The Neighbourhood Mechanic: Cold saps battery power
Modern batteries rely on a chemical reaction in order to produce power. Colder temperatures have the effect of slowing down this reaction, resulting in a dramatic drop in the power available to start your car. If you need or are giving someone a boost here are some rules to follow to do it safely.
First off leave the boosting car running. Flip on the lights on the vehicle that's dead to avoid a power surge and hook up the cables. Make sure that the last connection is at running car. Reason? Dead and frozen batteries have a tendency to explode and you want to be as far away from that possibility as possible. Once the vehicle starts, let it run for a few minutes before disconnecting, this will allow the voltages to equalize. Next step? Have the charging system checked.
Q. Can you help me? I needed a boost on my 1999 Honda the other day. I connected the cables the wrong way and there was a terrific spark. Now everything is dead. I know I blew something. What can I expect as a repair bill?
A. You have reversed the polarity of the batteries when you hooked up the cables. If all you experienced was a spark you were lucky. Many times reversing the polarity will cause the battery to pop. Honda's like many modern vehicles have the main power cables fused. When you describe that everything is dead, more than likely all you did was blow the main fuse. Just locate it in the under hood fuse box and swap it out. Vehicles not equipped with this feature may suffer computer damage when polarity is switched. Be more careful if there is a next time.