How Long is the Lifespan of EV Battery
The lifespan of a power battery is closely related to the method of use. The same battery can last 10 years for some users, while others may find it fails after 8 years. In daily use, it is important to protect the battery to extend its lifespan.
The lifespan of a power battery is closely related to the method of use. The same battery can last 10 years for some users, while others may find it fails after 8 years. In daily use, it is important to protect the battery to extend its lifespan.
Power batteries are different from fuel engines; they are quite sensitive and require an optimal temperature to operate effectively. Whether charging or discharging, power batteries generate heat, which must be dissipated promptly at high temperatures to avoid damaging the battery’s lifespan. Overcharging or over-discharging can also harm the battery.
For instance, high temperatures can affect battery life, but car manufacturers have taken this into account. When the battery temperature is too high, the Battery Management System (BMS) signals the vehicle to activate its cooling system to cool down the battery pack. Similarly, when the battery temperature is too low, the vehicle will activate the PTC heater to warm the battery.
Temperature control is automatic, set by the manufacturers, and requires no consumer intervention. You just need to drive normally, regardless of whether the temperature is high or low.
How to Charge Your EV Correctly
EV driver can take two main actions: first, try not to discharge the battery too deeply; second, avoid fast charging at low temperatures.
Try not to let the battery’s charge drop below 20%. In other words, start charging when you have 20% remaining. This can indeed extend the battery’s lifespan. An important parameter in the battery cell is the Depth of Discharge (DOD), which is the percentage of the battery’s discharged power relative to its current available capacity. DOD is calculated as 100% minus the State of Charge (SOC), which represents the remaining charge. A simple way to understand DOD is to consider how much power has been used. For example, if you have 20% remaining charge, then the DOD is 80%. The lower the remaining charge, the higher the DOD.
To conclude: the higher the DOD, the faster the battery ages, meaning the less remaining charge each time, the less durable the battery. As shown in the diagram, a DOD of 10% results in the highest cycle life for the battery, while a DOD of 80-90% results in the lowest.
The greater the DOD, the fewer the number of cycles of the battery, the lower the life
The greater the DOD, the more the battery capacity is lost, and likewise, the lower the battery life.
Although some lithium ions may be lost, they do not disappear. They remain near the battery’s negative electrode but transform from lithium ions into metallic lithium, appearing as a silvery-white substance on the surface of the negative electrode. This phenomenon is known as “lithium plating.”
The Best Charging Way for Electric Cars
If charging continues at low temperatures or with high currents, lithium metal will begin to crystallize, growing slowly like branches and accumulating many branch-like shapes, known as lithium dendrites. If the dendrites grow large enough, they can pierce the battery separator, causing a short circuit between the positive and negative electrodes, which can lead to a fire.
During low-temperature charging, the vehicle’s PTC heater is initially activated using power from the charging station to heat up. Only after the battery’s temperature rises does it begin to charge slowly. In cold environments, the battery’s insulation efficiency is low, and most of the heat dissipates into the air, meaning the battery’s temperature during low-temperature charging will not reach the levels it does in summer. Therefore, fast charging in low temperatures is definitely harmful to the battery.
Fast charging always damages the battery, and fast charging in low temperatures causes even more harm. This doesn’t mean fast charging should never be used, but it’s best avoided if possible. Occasional use when in a hurry is fine, as the damage mentioned above accumulates over time and is not the result of one or two charges.
For friends in the north, during winter, try to park your car in an underground garage to keep the battery warm and avoid large temperature differences.
Conclusion
In summary, during daily use, charge the battery when it drops to 20% if possible, and prefer slow charging. In winter, try to avoid fast charging. By adhering to these practices, a battery can last 10 years without issue.
