Spring 2003: the US army barrels towards Baghdad during the Iraq invasion but the onslaught nearly grinds to a halt, not because of fierce resistance but due to a lack of batteries.
It was an unexpected crisis. Pilots recalled seeing streams of military vehicles on the country’s motorways hauling supplies including bullets, shells, food and fuel. But batteries – specifically a model called BA 5590 – were in desperately short supply. A planning oversight meant they were still en route by ship at the time of the invasion.
Military radios that allowed for everything from the orchestration of modern firepower to calling for evacuation of the wounded depended on the BA 5590.
The US army was going through 180,000 of the batteries a month. Priority was given to units in combat but it soon became clear that flying planeloads of BA 5590s to Kuwait would not be enough. In the US, inventories were draining and firms such as Ultralife Batteries were working round the clock to produce more.
Fast-forward to the present and battery power is very much on the minds of defence planners, despite leaps in technology and efficiency.
“What is being fielded today in terms of rechargeable batteries is now far superior to what used to be available as a disposable battery,” said Steve Carkner, an adviser at Galvion, a defence company focused on soldier protection and power management. "That fundamentally is what is going to create the shift you're going to see, better rechargeable batteries and more ways of recharging them."
Their technology focuses on wearable batteries that can be wirelessly charged on the move, as well as devices for “scavenging”, meaning that power can be taken “from partially discharged batteries, vehicles and standard electrical outlets, and … converted into a usable format for powering devices and recharging batteries,” according to Galvion.
That includes getting power into the field from flexible solar panels.

A unit that might be able to operate with batteries for one or two days can continue operations in remote areas for much longer, so is less likely to find itself cut off from friendly forces.
“Ten years ago, if somebody was going out on a mission and their battery said it was 80 per cent charged and it was rechargeable, they wouldn't use it. They wouldn't trust it. They would say, ‘I'm leaving that one behind. Is 80 per cent good enough?’ Today the technology is far superior and there’s a lot more trust in it,” said Mr Carkner.
The digital war
That trust is increasingly important. In Ukraine, reconnaissance drones gobble up batteries, sometimes flying for about 30 minutes to spot the enemy. Soldiers use laptops, tablets and phones to pinpoint enemy areas on maps for artillery strikes, using an app called GIS ARTA – described as “Uber for artillery”.
Battery-powered laser rangefinders calculate how far away a target is. At night, thermal imagers and night-vision goggles also need batteries. Selective Availability Anti-Spoofing Modules – hand-held military GPS receivers that resist electronic interference – have batteries that last for less than a day.

And increasingly, unmanned ground vehicles are used to drop mines or evacuate soldiers. In December, an entire Ukrainian attack was orchestrated using ground vehicles and drones, the first such assault in history. Demand for batteries in war is rising quickly.
Radios are also a critical area for battery power. Modern military radio networks are often described as “mesh networks”, where each radio serves as a router in the network, rather than relying on fixed transmission sites that could be bombed or jammed. The sprawling “mesh” can obscure where individual soldiers are to enemy electronic surveillance.
Military expert Jack Watling describes the mesh as appearing as “mist” on the screens of electronic warfare units. But the network places higher power demands on infantry radios – and their batteries.

All of this adds weight to a mission. Soldiers often carry up to 9kg of batteries to war, before adding ammunition, their rifle, water, grenades, a hand-held tactical radio and other equipment.
“In 2003 the soldiers were carrying bulky analogue radios,” says Mr Carkner, who has invented battery charging technology and now works with Tungsten Collaborative, a product design and development firm.
"They were absolute power hogs and soldiers would carry multiple batteries just for that one radio. Digital radios use only a fraction of the power and can often be powered from a source that is shared with other gear. The soldier is now loaded up with a lot of other technologies, but the ability of those technologies to operate on reduced or variable power budgets is quite astonishing."
One of the problems in the past, Mr Carkner added, was that many military batteries were customised to one system, meaning several types of each had to be carried to war, but there has now been a drive to standardise.
“Twenty years ago, military batteries would contain fully custom cells (often with tailored chemistry and construction), as well as custom electronics and mechanical cases,” he said. "All the elements of the battery design worked together to make a fully hardened battery system. These custom cells were often produced in low volume, which made them expensive and sometimes lead to quality-control issues."
But he added that it is the civilian world, rather than one run by military designers, which has enabled greater standardisation at lower cost.
“The most dramatic improvements in battery technology have been in the quality and durability of the cells themselves, largely driven by the electric vehicle industry," Mr Carkner said. "As a result, military batteries today are able to be constructed with off-the-shelf cells, often made at very high volume. The batteries still require a high level of care in the mechanical and electrical design to ensure the system, as a whole, is capable of surviving the rigours of a military environment.”
Rugged tech
Soldiers in the field and their equipment have to endure the elements, from the harsh, dusty desert environment to humid, rainy jungles or temperatures well below zero, when regular batteries rapidly fail, being sensitive to temperature extremes.
As well as water immersion, the batteries also need to be able to take shocks, from explosions to the rough and tumble of armoured vehicles moving over rocky ground.
“It is unlikely that a civilian battery would last very long in a military operation,” Mr Carkner said.
How serious the mass failure of batteries could be was laid bare in September 1944, when 10,000 British paratroopers were surrounded by German forces at Arnhem in the Netherlands.
Jeep radios were powered by generators, many of which had been damaged in fighting and soldiers were forced to use vehicle batteries in attempts to power radios. When those batteries went dead, the troops became even more isolated and were gradually picked apart by the more organised Germans.
Today, while batteries are vastly superior, there is a race to improve the technology by leaps and bounds with a next generation of solid-state batteries that could charge more quickly and with higher energy density than dominant Lithium-ion batteries. Scientists in the US, China and elsewhere are striving to achieve this breakthrough first.
“Solid state is going to still be a while and there are integration issues surrounding solid-state batteries that make them difficult to apply in all situations,” Mr Carkner said. "Smaller, lighter systems are more challenging for solid state when it comes to cold-temperature performance and high-peak powers. There are amazing places to put solid-state batteries but they don't fit everywhere. And there are a lot of military places where solid state just isn't a good fit."
Some of the US military’s most advanced projects, such as the Orca, an unmanned submarine with a near 10,000km range, will rely on Lithium-ion batteries.
“Improvements are being made in conventional rechargeable batteries, there are great advances being made. In the last five years, we've seen a shift away from a laser focus on capacity and seeing a lot more focus on performance metrics like cold-temperature and hot-temperature performance, and cycle life," Mr Carkner added.
“If you look at the growth of capacity available versus size and weight, for example, advances in current battery technology are definitely slowing down. But advances in other areas of battery technology are still doing very well – there's lots of room for improvement.”