Bringing more energy to the battlefield: Saft batteries power Etic Telecom’s autonomous tactical Ethernet switch repeater

Etic Telecom chose Saft’s rechargeable lithium-ion MP 176065 xtd batteries to equip their XSMIL-FD4200, a Tactical SHDSL Switch-Repeater deployed in harsh environments. 

Etic Telecom’s challenge: Designing an efficient, simple, sturdy, and autonomous power solution, adapted for use in demanding environments

The success of a military operation depends greatly on the ability of a combat force to communicate their intentions and operational orders, quickly, clearly, and above all securely. A robustly networked force enhances information sharing and collaboration which in turn, increases the mission’s effectiveness.

For highly critical strategic and tactically-oriented military operations, communications must be 100% reliable and secure. Which sometimes means switching from undulatory to silent radio mode. In effect, going wired.

Ethernet is one of the most robust technologies available and an ideal choice to handle data transmission safely and smoothly as cables do not emanate radiation, and communications can be encrypted. Whilst it doesn’t replace wireless ground-to-air, nor ground-to-satellite connections, Ethernet perfectly completes the key security infrastructure by providing a secured ground-to-ground communication network whenever no broadband is needed, possible even while on the move. This is the main reason why industrial Ethernet equipment has been deployed in various military and defense operations worldwide.

Etic Telecom is a French company that was created in 1985 and which is part of the French Fab, the French industry ecosystem label. Their specialty: designing, developing, manufacturing, and marketing communication products for B2B professional markets. Their networking technologies allow companies to enhance communication and interconnections between industrial equipment —Machine to machine, Machines to operator etc... Originally, this was achieved by using telephone networks, now it is based on cellular and Ethernet technologies.

Using cables might seem unusual when it comes to IoT, often considered as a wireless technology. However, optimizing the already existing infrastructures saves money as there is no need to deploy any additional network. It is also a smart and sustainable way to repurpose the use of cables, especially when your communications do not require broadband.

Etic Telecom developed an Ethernet infrastructure for military vehicles. The XSMIL-BP4200IB SHDSL tactical switch equips army vehicles, creating a network of connected cables that enable communication between separate armed forces. But Ethernet cables cannot be deployed as such over long distances because then the signal weakens and becomes unsteady. Etic Telecom and the army needed here an Ethernet extender based on SHDSL technology to carry messages over several kilometers to meet new issues arising in the field.  

Enter the XSMIL-FD SHDSL Tactical Repeater & Switch. The XSMIL-FD extends Ethernet connectivity using SHDSL modulation. It receives a signal and re-transmits it, usually with higher power and from a better location.  Buried in the sand, the repeater —which is the size of a small suitcase— can therefore provide a greater communications range between vehicles.

Several repeaters can be daisy-chained together to increase the communication distance between vehicles thereby increasing the potential range.

At first glance, this seems simple enough, but in its rigorous drive for security, conceptual simplicity and sturdiness, Etic Telecom had to find the right battery to power that smart solution.

Indeed, such a sensitive portable device needs to be 100% reliable, even —or shall we say especially!— in the harshest terrestrial military environments:

• It needs to be powered and autonomous
• It needs to resist dust and/or humidity
• It needs to resist rough handling in the operation grounds
• The rechargeable battery must sustain high or very low charging and discharging temperatures, (which, if you’ve read our article on the subject you’ll know can be a hurdle)
• It needs to offer various methods and means of charging —at the station with a charger, in the car using a cigarette lighter, or via an external local power supply in operation (solar panels, battery, etc)
• The power source needs to be electromagnetically compatible since the device is based on an active electronic infrastructure that radiates.
• The battery needs to be small whilst delivering a high amount of energy (80 Wh)
• The battery needs to be intrinsically protected and accessible to be dismantled and replaced easily.
• The client requires 24hrs autonomy for the solution and an MTBF (MeanTime Between Failures) of 40,000 hours in the field.

Moreover, as the switch repeater is part of a much larger military ecosystem, Etic Telecom had to keep up with the pace of development of the other devices in the range to avoid being singled out as the weakest link.

The solution: a Saft MP 176065 xtd - Li-ion rechargeable battery pack

With Saft, Etic Telecom found the perfect partner to help them deliver on time a customized battery pack meeting all their technical requirements.

Firstly, Saft is based in France, an important fact for Etic Telecom. Proximity made it simpler to manage the time challenge and to organize the shipment of the products and prototypes; and speaking the same language helped facilitate communications between Saft’s and Etic Telecom’s teams.

Secondly, Saft has an unrivalled experience of manufacturing Li-ion cells for demanding sectors such as space and defense or datacenters. We have a wide array of products capable of powering nearly any application under any circumstances. And beyond the manufacturing of the cells, our teams offer training and advice and create bespoke technical solutions considering your application’s constraints.

The choice was made, and the collaboration started!

The initial challenge ­—the fact that the battery should be able to work in a severe environment and be charged and discharged under extreme temperatures (-30 + 85° in charge / -40° +85° in discharge)— was met by Saft’s MP 176065 xtd, a Li-ion rechargeable cell that offers an operating temperature range between -40°C to +85°C.

The MP 176065 xtd delivers a high energy density in a compact format. It loses very little capacity under storage and can be activated right off the bat, even if it has not been used for a long time. The cells are hermetically sealed and intrinsically protected. They can operate in any orientation, they are maintenance free, and they are designed to meet all major quality, safety and environmental standards. The battery pack also successfully passed the stringent UN38.3 tests proving it is safe for transport.With that, Etic Telecom had almost all the basics covered.

From there, they worked with Saft’s battery development team to design a customized battery system and fine tune the solution.

The electromagnetic constraint was another challenge to address. The battery must not disturb nor be disturbed by the surrounding waves. The battery casing was then designed as a Faraday cage to perfectly insulate the battery. The system here is fully electromagnetic compatible (EMC) making it safe to operate in electromagnetic environments.  The battery enclosure also meets the IP67 standard meaning is it hermetically proof to dust and water.

A built-in charger system allows the battery to be fully recharged in 6 to 8 hours using a local power supply. Thanks to a smart Battery Management System (BMS) the battery communicates with a state-of-charge indicator and flashing diodes located in the case.

Etic Telecom’s MTBF targets are high level: 40,000 hours in the field and 500,000 hours (20,000 days) in an indoor/standard environment without failure!  All in all, an extremely dependable product that will enable troops to effectively manage their communications whilst not failing them in the combat arena.

Altogether, the development took almost 2 years to finalize.

With Saft MP 176065 xtd and Saft’s development teams, Etic Telecom met their use case, delivering an efficient, simple, sturdy and durable solution, adapted to the use in the desert and offering at least 24hrs of autonomy in the field.

Key benefits for Etic Telecom

• A battery made in France, offering complete reliability for a sensitive application
• A battery that can be charged and discharged under extreme temperatures (-30 + 85° in charge / -40° +85° in discharge) using several charging options to allow for complete flexibility in the field
• A rugged solution, featuring an intrinsic high sealing and shielding level, protecting the cell from desert conditions such as shocks, dust, or humidity and allowing for easy dismantling and replacement of the battery
• An electromagnetically compatible solution that prevents any radiation within the active electronic infrastructure of the Switch-Repeater
• A compact solution capable of delivering the necessary 80Wh of energy required to power the Switch-Repeater.
• A joint development between Etic Telecom and Saft, delivered in time and in full confidence, despite a challenging pandemic context.  

Features of Saft’s power solution

• A rechargeable battery offering an unrivalled operating temperature range from -40°C to +85°C, adapted to outdoor operations
• An aluminum, hermetically sealed casing offering a high level of integrated safety
• A battery featuring a high energy density (264 Wh/l; 150 Wh/kg) and a high nominal energy (20.4 Wh) while remaining compact
• A comprehensive, bespoke offer and technical solution considering the client and the end user’s demanding specifications

For more information on Saft lithium-ion rechargeable batteries, visit the product page: https://www.saftbatteries.com/products-solutions/products/mp-small-vl

How to best charge your lithium-ion batteries to expand their lifetime, find out here: https://www.saftbatteries.com/energizing-iot/charging-your-lithium-ion-batteries-5-expert-tips-longer-lifespan

How to take good care of your lithium-ion batteries while in use, find out here: Lithium-ion batteries in use: 5 more tips for a longer lifespan | Saft Batteries | We energize the world.