what you need to know about ev battery health
while only one of multiple types of batteries, the past few years the popularity of lithium-ion (li-ion in short) batteries has steadily grown: their combination of performance, flexibility and decreasing costs makes them not only particularly suited for use in consumer electronics like smartphones and portable devices, but electric vehicles (evs) as well. here's what you need to know about ev battery health.
It is easy to understand why electric car manufacturers choose to power their vehicles with Li-ion batteries. Because their energy density is much higher than, for example, lead-acid or nickel-cadmium rechargeable batteries, they can reduce the overall size of the battery pack and easily fit in in a normal-sized car. However, there are other factors to consider as well: in the automotive industry, safety is paramount.
Factors affecting battery degradation
Lithium-ion battery is a low maintenance system: it does not require scheduled cycling to prolong its life, nor does it have the sulfation problem of lead acid batteries, which sometimes occurs when those are stored without periodic topping charge. And in case problems should occur, EVs are equipped with charging safeguards, ensuring the batteries are sufficiently protected during repeated charging sessions in a short period of time.
Still, repeatedly charging a battery is always going to cause degradation. High temperatures, operating at high and low state of charge and high electric current as well. As a result, the amount of energy the battery can store is reduced, as is the amount of power it can deliver. But because a Li-ion battery used in an EV is generally able to deliver more power than the car needs at any time, only the decreasing energy storage is of importance. It is also key to note that a decrease in storage capacity is not necessarily proportional to an EV's action radius: factors like temperature, driving habits and cargo/passenger load also come into play here.
Not all Li-ion batteries are the same
Though generally designed to maintain optimal efficiency over at least 1000 full-charge cycles, most EV batteries last even longer. EV manufacturers offer warranties, which usually cover a certain amount of time and a certain number of kilometres driven, and end when a threshold is met. These differ between manufacturers, and consumers are generally advised to study these closely.
Also, please note that not all batteries are the same. While research has shown that EV batteries generally decline non-linearly (an initial drop, followed by a more moderate decline and a significant drop at the end), depending on their make and model they respond differently to the test of time. The jury is still out on this one, but battery chemistry and thermal management are potential contributors to faster degradation.
Understand batteries better
In any case, having a monitoring and diagnostics solution with real-time statistics on battery health and performance helps prevent potential issues and to plan maintenance.