26 fév 19

3 questions you should ask before choosing a wallbox

To add to the chicken and egg paradox: you bought an EV, now you’ll need to charge it. Here are three things you should know before buying a wallbox. 

Home chargers - mostly wallboxes - accelerate charging speed. If no garage is available, they can even be installed outside - they are weather proof. Nevertheless, there are tens of different companies providing wallbox solutions, including Wallbox, EVbox, Chargemaster, Pod Point and Rolec. All provide a high-quality product, but there are some features you should consider before buying the wallbox that suits your needs the best. 

1. How smart does it have to be?

Wallboxes come with a wide variety of connectivity and intelligence. You can have a basic one that charges on demand, or an intelligent one which can optimise charging and costs. Of course, the higher the degree of connectivity, the higher the price. We could divide wallboxes into three categories of intelligence. 

  1. Plug & Charge boxes are the most basic ones. As the name suggest, you plug in the car and the battery starts charging - that's it. Simply unplug to stop charging and follow the status via the LED lights. They usually don't come with an identification system, so reclaiming your costs afterwards is difficult. Newmotion and EVBox, who are leaders in public charging stations and offer their own charging card, do have basic wallboxes with a card reader. 
  2. Wallboxes with some smart charging services allow you the give the box permission to charge the car after activation with your personal card. Using the card allows the service provider to bill via the card, making it more convenient to claim the charging costs. 
  3. Smart wallboxes offer the same possibilities, however they are specifically designed for smart charging, therefore you can choose which service provider to use. Furthermore, the smart wallboxes are different in their way of communication. They might have a WiFi built in for updates or they could be connected to a smartphone or tablet application.

Smart wallboxes give you the opportunity to programme the charging process. For instance, charging during off-peak hours can save you a considerable amount of money. 

2. How much kW do I need?

Another crucial difference in wallboxes is the charging speed they offer. In general, there are two categories.

  1. 1-phase power outlet which provides a capacity from 2.4kW up to 7.4kW
  2. 3-phase power outlet which provides a capacity between 11kW up to 22kW. In case of the latter, the maximum charging capacity will be adapted to the charging capacity of the power outlet where you connect the wallbox to. For instance, if you connect the wallbox to a standard domestic power outlet, the maximum capacity of the wallbox will be 7.4kW.

To determine which one suits your needs, you should consider price and speed. Similar to the intelligence of the wallbox, the faster the charging, the more expensive the charger. For instance, if you would like to buy a wallbox from Pod Point in the UK, you can opt for a 3.6kW outlet at £779, or a 7kW outlet for £859, or for a 22kW charger for £1,499. 

Note that some in some countries, such as France and UK, there are subsidies to recuperate part of the purchase and/or installing cost of a home charging point. The Office of Low Emissions Vehicles Electric Vehicle Home Charging Scheme in the UK can cover up to 75% of the purchase price with a maximum of £500.

The higher the charging capacity, the higher the charging speed. For instance, charging a Nissan Leaf at a 3.6kW outlet will take you a bit more than 13 hours, while the 7kW outlet will do it in less than 6 hours.

Combining the two previous features, you can balance the price tag versus your actual charging needs. For instance, if you only use one battery a day, you don’t necessarily have to invest a couple of hundreds of euros more to charge faster. In this case a slow overnight charging would be sufficient.  

3. Which power input does my EV support?

So, you can choose a smart and fast wallbox, but before heading to the fastest one, make sure your EV can deal with the high-speed charger. Therefore, you should determine which maximum charging speed your EV can handle.

It is good to know that most EVs actually are limited to 7.4kW, in which case it makes no sense to invest in a 22-kW charger. The on-board charger inside the EV converts to received electricity from AC to DC and is the limiting factor. 

To give you an idea of the maximum charging capacity of some popular EV onboard chargers, we could divide them again in three categories. 

  1. The slow ones: EVs like the Peugeot iOn and Citroën C-Zero can take a maximum charge of 3.7kW
  2. The medium-fast ones, including the Nissan Leaf and the Hyundai Ioniq Electric (6.6kW), the VW e-Golf, Hyundai Kona EV and Kia e-Niro (7.2kW), and the Jaguar I-Pace and Mercedes EQC (7.4kW). 
  3. The fast ones, including the BMW i3, Audi e-tron and Tesla Model 3 (11kW), the Tesla Model S and X (17kW), and - interestingly - the Renault Zoé (22kW).

When deciding which wallbox to pick, you should take the previous three questions into account and balance your needs with the price, since the smarter or the faster, the more expensive the wallbox will be. And on top of determining how smart or how fast your charging process has to be, you should take into account the maximum power charge your EV can take. 

Authored by: Fien Van den steen