Improve EV charging reliability with charger success rates: How CPOs can optimize EV charger performance

The public charging market is growing, yet concerns around EV charging reliability remain a barrier to the e-mobility transition. Much of these concerns are unfounded – Kempower EV chargers offer an average uptime of over 99%, but areas for improvement remain. 

Aiming to change perceptions of public EV charging being unreliable, Kempower has measured charging success rates across its chargers for five years using the data on ChargEye, Kempower’s EV charging management software, to identify these areas. Results from over 13 million charging sessions inform data-driven improvements to Kempower’s charging hardware and software and the advice we give to partners and customers. 

This blog will dive into Kempower’s charging success rate data to show how data-driven improvements can help optimize EV charging reliability. It also provides a guide for CPOs on how to optimize the charging experience to improve charger reliability and attract more customers to their EV charging site. 

Note: To understand what each type of charger success rate means, read the first blog post in our charging success rates in public charging series. 

How to prioritize user-friendliness in EV charging design

As our previous blog concludes, errors caused by EV drivers make up 81% of charger failures, making improving the user-friendliness of the charging process a priority. ~75.7% of user failings are due to failed authentication and ~13.8% due to improperly connected charger cables. Clearly, reducing error through user negligence by making the charging process easier to understand is key to improving usability rates.  

• What Kempower does: We made steps to improve the usability of EV charging apps and optimize Kempower chargers’ user interface to be as intuitive as possible, for example by reminding the end-user to check that the charging session had started before leaving the charging site. 

• What CPOs can do: Since so many EV charger failures arise from end-user error, it’s important that customers clearly signpost how to use the charging point properly. This means using a charging app provider that centers user-experience. 

How to reduce technical failings at EV charging points 

Most of the technical problems we have identified at EV charging sites call for actions from charger manufacturers, CPOs and EV drivers themselves. When investigating the reasons for technical failures, we found that the two most common failures were locking issues (~44.1% of all technical failures) and EV communication issues (~47.1% of all technical failures). Solving these problems requires a collaborative approach. 

• What Kempower does: After first analyzing these results, we experimented with plugs from multiple different manufacturers before choosing our primary supplier based on the plug locking design. When it came to addressing EV communication issues, we used Kempower’s EV identification technology to identify the EV models at fault while adjusting Kempower software to tolerate non-standard behavior if it is not a safety related feature. OEMs have twice launched a callback campaign of EV batches based on our information.  

• What CPOs can do: Locking issues can originate from various sources such as a faulty EV connector, a worn-out plug, or improper connection by the user. To solve this issue, we advise our customers to make their charging fleet as user-friendly as possible by guiding operators to favor drive-through chargers over traditional parking. We also recommend guiding EV drivers to support the plug while connecting to prevent locking issues through user error. When we trialed this by adding instructions to EV charging apps and attaching explanatory stickers to Kempower charging dispensers, the relative number of locking issues decreased by approximately 10%. 

How to guarantee EV charging availability

Charging availability is essential to the success of all other rates. For a session to even be possible, the charger has to be available for charging.  

• What Kempower does: All Kempower DC fast chargers employ dynamic charging, which reduces charging and waiting times by distributing power based on need. The result is a 99% charging availability for Kempower chargers.  

• What CPOS can do: Our customers can work with the Kempower team to ensure availability at charging sites. Kempower helps customers calculate the optimal number of plugs and levels of power for their specific customer charging scenarios.  

Making reliable EV charging the norm 

Kempower’s exhaustive data gathering and analysis of various success metrics reveal the need for actionable solutions to common charging errors, with a particular focus on improving usability and educating EV drivers. Joint efforts between charging manufacturers and CPO customers is key to ensuring EV charging reliability, which is why Kempower collaborates with customers throughout the process of installing a charging site. 

Want to offer reliable charging infrastructure at your charging site? Kempower can help you achieve data-driven results. Get in touch today. 

Read more about our findings about charging success rates in public charging in our new white paper. 

Written by

Mikko Veikkolainen

Vice President of Research and Innovation, Kempower