Advice from the chemist: If you charge like this, you will kill your battery
E-cars usually contain Lithium-ion batteriesBut there are different types, and not everyone knows the exact type that is installed in their car. But knowing it is important, because you have to Load take this into account, otherwise the battery will prematurely breathe the end of its electrical life.
A current tip could help extend the life of batteries like those in Tesla’s Model3 and Y or BYD Seal! Because their single-axle driven models as well as entry-level vehicles or compact electric cars contain an LFP battery. This is also the case in the Volvo EX30, MG4 and MG5, or also in Citroën ë-C3.
Such LFP batteries should not be fully charged too often, especially not when they are still almost full. This is the result of a new Study by the Electrochemical Societya US research institute in Pennington, New Jersey. This kills the battery faster than if you regularly charge it down to the recommended minimum charge of 20 percent. (So an electric car battery lasts longer).
Here is the technical background: LFP batteries were constructed on the basis of lithium iron phosphate (this is what the Battery of the future). They have the advantage of costing less than conventional Li-ion batteries because they largely do not contain nickel and cobalt. In return, their power density is lower. They are also more sensitive to cold.
Why Tesla recommends full charging
Problem now with the LFP battery: Manufacturers like Tesla recommend that cars with this battery be regularly fully charged to 100 percent so that the battery can be calibrated. This is necessary so that the car can estimate the remaining range more accurately. According to the current US study, constant full charging to full charge should be avoided.
It is particularly bad if you pump an almost fully charged lithium iron phosphate battery back up to 100 percent. Why? Because the higher voltages and the heat generated produce harmful substances in the battery. In turn, the lifespan of the energy source is shortened.
Researchers at the Electrochemical Society measured the charging curves of LFP batteries in different charging states. The result: Full charging too often damages the battery.
Image: Journal of the Electrochemical Society
How frequent charging shortens battery life
What happens exactly: Harmful crystal compounds, also known as dendrites, accumulate on the negative pole of the battery. They reduce the battery’s performance over time. It is particularly harmful not to drive a fully charged car with an LFP battery straight away, but to leave it fully charged first.
The researchers tracked down the effect by measuring the current flowing and its voltage in all charging states, i.e. from 0 to 25 percent, 0 to 100 percent and from 75 to 100 percent. The energy output, the effectiveness and the number of charging cycles were also taken into account.
What effect does this have on the lifespan of the battery? That is difficult to quantify. According to Tesla, the lifespan of LFP batteries is up to 10,000 charging cycles. With an average charge of 200 km, this would theoretically correspond to a driving distance of two million kilometers.
The new study reinforces the knowledge that a fully charged electric car should only be recharged when the battery level is low, which is interesting. Leaving a fully charged car standing is also not advisable. This knowledge is probably not yet very widespread.
