East Japan Railway Company (JR East) is trialing repurposed Nissan LEAF EV batteries to power its railroad crossing devices.
Railroad crossings are essential for train operation and road traffic safety and hence rail companies the world over 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. Replacing them with repurposed EV batteries could pave the way for a more sustainable society, notes Nissan.
JR East has been using repurposed Nissan LEAF batteries at the Atago railroad crossing on the Jōban Line, which runs through Minamisoma City in Fukushima Prefecture, since January 2021.
According to Nissan, its LEAF’s li-ion battery retains 60 to 80% of its electricity storage capacity at the end of its life cycle in a car.
By reusing used EV batteries, the automaker contends that it can direct that remaining energy capacity elsewhere, such as into new replacement vehicle batteries or stationary batteries. Nissan’s partner, 4R Energy Corporation, is responsible for this effort.
According to JR East R&D center’s assistant chief researcher Kaito Tochihara, 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.
But the biggest difference happens to be battery maintenance, notes Tochihara:
“With lead-acid batteries, we have to periodically visit railroad crossings to check the state of charge and any deterioration.”
“However, with repurposed lithium-ion batteries, there is a control system attached, similar to an EV, so we can remotely check the battery’s status.”
“This should lead to improved maintenance standards. This system also enables preventative maintenance by informing us of the battery’s status before its voltage becomes too low.”
Another plus, the repurposed Nissan LEAF batteries have been designed to withstand lightning surges.
Generally speaking, if lightning strikes an EV, the electricity flows to the ground through the vehicle’s body. This prevents the sudden abnormally high voltage (the lightning surge) from flowing into the battery.
However, at a railroad crossing, the battery is connected by cables to devices such as barriers, alarms, and control equipment. If lightning strikes nearby, then the voltage can flow directly into the battery through those cables.
To enable the batteries to withstand such surges, modifications were applied to the battery’s control infrastructure from the development stage.
In addition to the Atago railroad crossing, JR East also plans to test the batteries at other railroad crossings on the Jōban and Mito lines.
Image and content: Nissan
