Ask an expert

we are going away for 10weeks and would like to know what is best to do with the car batteries: (1)leave them connected in the car--(2) discontect the terminals and leave them in the car. (3) remove them and connect to a 12 volt battery charger details input 230v 50hz 0.22A 45W . output 12.5Vd.c 2.5 A
thanks

We don’t recommend disconnecting batteries these days as there as so many different scenario’s which can upset the on-board electronics depending on vehicle age/make/model.

For example, there are some electronic transmissions that need to go through a re-learning phase once a battery is disconnected or allowed to go flat. Same for some vehicles with electric windows; they may not work quite the same once the battery is disconnected/reconnected.

For some older vehicles it can be as simple as losing the radio memory which means entering a specific code to bring the unit back to life. Where you get that code from is often a frustrating and hopless task.

The best recommendation is to purchase a unit which maintains a full battery charge if the vehicle is being left for long periods. Car enthusiasts who store their classic/vintage cars for long periods use these types of chargers.

These devices are not like a full-on battery charger which will continuously charge and ‘cook’ a battery if left connected for long periods. Instead, they simply maintain a fully charged and connected battery by topping it up as the voltage drops away.

AA Batteries sell these units in the main centres of NZ (Auckland, Wellington and Christchurch - phone 0800 500 222 for more information). Connection is self explanatory but AA Battery Service staff will provide help and advice as required.

In other regions most auto electricians will sell a similar style of unit. Ask for a battery stabiliser or charge maintain unit.

Costs can vary between $60 and $90.