How to Extend the Life of the Car Battery
Car batteries are still mostly lead-acid batteries, designed for strong power surges, required when cranking the car's engine.
On average, car batteries last 2-5 years, although there are examples of good, well-maintained batteries that lasted longer, much longer. So, what's their secret?
Updated: January 14, 2022.
What Kills the Car Battery?
The main reasons why car batteries die are:
- heat: Most cars have batteries near engines, in order to have starting cables as short as possible. This also means that as soon as the engine is warmed up, the battery is also pretty warm.
And, during summer, this means that the battery is "cooking" at rather high temperatures, sometimes for hours each day.
- low electrolyte levels: lead-acid batteries feature electrolyte that consists of water and sulfuric acid - as the water evaporates because of heat and/or battery gassing, the level of electrolyte in the battery cells drops and at a certain level can cause issues with the operation of individual cells and in the end, the whole battery.
- over-discharging: car batteries are designed mostly as starting/cranking batteries and discharging them below a certain level can shorten their operating lifetime. Also, in order to improve fuel economy, some cars feature a "Stop and Start" system - when the car stops, for example, at red traffic lights, the engine is automatically stopped and when the car needs to go, the engine is automatically started. While the engine is turned off, the battery powers all of the lights and electronics AND it needs to crank the engine over and over - some batteries are designed for such heavy-duty use, but some are not ...
- vibrations and mechanical impacts can physically damage the battery and shorten its operating lifetime - the battery can lose the electrolyte or the battery plates can come in contact, short-circuiting the battery cell(s).
- corrosion of the battery terminals due to the fumes exiting the battery can increase the electric resistance between the battery terminals and cables, forcing the battery to work harder than it should, again, shortening its operating lifetime.
How to Prolong The Car Battery Life?
There are several things the driver can do in order to prolong the car battery life, including:
- if You have a wet/flooded lead-acid battery, check the electrolyte levels periodically, especially during summer, and add distilled water as needed,
- check the battery terminals for signs of corrosion and if required, clean the battery terminals from corrosion,
- during summer, if possible, always park the car in the shade. This can significantly decrease the battery average temperature.
- if You are not going to use the car for some time, for example, few weeks, it is a good idea to connect the car battery charger/maintainer to the car's battery in order to keep the battery fully charged.
Note: some cars don't allow the user to attach the battery charger/maintainer to the car battery due to issues with certain battery charging phases, like cell equalization - check the car's Owner's Guide/Manual if it is allowed to connect the battery charger/maintainer directly to the battery while the battery is still connected to the car's electric system.
- periodically check the battery voltage and if needed either recharge the battery using a dedicated car battery charger or take the car for a longer drive (1-2 hours, at least).
- avoid short drives as much as possible, especially if the "Stop and Start" system is present. If there are issues with the battery charge, temporarily disable the "Stop and Start" system, drive the car for some time (1-2h) and check the voltage. If the alternator is unable to keep the battery charged, take the car to the workshop and let them verify the charging system and the battery itself.
- avoid using multimedia systems, lights, and other loads for a longer period of time while the engine is off.
In short, keep the car battery as cool as possible and as charged as possible and the battery will operate properly for a long time, often longer than the warranty period.
And even then, it is sometimes difficult to foresee when the battery will die - just in case, keep a set of good car jump cables in your car.
Also, a good lithium car jump starter can come in very handy.