Will EV Batteries Last Long?
Potential EV buyers often have doubts about the longevity and safety of EV batteries. These doubts are understandable, after all, EVs and smartphones use the same lithium battery technology and anyone who has a smartphone would have experienced battery problems with their devices over the years.
But do batteries in EVs deserve the reputation that smartphone batteries have?
Let us dig a little deeper. Before we begin, there is no getting around this: batteries will degrade and will have an end-of-life. But when and how are the important questions.
Tip: Read here for an in depth look at the technology behind EV batteries.
Designing Long-Lasting Batteries
It is true that smartphone and EV batteries use the same battery chemistry and therefore it is natural to think that they have the same apparent obsolescence. The longevity of a battery depends on a range of factors such as temperature, discharge-charge cycles, and usage/charging patterns, all of which ultimately affects the battery on a microscopic level leading to shorter runtimes/lower capacities and EV batteries are no different in this respect.
Crucially, battery longevity can be engineered by using different materials or by fine-tuning the component mixture in battery chemistry. And this flexibility has allowed EV battery manufacturers to maximise the longevity, unlike consumer-grade lithium batteries used in smartphones where lower costs are a driving factor.
Most EV batteries use (with some slight tweaks) lithium nickel manganese cobalt oxide (NMC) which has a much better lifetime than lithium cobalt oxide (LCO) used in smartphone batteries while forgoing some energy density. Tesla may also start using LFP (lithium iron phosphate)-based batteries, forgoing some amount of capacity for significantly improved longevity and at a reduced cost. Additionally, EV manufacturers often guarantee their batteries for at least 8 years which means that you should experience the same range from a full charge throughout.
Prolonging Battery Life Made Easy
Apart from designing batteries to be longer lasting, EV battery manufacturers are using their knowledge of how batteries degrade to prolong their lifespan. This includes constant charging/discharging, fast discharge (e.g. accelerating all the time), high temperature, mechanical shocks, and complete discharge and fully charged.
Do not let this scare you into thinking batteries are fragile!
Thankfully, modern EV batteries are ‘smart’ and have an in-built battery management system (BMS) to capture critical data about battery use patterns and prevent any abuse. The BMS controls each battery cell to prevent complete discharge, and it controls the charging to prevent overcharging—giving an operating limit of 30% to 80% of the battery capacity (which is why 30-80% charge times are always listed) and prolongs your battery life.
The BMS captures the state-of-charge (SoC) of the battery which is translated to the battery level indicator that you see. This is used in diagnosing the health of the battery or estimating the actual capacity of the battery and therefore further optimises battery charging/discharging.
Smart Charging: Safer For You
The BMS also enables smart charging by communicating through the Type 1 or Type 2 connector to set charging limits using this information. Furthermore, it regulates the temperature of the batteries depending on the temperature of the environment (e.g. winter vs. summer driving). Apart from battery health, it captures the history of battery use to let operators know if the battery can be later used in an energy storage system for its second life.