Why Traffic Group Signals turned to S Jones for safer battery charging

S Jones Containers develops safe battery charging solution for Traffic Group Signals

Container conversion specialist S Jones Containers has completed a custom-built battery charging facility for Traffic Group Signals.

The project was designed to provide a secure and compliant space to charge lead acid batteries at the manufacturer’s new site.

Traffic Group Signals required a solution for charging Valve-Regulated Lead-Acid (VRLA) batteries that power its traffic light systems.

Because hydrogen gas can be released during the charging process, the risk of fire or explosion made it impossible to insure a facility within the new building.

S Jones Conversions was therefore commissioned to design a standalone, containerised solution that could be installed away from the main premises and allow emergency service access if needed.

Design engineers develop tailored two-compartment system

The conversion team at S Jones worked closely with Traffic Group Signals to create a system that met all operational and safety requirements.

The design used a 20ft high cube side-opening ISO shipping container, adapted by S Jones engineers at its dedicated workshop.

A fire alarm system was integrated with a relay link to a contactor safety circuit, cutting power to the charging compartment automatically in the event of an alarm or manual e-stop activation.

The company’s patented Contain-a-Lock system was installed to add security.

The unit was divided into two sections using a fire-rated, gas-sealed bulkhead.

The smaller section houses standard charging equipment, while the larger compartment contains bespoke racking to hold up to 48 12v VRLA batteries.

Each rack position includes dummy DC charging connectors to keep cables clear when loaded by forklift truck.

Ventilation and safety systems meet British Standard requirements

All construction and installation followed BS EN IEC 62485-2:2018, the Safety Requirements for Secondary Batteries and Battery Installation.

S Jones engineers calculated the highest possible hydrogen emission rate based on full simultaneous charging of all 48 batteries.

Based on this modelling, the team installed a ventilation system incorporating ATEX Zone 1 lighting and an ATEX Zone 1 fan-forced air design.

A secondary safety fan was added to ensure hydrogen levels would remain below explosion limits even in the event of a fan failure.

The ATEX ventilation circuit operates automatically whenever any of the 48 chargers is switched on.

Collaboration ensures technical compliance and project delivery

Andrew Nicholls, Head of Conversions at S Jones Containers, said: “As with every project we undertake, every detail here was carefully considered by our in-house design engineers to make sure the unit perfectly met the criteria from a safety and usability perspective.

“It also allowed the customer’s fire alarm to connect fully to its existing battery management system for remote monitoring.

“The positioning of the DC cables was such that in the event of forklift truck damage to an individual cable, it could be quickly replaced to minimise plant downtime.

“We pride ourselves on providing a solution that goes beyond meeting regulations and which ticks all the boxes for our customers.”

Mark Hutchinson, Director at The Traffic Group, commented: “The design and construction of a bespoke battery charging facility was new ground for Traffic Group Signals.

“S Jones provided us with advice on the design and technical aspects of our proposed unit, having listened to our original requirements.

“They guided us through the options available to us, to arrive at a design that not only fulfilled our needs but complied to all the relevant safety standards.

“They involved us throughout the process and completed the unit to the agreed schedule.”

Relevance for fire and safety professionals

Battery charging environments are high-risk areas where hydrogen gas emissions can lead to fire or explosion if not managed correctly.

This case shows how containerised systems designed to BS EN IEC 62485-2:2018 can provide compliant, isolated charging facilities for industrial and manufacturing sites.

The project highlights the practical use of ATEX-rated equipment, fire-rated bulkheads and automated ventilation circuits in reducing ignition hazards.

Fire safety engineers, risk assessors and facility managers working with battery storage and charging systems can take reference from this installation’s design, which integrates active fire detection, automatic shutdown, and gas-safe ventilation control.

The approach may inform future planning and insurance compliance for facilities using lead acid or other energy storage technologies.