1. Charging pile introduction
The appearance and performance of charging equipment vary widely. We often hear names such as portable piles, household piles, fast-charging piles, and public/operating piles. In addition, the interfaces of charging piles also include AC charging interfaces, DC charging interfaces, etc. For charging practitioners, they are also faced with a bunch of more confusing terms such as Level 1/2/3, Mode 1/2/3/4, etc. The summary is that there is so much jargon that it can be confusing. This article attempts to give you an easy-to-understand overview of the concept of charging.
Charging pile is the common name for Electric Vehicle Supply Equipment (EVSE). It is a tool for replenishing electric energy for electric vehicles, similar to the refueling equipment for fuel vehicles.
2. Characteristics of electric vehicle charging
The charging power of electric vehicles is not fixed. The characteristics of lithium batteries determine the charging curve, which changes. Simply put, it can be divided into constant current charging, constant voltage charging, and the final stage of float charging.
Therefore, the process of fully charging an electric vehicle is longer than the charging time obtained by simple division calculation (battery capacity kWh / charging pile power kW).
3. Common misunderstandings about electric vehicle charging
3.1 Want to shorten charging time and need to choose a charging pile with higher power?
The answer is not necessarily. If it is AC charging, the AC pile is just a power supply device, and the real charging power is determined by the on-board charger (of course, the power of the charging pile is lower than that of the on-board charger, so the bottleneck lies in the charging pile). The current mainstream on-board chargers are 3/7/11/22kW. If you use a 22kW AC pile to charge an electric vehicle with only a 3kW power OBC, the final charging power will still be 3kW.
3.2 Can I charge at full power using a DC charging pile?
The answer is not necessarily. Although there are no restrictions on the on-board charger OBC, and the DC pile charges the battery directly, the upper limit of the battery needs to be considered. The maximum power that the battery can support is also limited. The battery supports the highest charging power for most non-high-end electric vehicles and does not exceed 150kW. Even when charging at a 350kW super fast charging station, the charging power still cannot exceed the maximum power allowed by the battery (BMS). Of course, the charging power at different charging stages must also be considered.
4. Things to note when purchasing charging piles
At present, AC piles are the main household piles (the price and power of DC piles limit their installation in ordinary households). First confirm the power limit of charging piles allowed to be installed at home (confirm the home/community power distribution with the power supply company/property/electrician) Capacity), also confirm whether the home is a single-phase or three-phase household, and then confirm whether the electric vehicle on-board charger (OBC) purchased is single-phase (domestic electric vehicle OBCs are mostly single-phase) or three-phase, and finally buy the corresponding charger. Phase/three-phase charging pile. Theoretically, single-phase and three-phase charging piles and single- and three-phase on-board chargers are compatible. However, if the vehicle has a single-phase OBC, there is no need to install a three-phase charging pile.
