Charging forward

When meticulous detail can mean the difference between life and death, asking a seemingly uncomplicated question can often elicit the most complex of answers. Take this one: ‘how much weight does a soldier carry?’ The answer? Well, that can depend on innumerable factors, but some studies from recent conflicts have shown dismounted ground combat troops carrying anywhere between 90–140lbs into combat – in other words, quite a lot.

That weight – referred to by terms including ‘combat load’ and ‘buttload’ – has only grown for the dismounted soldier in recent years. The concept of dismounted soldiers has been around throughout history; but the roles they play and tools they use have changed dramatically. From planning and strategizing, to fighting on the frontline, technology’s influence is increasingly palpable, resulting in the fastest and most far-reaching overhaul of the soldier’s toolkit in history.

Today, soldiers have access to operational awareness and communication capabilities like nothing we’ve seen before, supported by a vast and growing catalogue of tech. These include – but are by no means limited to – rugged military tablets and communications systems, GPS-enabled devices, and body-worn cameras and sensors, as well as nightvision goggles and thermal cameras. Each of these are carried in addition to first aid kits, water and food, ammunition, armour and more.

Packing the power

Although technologies offer significant mission benefits, they come at a price – an increased load, which includes the devices and means to power them. “Not just for the dismounted soldier, but pretty much across the whole of defence, there’s been a significant increase in power and energy demand, obviously, as we start fielding more capability,” explains Darren Browning, senior technical lead for power sources at the UK Ministry of Defence’s (MoD) Defence Science and Technology Laboratory (Dstl).

Although it’s hard to put a figure on it – as it’s dependent on the dismounted role and unique requirements of missions – broadly speaking, section commanders are believed to be consuming an average of 8W over an eight-hour mission, and riflemen about half that; assuming each is using standard equipment.

It is, however, the rifleman role where Browning says the increase in power demand will be greatest. “A commander has always had a fairly capable radio with a fairly high power draw […] So, broadly, there shouldn’t be a huge increase,” he says. “But the rifleman essentially had very little capability back in the day, and now they are going to have more capable equipment and more impressive data radios. That’s probably where you see demand will increase most.”

It’s fast becoming the main subject of interest among some of the world’s most capable fighting forces, as, according to Browning, they ask: “As our reliance on power hungry technology increases, how can we decrease the power sources needed to supply them?” It’s a conundrum ever-more entwined with a shift in combat dynamics, as the world moves from counterterrorism and counter-insurgency to something more akin to a bygone age of war – as events in Europe and, more recently the Middle East, have shown.

During the siege of Mariupol between 24 February to the 20 May 2022, Ukrainian forces were beyond the scope of supply chains for an extended period of time. Held down by the Russians, they had to ration supplies, including power – demonstrating a very modern problem, which is as we depend on technology more, the ability to operate effectively is greatly hindered when it’s no longer available. Browning says the logistics of power supply is one of the least understood elements of the supply chain, while also being the most rapidly changing as technology evolves and capabilities increase.

Key to addressing this challenge will, Browning believes, be standardisation. “There’s always a logistics challenge to any military operation, and that’s not going to go away. But we can reduce and make that simpler by having fewer types of batteries in circulation,” he says, adding that it’s an area the UK, US, Nato and others are currently looking into.

However, Browning continues, the problem can’t be resolved with a single ‘magic’ technology. “Essentially, you need to move energy forward, but you need to do that in the most efficient way possible while trying to reduce your electrical load – [and] that’s going up because we’re adding more capability,” he notes.

One for all

For well over a decade, the US military has been hard at work tackling this issue. Their achievements so far have led to ambitious hopes for greater interoperability – doing away with the need to carry a host of device-specific batteries. After the push to modernise announced under the stewardship of then-US Army Chief of Staff Mark Milley in 2017, the Army embarked on the research and successful development of the Small Tactical Universal Battery (STUB).

Among the challenges the US Army’s Command, Control, Communications, Computers, Intelligence, Surveillance and Reconnaissance (C5ISR) Center’s Tactical Power Team identified include the varying voltages devices operate at, ranging from 3.3V to 21V; form factor, determined by the energy a device requires which in turn dictates the size and weight of the battery; the differing mechanical and electrical connections; and the enhanced environmental resilience and operational burden needed.

The STUB, a lithium-ion family of batteries comprising eight different sizes, was designed for devices from radios and GPS systems to sensors and ranging and targeting, among others. Thanks to a standardised mechanical and electrical interface – and an ability for soldiers to select the power supply – the ‘one device, one battery’ issue was finally addressed.

The programme was followed by a project seeking to develop AA form-factor military-grade batteries capable of recharging, bridging the growing void between legacy systems’ requirements and the higher instantaneous power draw of next-generation devices using the AA form. These Operational Single Cell for Accessory Readiness batteries will be capable of recharging more than 100 cycles, with prototypes ready for field testing in coming months.

“I guess where we are is still in this transition from lots of decentralised power sources to a centralised battery; and also transitioning from single-use batteries to more recharge-use batteries,” says Browning, “A sort of mixed blended space at the moment.” Asked about US standardisation, he says, “We’ve yet to take a view as to whether [STUBs are] the right answer for us. But it may well be the right approach, because we don’t wish to reinvent the wheel and have a unique battery for ourselves, unless there’s a reason to.”

However, that’s not to say the UK isn’t carrying out research of its own. The Generic Soldier Architecture (GSA) concept, introduced in 2021, has helped shape the future development of technologies for soldiers, while trying to ensure they are as standardised and open-system as possible; underpinned by the principles that systems should be modular, scalable and free from restriction of use.

As a result, the plug and socket – the interface – used on the batteries being deployed is now largely consistent, increasing interoperability across UK armed forces and other militaries, with the US and other Nato members opting for the same approach. “[While] not adopted by everybody, yet,” explains Browning, “we now have a standard power interface for dismounted soldier equipment, which will be suitable for a large range of equipment – not everything, but a large range of it.”

Yet, with some operations lasting days rather than hours, there are only so many batteries that can be taken into operations. Therefore, field-based charging is critical, as the first of the GSA whitepaper series in the UK highlighted. “Understanding the potentially viable options for soldier battery charging across bases, vehicles and autonomous platforms is seen as an area that needs immediate clarity,” it stated, adding that there needed to be a better understanding of how to make use of current and future supply chain elements, power harvesting and scavenging.

One for all

Browning says one possible resource – energy harvesting solutions that draw power from kinetic energy released by a soldier’s movements – simply doesn’t meet soldiers’ needs very well. Likewise, renewable energy like solar power, although of huge interest in other realms of defence, is not suitable, largely due to its power density being far lower than traditional battery or fuel energy sources.

The reality is that for dismounted operations, conventional battery solutions are the answer – at least for now. Therefore, it will be innovations in batteries that will garner most interest, along with the power management and recharge systems that supply them. “I don’t see soldiers deploying, in my lifetime, without batteries,” predicts Browning. But, he says, batteries will get better and will be augmented by other technologies. Right now, a huge amount of work to develop new materials and enhance the density of batteries is ongoing in laboratories around the world.

“Over the next few years or so, we may be able to double the energy density of a battery, with some compromises,” Browning believes. “So, you [might] get a battery with twice the energy, but it won’t cycle quite as well and will cost more.” However, he believes that ultimately fewer compromises will be needed, saying that “when [these new batteries] get closer towards the cycle life you can expect today, the cost will come down. That’s probably the main step-change I see in soldier battery technology.”

Browning’s vision is that defence forces will eventually have centralised batteries operating soldiers’ body-worn devices, while monitoring and managing their power supply and usage. This will be enabled by standardised and interchangeable batteries, shared between the individual, their squad, the wider platoon and even allied forces. He also forecasts a future where power and data are king – brought together with a USB-C socket as standard. But there’s work to do yet.

This is where OEMs have a huge role to play. They have already been supporting the MoD in writing standards via working groups and other engagement. However, says Browning, that work so far has been focused on the battery connector. Adding that the effort to standardise batteries is early on in its journey, he says OEMs will be critical going forward by ensuring their future equipment is compatible and that there’s a resilient enough supply chain for the batteries themselves. “It’s very much a two-way journey,” he declares. “There’s no good [in] the MoD stipulating a battery if either nobody makes it, or no radio or equipment manufacturer wants to adopt it.”

How militaries around the world power the growing amount of technology they’re deploying in the field is a question everyone is trying to answer – and some may perhaps be close to doing just so. When they find that solution and what that answer might be remains uncertain, for now. However, one thing is clear – dismounted soldier technology will continue to advance and the power it needs will only keep increasing.