Timely advice from Haynes’ Technical Editor Is your battery going to let you down this winter? | | Fact: car batteries are affected by cold weather. Although it’s relatively mild at the moment, winter will be in full flow soon and many of us are likely to see frost, hail, sleet and even some snow.
With the headlights in use more often, the heater blower motor running, heated seats doing their thing and the heated rear screen on, it’s a good idea to keep your battery in the best of health.
The first thing you can do is remove any battery cover, then use a soft brush (the type that comes with a dustpan) to clear away any dirt or debris from the top of the battery, particularly around the battery terminal posts. A layer of rotting leaves or similar will retain moisture and could cause a current drain. | | | If the connections to the battery look corroded, as shown above, carefully pour a little boiling water over the terminals and the corrosion should dissolve. Obviously, you need to be careful when doing this, so wear gloves and go slowly – only a small amount of water is required.
Once any corrosion has been removed, check the security of the connections and apply a thin layer of petroleum jelly. This should keep the connections watertight and prevent any more corrosion from forming. | | The days of removing the caps and checking the electrolyte level within the battery cells are long gone. Batteries are now ‘maintenance-free’; so as long as the casing isn’t cracked, the electrolyte level should be fine.
Most modern vehicles have a charging system that is more than capable of keeping the battery in a good state of charge in the winter, providing the alternator drive belt is in good condition and the alternator is working properly. Your manual will tell you how to check and, if necessary, renew the belt.
Keeping the battery in a good state of charge gives you confidence that on a cold, frosty morning, when the key is turned, the engine is going to start.
I own a few vehicles, some of which don’t get used every day. So I tend to keep an intelligent battery charger connected to one in the garage, and plug a small solar charger into the diagnostic socket of the one parked outside. One of the pins of the socket connects directly to the battery and one to earth. So the solar panel sits on the dashboard and trickles charge through the socket and into the battery.
If a turn of the key produces the dreaded ‘click’ or turns the engine over really slowly, the chances are that the battery has lost its charge and is flat.
Years ago, I would have tried to bump-start it, with an assistant giving the car a push. However, with the introduction of catalytic converters in the ’90s, this is no longer recommended. Any unburnt fuel going through the engine into the exhaust system could damage the converter and cause a hefty bill. | | | Technical Editor, Martynn Randall has been with Haynes for 27 years and has written more than 60 Haynes Manuals. | | | | | | |  |
