Battery Charging Require Time

Battery Charging Require Time 

There are a lot of articles written about quick charging of batteries. However the word “quick” makes the reader think it is very fast while it in the reality means half or a full hour or even more if it is a big battery. Further, partially educated by the media, the general public reads that the future developments will bring the charging time to zero, which will not happen due to the law of nature. As an example to charge 90 000 Watt hours (90 kWh), one need high voltage and high currents. Suppose that you would try to charge three Teslas with 90 kWh batteries in the same time it takes to fill up a petrol car (3 minutes), then you need three phases, 400 Volts and 7300 Amps! Compare this to the 16 amps which are the common current delivered to residents. In a future large scale scenario where you may have 10 cars charging at a charge station one can see that the challenges are extreme.

Todays problems with EVs:

  • The larger batteries needed for a reasonable range, require additional time for charging, while the market need is for shorter charging times
  • The car is stuck during charging, it can not be used
  • A daytrip means you have to stop 1-3 hours to charge
  • A large scale fleet with EVs charged with ultra quick chargers means big size problem for the electric grid
  • Depending on the battery, the EV is still more expensive than a petrol or diesel car