One of the most common winter calls that tow truck companies get will be a dead battery. With the number of electrical and hybrid cars on the road increasing, the degradation of batteries in cold weather is becoming a much larger problem. The problem is that many people do not know what it is about the cold weather that negatively affects the performance of batteries and kills off older ones.
Cold Temperatures Slow Chemical Reactions
All batteries will rely on chemistry to work correctly whether they are lead-acid, lithium polymer or nickel-cadmium. Batteries are made up of a cathode, an anode, electrolyte solution, collector, and separator. Without going into too much detail, a freeing of electrons will create a current which only occurs through an electrochemical reaction relating to the cathode and the anode in the electrolyte solution. The problem is that cold temperatures will slow this reaction.
There are 2 interrelated problems that all car batteries will suffer from and they are sulfating and undercharging. With sulfating, the sulfate from the acid solution in the battery will coat the cell plates and this will interfere with its ability to hold and release electricity. Undercharging can be caused by too many short trips, a dying alternator, a faulty voltage regulator or your battery not getting enough energy when the engine runs. When this happens a memory effect will develop.
This means that the deepest parts of the sulfate is not being dispersed into the electrolyte solution. This will compromise the ability of the battery to fully charge. All of these issues will be exacerbated by cold weather, particularly in an older battery. Older batteries will already start to lose their efficiency because of the continuous use.
If you do not want to call a tow truck when your battery dies or when your car will not reliably start, you could try two things. If your battery is older than 4 to 5 years, you need to replace it. If you have a newer battery and have issues, you need to get a battery warmer. These items are relatively cheap when you compare them to being stranded and needing to call a tow truck.
If you cannot take either of these steps, you need to know a high-quality roadside assistance company. They will be able to help you when your car will not start because of a dead battery.