Staying ahead of the curve
Another key difference between AC and DC charging is the charging curve. With AC wallbox ev charger, the power flowing to an EV represents a flat line (so, not much of a curve at all). This is due to the relatively small onboard charger that can only receive a limited power spread over longer periods.
DC EV charger, on the other hand, forms a degrading charging curve. This is due to the EV's battery initially accepting a quicker flow of power but gradually asking for less as it reaches full capacity.
As an example, imagine a glass as the EV’s battery, a water bottle as a DC charging station, and the water inside that bottle as the power. At first, you can quickly fill the glass with water, but you’ll need to slow down as you get to the top, so the glass doesn’t overflow.
The same logic can be applied for DC fast and ultra-fast charging. This is why EVs require less power once the battery is around 80 per cent full, hence the degrading curve you see below.
Other factors that can affect charging speeds include:
AC for the grid and DC for the battery
Both AC and DC are important in the electric mobility world. You get AC power from the grid that is then converted to DC so it can be stored in an EV’s battery. When using an AC charging station, the conversion to DC happens inside the EV via an onboard charger, which is often limited. When using DC fast and ultra-fast charging stations, the conversion happens outside of the EV, using a larger converter.
Want to learn more about our AC and DC charging stations?
We provide a range of charging stations as part of our end-to-end electric vehicle charging solutions for businesses around the world. For a complete list of tech specs and use cases, as well as more information, take a look at our EV chargers for every business looking to electrify its operation.