Then there's the well-rehearsed, and expensive, speech from within the industry that suggests the battery may well be reaching the end of its life anyway and for peace of mind replacement is a good option.

So what's the answer to help avoid the dreaded flat battery scenario and to help extend battery life? There is a device on the New Zealand market called PriorityStart! which may well be your lifesaver.

Its job is to monitor battery condition and if voltage drops to a predetermined level (11.7 volts) for one minute continuously and the ignition key is in the off position, it automatically disconnects the entire electrical load from the battery.

Automatic reconnection is made when a load of 0.2mV is placed directly to the battery - such as when the ignition is turned to the start position or by the driver activating accessories such as the headlights or pressing on the brake pedal. Because of the complete battery disconnect, the clock and audio system may need resetting on some vehicles but don't forget that would still apply if the battery was left to drain anyway as would the resetting of any other memory dependent devices.

The unit itself is installed directly on to the positive terminal of the battery. For late model or luxury models we would recommend talking to your vehicle dealer about fitting any such device, to cover your warranty.

On the surface it sounds like an effective way to reduce the risk of experiencing a flat battery due to unintentionally creating an unwanted and long term voltage drain.

When you think about it, it's a wonder respective manufacturers haven't thought about installing similar technology into their vehicles during production. There are three models available in the PriorityStart! line-up suitable for motor vehicles, motorhomes and marine use.

Prices range from between $170 and $190.

Note: PriorityStart! should not be relied upon when vehicles are placed in storage for long periods. In this case it's best to leave the battery connected and invest in a maintenance battery charger which is able to maintain the battery in a fully charged state. They can be left connected indefinitely without causing any damage to the battery itself.

To find out more about PriorityStart! go to prioritystart.co.nz.

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.