As winter sets in and the weather gets colder, we get lots of calls and questions about how our batteries perform in winter weather, and what steps need to be taken to maintain them. ALL batteries will perform poorly in cold weather, regardless of whether they are lithium or lead-acid. In fact, a lithium battery will still outperform a comparably-sized lead-acid when the temperature drops. However, since most people try to run the smallest and lightest lithium battery possible, there are some things to be aware of: For a daily-driven car… …almost no extra effort is required. On a very cold morning, however, one might find that the cranking performance of the battery is not as strong as usual; if it is very cold and the car has been sitting for a while, the car might not crank fast enough to start. This does not mean that your battery is dead.
This we only be necessary at very low temperatures, and we have found that after doing this once on cold mornings, the battery stays warm enough to crank the engine reliably for the rest of the day. This trick will only work if the battery is close to warm enough to start the car–if the battery is too cold, or too small, then you will need to warm the battery up before use. For racers who store their cars in the off-season… …the battery only needs to be monitored to make sure it is never completely discharged. Handily, lithium batteries self-discharge at a much slower rate than conventional chemistries.
On cars that see infrequent use during the winter… …it is even more important to keep the battery charged up, and the car will draw a small amount of energy from the battery to do things such as keep the radio presets, or to provide power for the alarm system. Some cars, such as later-model Porsches and BMWs, have a much higher draw than other cars, and will thus drain the battery much more quickly. Every car is different.
Some other items to note: