How to make Li-ion batteries last longer
The first thing you should do is to avoid letting your battery get hot. Fortunately, many electric vehicles go part of the way there. Tesla’s vehicles and the Chevy Bolt/Volt all use active cooling to keep the battery from overheating, though the Nissan Leaf relies on passive air cooling to keep the battery cool, making battery heat an even larger factor for those vehicles.
The bigger heat issue that you have more control over is heat during charging. Even for cars with active battery cooling, the battery still heats up considerably during charging, especially when charging at high rates or supercharging. While supercharging is convenient when you need to get back on the road quickly, it is terrible for battery life if performed often. To make your battery last as long as possible, you should try to charge at lower rates, which keeps the battery cooler and happier. A longer charge each night is much better than supercharging over lunch each day.
Next, you should aim to charge to lower levels when possible, especially if the car will be resting for a long period of time. While it may be comforting to see your battery meter read “100%”, your battery will be anything but comfortable.
Charging to a level below 100% can have a large impact by reducing the rate of degradation of the battery.
Most people don’t use their entire electric vehicle battery pack capacity every day, and rarely have the need to charge all the way to 100%. By charging a lithium-ion battery to 80%, the lifetime of the battery can be as much as doubled, according to Grin Technologies. This Canadian company performed such tests while developing an adjustable charger designed for electric bicycles and other light electric vehicle batteries.
It is important to note that the most damage from high charge levels comes from when the battery rests at such high levels for long periods of time. I’ve heard of many people who freak out after learning about the effect of high charge levels, with some swearing off 100% charging forever.
But 100% charging isn’t a big deal in small doses. If you are planning a long trip and will be heading out shortly after you finish charging, a 100% charge will have very little impact on your battery’s lifespan. However, if you will be leaving your battery unused for many days or weeks, a charge level of between 30-60% is much healthier for the batteries over the long-term.
Fortunately for us, both of these factors can be controlled to make batteries last as long as possible. The following simple steps can be taken to drastically increase the life of nearly any lithium-ion batteries.