As per the researchers, this principle should be applied when we're talking about any battery, not just LPF (lithium iron phosphate) writes Electrive. Scientists explain that this happens because at high charge states, the voltage of these batteries is high and if this is combined with fast charging over and over again, harmful compounds can be generated inside the batteries.

These deposits sit on the anode, which is responsible for the recharging of the batteries, so the useable capacity drops as the ions have less surface to make the transfer through.

"Cycling near the top of charge (75%–100% SOC) is detrimental to LFP/graphite cells. Our results show a correlation between the average SOC of battery operation and capacity fade rate, meaning that the lower the average SOC, the longer the lifetime", the authors explain. They added that, in order to prolong the battery lifespan, charging at high SOC (state-of-charge) should be avoided whenever possible.

This study contradicts what some manufacturers, including Tesla, recommend when charging an EV. Tesla says customers should charge LPF-equipped cars to 100% once per week, while Ford, once per month. The authors say that this is because these companies take into account multiple factoring when making these recommendations, including customer comfort.

So, the 20-80% rule, which has been praised by some experts regarding multiple types of batteries, should still be applied here for the longest-possible battery lifespan. It implies charging a battery and operating it between 20 and 80% most of the time.

It is, however, worth mentioning that currently-available batteries will degrade over time, no matter which charging habits you adopt, best you can do is slow down the process.