DC energy meter provides kWh-based charging experience for DC wall boxes

LEM offers its new DC energy meter for DC wall box EV chargers. Providing compliance with all the latest metrology regulations, the DCBM 100 energy meter will be released to the EU market in Q3 this year.

With the rapid ongoing growth of the e-mobility sector, the new DC energy meter is anticipated to be of particular interest to manufacturers of EV chargers to allow kWh-based billing when charging in public or semi-public areas. To provide for kWh-based billing of charging sessions, energy metering solutions must be integrated into destination DC chargers, following regulations such as the 2014/32/EU Measuring Instruments Directive (MID), German Eichrecht calibration law or French national regulation. kWh-based payment is increasingly demanded and enforced because it promotes accessibility, fairness, and transparency of prices for all users throughout the charging process of EVs.

EVs have the option of being charged employing either AC or DC power. DC charging through a wall box provides several advantages over AC charging because it overcomes the power limitation of the onboard charger utilised in AC charging. This produces shorter charging times and allows easier access to services like vehicle-to-grid.

With destination charging applications, where the charging time is typically one to two hours, an average charging power in DC in the range of 30kW is often adequate to recharge most EVs. To meet this demand, DC wall boxes are a crucial component of the charging infrastructure and provide reasonable charging times at an acceptable cost for charging point operators.

With its powerful bi-directional energy metering providing V2G, the DCBM 100 DC energy meter is created to provide full transparency and give end-users confidence in the fairness of their kWh-based charging experience. The future-ready meter has been designed specifically for 11kW to 30kW DC wall box applications, providing Class B accuracy and 1000V DC and 80A ratings in temperatures from -40C to +80C. Charging cables can be directly connected to the new meter.

Also, the meter delivers real-time additional data (voltage, current, power, temperature) crucial to designing predictive maintenance tools required to minimise EV charger downtime. As part of the company's larger family of direct current billing meters, the meter provides straightforward software integration and secure data handling using the latest Open Charge Metering Format.

Florent Balboni, LEM Global Product Manager for energy metering solutions, says: "Rapid deployment of new products and technologies is crucial to meet the diverse demands of EV charging applications. Ensuring fairness and transparency for all users, kWh-based billing is essential for technology acceptance. DC meters must therefore be tailored to EV charging applications such as DC wall boxes which will play a significant role in charging infrastructure and the development of advanced V2G services."