Railroad crossings are essential for train operation and road traffic safety. Rail companies install emergency power supply units at each crossing to ensure they operate properly at all times. This includes during scheduled maintenance work and temporary power outages.

Currently, these emergency power supply units use lead-acid batteries. However, efforts to replace these with repurposed Nissan LEAF batteries began in January 2021 at the Atago railroad crossing on the Jōban Line, which runs through Minamisoma City in Fukushima Prefecture.

A Nissan LEAF’s lithium-ion battery retains 60 to 80 percent of its electricity storage capacity at the end of its life cycle in a car. Therefore, by reusing used EV batteries, Nissan can use the battery’s remaining energy capacity elsewhere such as into new replacement vehicle batteries, or in this case, stationary batteries.

Nissan’s partner, 4R Energy Corporation, is responsible for this effort. Repurposing vehicle batteries can reduce the CO2 emissions and rare resource usage associated with building a new battery from scratch.

Meanwhile, for JR East, switching from lead-acid to repurposed EV lithium-ion batteries not only promotes sustainability, but also improved performance from the battery itself.

Compared to lead-acid batteries, the reused lithium-ion variety requires only 1/3 of the charging time. They are also far more durable, lasting on average 10 years, compared to 3-7 years for a standard battery. In addition, there is a control system attached, similar to an EV, enabling engineers to remotely check the battery’s status. This system also enables preventative maintenance by informing maintenance workers of the battery’s status before its voltage becomes too low.