Ex Dynamics employ Ex design engineers experienced in IECEx and ATEX battery design using intrinsic safety ‘i’, increased safety ‘e’, flameproof enclosures ‘d’, and encapsulation ‘m’. Our hazardous areas experience allows us complete projects quickly and compliant to the appropriate standards. If you have a custom ATEX battery requirement, get in touch to discuss how Ex Dynamics can help.

We rely on batteries to power the devices we use in our everyday lives. But what are the considerations when designing ATEX batteries for use in Zone classified hazardous areas?

What are ATEX Batteries?

ATEX batteries are specially designed, tested and certified to meet the requirements of the ATEX Directive 2014/34/EU, which supersedes Directive 94/9/EC. These directives ensure the safety of equipment sold for use in potentially hazardous areas in the European Union (EU). Obtaining certification for use in hazardous areas outside the EU is possible using the IECEx scheme. The requirements in the UK have changed since leaving the EU and UKCA is replacing ATEX.

ATEX and IECEx battery design requires special techniques which prevent ignition during use in hazardous areas.

IECEx and ATEX battery design involves using an ATEX protection concept, to make it safe for use in the required Zone. Zone 0 applications usually use intrinsic safety or encapsulation, but Zone 1 and 2 applications can use less complex concepts.

ATEX Battery Applications

A variety of applications exist for batteries in hazardous areas. Common examples are personal devices such as gas detectors and phones, and backup for emergency lighting and Uninterruptable Power Supplies (UPS). Applications span all gas and dust Zones, so ATEX batteries must be designed and certified for use in appropriate equipment categories.

Primary vs. Secondary Batteries

It is possible to construct ATEX batteries using either Primary or Secondary cells. A Primary battery is not rechargeable, whereas a secondary battery is. Charging ATEX secondary batteries inside a hazardous area requires further considerations. Overcharging can cause excessive heat and venting so the charging circuitry must be robust, even with faults applied.

Suitable Chemistries and ATEX Battery Construction

There is no one battery chemistry most suitable for ATEX certification. It is possible to create ATEX batteries using common cell chemistries, for example Lithium-Ion (including LiPo, LiFePO4/LFP etc), Nickel-metal hydride (NiMH) and Lead Acid. The choice usually comes down to energy requirement, size and weight but temperature often plays a big factor.

Discharge curves for different ATEX battery cell chemistries

Temperature Considerations

Products used in hazardous areas commonly require an extended temperature range. Along with the potential performance challenges this can bring, it also makes certification more difficult.

During certification, the ATEX battery must be tested to ensure that under no operational conditions it is operated outside of its manufacturer’s specification. Therefore, designing high temperature ATEX batteries can be a challenging exercise. The same is true for low temperature ATEX batteries. For instance, it is not possible to charge most Lithium-Ion cells below 0°C, so we would source special cells for low temperature applications.

ATEX Battery Powered Electronics

A protection concept suitable for the equipment category must protect any electronic circuitry attached to the battery. This circuitry is also subject to certification. Discharging the battery too deeply can lead to reverse charging. Preventing this is just one of the requirements to achieve ATEX certification.

Read our article on battery technology for hazardous environments in HazardEx.