There is also such a thing as damaging your battery by looking too much after it

Of course, the well-known two rules of thumb apply:

  • Slow charging is better than fast loading
  • Using the battery between 20-80% is preferable


But these two rules are not as correct as one might think. Because they refer exclusively to the battery cells themselves. But the HV battery of an electric car is made up of more than just individual cells.


Battery cells like to be used between 20-80%. In itself, that's true. But a good example here is the smart electric drive from 2012 to 2015. But if you don't use its battery normally and never let it reach 100%, you're doing more damage to it than you help it lasting longer.

Only at 100% SoC it begins to balance the individual cells again. It has happened several times that in this case the supposed protection of the battery by the owner caused more damage than helped.


The issue surrounding slow loading is similar. Of course, it's better for the cells if you charge them as slowly as possible. But in return you have to accept a multiple increase in the stress on other components.

The cooling pumps then run many times more hours and wear out more. All the electronics also accumulate more hours and that also costs lifetime in the long run.


It is just not a good idea to transfer recommendations from Tesla, for example, for their batteries to other cars. Tesla gives recommendations for their batteries and these are also good for their batteries. I also give recommendations for smart batteries, for example, because I am familiar with them. But only because the smart mentioned above is like it is, doesn't men that it's the same for other cars.

Ultimately, however, every manufacturer has slightly different cells, different firmware on their BMS (battery management system) and other general circumstances such as cooling and the layout of the HV battery.


Accordingly, you should only stick to the manufacturer's recommendations and make sure that you follow them for your own model.

Likewise, it makes no sense to blindly follow practices based on cell phone and laptop batteries. These are only intended for the cells and ignore the rest of the vehicle.


And at the very end the most important recommendation is:

Simply use the battery as you need it. Charge it whenever you want and drive it as full and empty as necessary. It's not for nothing that manufacturers give an 8-year guarantee on their batteries. The batteries can handle it without any problem.

The BMS is there to protect the battery and it can do its job best if you don't feel like you have to help it. If you do something that is not good for the battery, it will take care of itself and slow you down. After all, the manufacturer doesn't want to have to replace the battery under warranty.


This post was originally written for my personal Twitter and Linkedin accounts. I then published it here so it won't get lost in the depths of social media. I would also like to be able to see how my statements have aged in 10 years time.

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