What does EV charger uptime actually mean?

When we speak with site managers and charger operators, everyone has horror stories of working with particular hardware and software providers. In most cases these point back to down chargers and slow recovery. However, at the same time, they often struggle to point to specific underlying reasons why particular chargers had issues.

As we move to a world where there is significant pressure on maintaining uptime, both from regulations and customer expectations, it’s critical to understand what actually causes chargers to go down.

Looking at the technology stack that is set up to provide a good charging experience, there is a set of sequential requirements that are required:

1. Site Power – is the charger receiving sufficient power
2. Network Connectivity – is the charger connected to the internet and is the software connection active?
3. Physical Hardware – is the physical hardware fully operational?
4. Charger-Vehicle Interface – can the charger communicate with the vehicle successfully and is the vehicle receiving what it is expecting on its side?
5. User-Network Interface – can the user correctly authenticate within the toolset of the network?

As a charger operator, it is important for people to be able to isolate these components to determine what is actually going on – especially given that it is often infeasible to go on site and visually inspect the chargers.

Let’s unpack these components in order.

Site Power

Site power is the first requirement for charging to happen. Unfortunately, troubleshooting power issues remotely is essentially impossible. However, sometimes fixing a charger power issue is as simple as flipping a breaker – you just don’t want to send someone to do this, only to find that it wasn’t the problem in the first place.

The key thing with power issues is that they need to be identified remotely. For many networks a “charger offline” looks the same whether it is networking or electrical. That should be a non-starter for site hosts – charging networks should be able to provide indicators that a charger isn’t receiving power separated from any networking error reporting.

Network Connectivity

Network connectivity is the single most common cause of charger issues, especially for level 2. Networking technology is a functional stack of its own – one which the charger operator should be able to granularly inspect to understand where issues are arising. A good network should provide a dashboard which indicates whether a charger is on WiFi or LTE, if the WiFi is connected, if internet is present on site, what LAN or carrier is the device connected on, etc.

The deeper a solution can get into network diagnostics the more reliable the charger will be and the easier it will be to recover in case of issues. For example, FractalEV provides a dashboard which shows a complete WiFi scan of the site including signal strength (RSSI) for each network and a cellular scan with all the available carriers at that given location. This kind of granularity provides the insight operators need to properly manage their assets.

Physical Hardware

Unfortunately, issues with physical hardware are difficult to detect programmatically and virtually impossible to fix remotely. For physical issues, beyond detailed electrical fault reporting providing clues, there is a necessity to visually inspect the hardware. For operators installing many ports, in practice this means using driver feedback as the main vessel of getting this information.

Creating easy channels for drivers to provide this feedback is critical to rectifying physical issues quickly. Today, many operators rely on either drivers being willing to spend time on a phone call in the moment or feedback from third party apps such as PlugShare or Chargehub. FractalEV provides a report issue button on the screen which provides a lightweight, on site option, to provide this feedback directly to the operator.

Charger-Vehicle Interface

The connection between the charger and the vehicle is increasingly becoming the source of issues for charging. One advantage of AC charging is that this generally has not been an issue, given that the vehicle does not communicate over the cable. However, it is certainly present with DC charging and will increasingly be a challenge with AC where Plug and Charge protocols are used.

In anycase, challenges here come from the complex handshake that must be performed between the vehicle and the charger in order to communicate. For example, some vehicles need a specific sequence of plugging in the vehicle, authorizing the charge session, and locking (or unlocking) the vehicle. The process of unlocking the charge connector from the vehicle is also not standardized – nor is it common knowledge of the existence of an emergency release for the charge cable, or where that release is located. 

All of this nuance leads to failed charge sessions that never show up on the balance sheet. While the charger may appear to be operational, the user still experiences a failure to charge.

User-Vehicle Interface

Lastly, the non-standardization of the user interfaces for the charge networks is challenging, and confusion on this point can lead to user frustration and low uptime scores. Each network can have a variety of different ways to start charges: QR Codes, RFID cards, or phone apps. Many of the popular charging hardware do not have screens, or have poorly lit, hard to read screens, or non-configurable screens. As a result, communication to the driver on how to charge can be challenging. Drivers can be confused when using a new station for the first time – leading to frustration and in some cases sessions where a driver opts not to use the charger. This is again an example of an “invisible” failed charge.

What does this mean for you?

As a site host, these components should be a guiding framework for charger procurement. In a sea of options for chargers, it is critical to at minimum look for:

1. A network that can distinguish and report between circuit outages, power outages, local network outages, and internet outages through their portal.
2. A network that can report detailed electrical fault codes and detectable issues that prevent charging. As a note, it’s worth confirming with your vendor that the system is auto-resettable: after a fault occurs, but is cleared, the charger should reset and continue functioning without user intervention (the users shouldn’t have to press the reset button)
3. A charger with a screen that is reconfigurable for the authorization method so drivers have clear instructions on how to interact with a station.
4. A plan on how users will report issues about chargers not working. Make it easy and simple for a user (in a non-urgent situation) to provide information about the health of your site.