Soon after starting his new role as editor of BEST, James Snodgrass discovered there was a sodium battery factory tucked away in a hidden corner of his home city. So he went to investigate.
It started with a message on LinkedIn. I had announced that I had been appointed editor of this august journal and my excitement at getting the chance to cover this crucial industry. An old colleague posted: “Congratulations, you should have a chat with Colin Fulker about some of the cool battery stuff he is doing!”
So I did. And hopped into my (electric) car and drove for 20 minutes.
Falmer is an unusual place. This idyllic, rural village on the outskirts of the English coastal city of Brighton saw a population explosion in the 1960s when a new campus university, University of Sussex, was built next to the village. Falmer was then bisected in the 1990s, when the Brighton bypass section of the A27 highway was constructed, splitting the village in two. And, in 2011, this tiny village became home to a 30,000+ capacity football stadium for English football club Brighton and Hove Albion – officially known as the American Express Community Stadium (but commonly referred to as “The Amex” or “Falmer”).
So it should come as no surprise that strange little Falmer is home to Britain’s first sodium battery “factory”. The quotation marks are intentional – Beyond Batteries occupies three units in a small “industrial” estate in former agricultural buildings about a mile north of Falmer’s village centre. Its neighbours are a rifle range and grazing cattle.
When I meet Colin, I said how refreshing it was to find an industrial unit in such a bucolic setting, and not a traditional concrete-and-metal industrial estate. He sighed: “We’re growing to the point where we’re going to have to move to a proper industrial estate some time very soon.”
Colin studied mechanical engineering at university and went on to work in construction. During the first lockdown of 2020 he became obsessed with a YouTube channel called Fully Charged (now known as Everything Electric). “Basically, during lockdown, I went back to episode one, watched them all, and then when I got to about episode 120, the overriding theme of the show was: ‘you can have all the renewables in the world, but if you can’t store it, it’s useless.’ And I thought, ‘well, there you go.’”
Like so many people, Colin found lockdown was a time that allowed for reflection on new directions for his life. Unlike most people, however, Colin followed up on it. He knew that batteries were the future but wasn’t sure, at that time, which chemistry he’d opt for: “We heard all the nasty stuff about lithium. Back then [stories about] fires were quite prevalent… obviously, the oil industry was fuelling a bit of that fire… literally and metaphorically.”
He decided to start small and find a niche. As a keen skier, his thoughts turned to camper vans. Lighter means better efficiency. Colin realised that by replacing the lead-acid battery with a lithium-iron-phosphate battery it would provide the same energy density but at a lower weight.
“Camper vans were a perfect fit because that’s where you want something smaller, lighter and safer to replace lead-acid batteries,” Fulker said.
However, the company soon identified a larger opportunity in commercial applications that still rely heavily on diesel generators, particularly in the construction and environmental monitoring sectors. Instead of competing with established brands like DeWalt and Milwaukee in the power tool battery market, the company aimed to provide batteries for larger tools and equipment used in construction.
“We started focusing on areas where generators were still being used and people thought batteries were impossible,” Fulker said. “For things like CCTV on building sites, generators used to power them. Now a compact battery can do the same job.”
Environmental legislation has helped grow the market for generator replacement. London’s ULEZ (ultra low emissions zone) has created a financial disincentive for using diesel generators on site.
“Pack assembly is ultimately what our business is – not electrochemistry, none of us are layering up metal oxides and rolling them up for fun” Fulker said. “We prototype everything in-house, but the cells themselves mainly come from China because nowhere else can match the price and quality right now.
“We have a bit of flexibility. As you can see from our premises we have to be small and agile. When a new cell comes out, we can get some in, have a play, and test them to destruction on the farm.”
The battery management systems (BMS) come from different sources, including China’s Jiabida, but the company plans to develop its own BMS.
And it was from this experimentation that the company began working with sodium-ion batteries – Beyond Batteries claims to be the first UK manufacturer to commercially offer a sodium-ion battery system.
“We were the first company in the UK to make a sodium-ion battery commercially available,” Fulker said.
Sodium batteries offer advantages in safety, resource availability and sustainability compared with lithium-based chemistries, although they have lower energy density.
“Sodium is everywhere and geopolitically stable – pretty much every country has access to it,” Fulker said. “You get incredible performance and safety, but the trade-off is lower energy density compared with lithium.”
The company says its approach prioritises safety over maximum energy density, focusing on applications where reliability and durability are more important than compact size.
“We only play with chemistries that we consider safe – something I’d be happy to sleep above if it was under my bed,” Fulker said. “We don’t want to sell anything where our name can be associated with the F-word … fire.”
“The bottom line is, yes, you get significantly more energy density if you go to a more exotic chemistry. So it is a trade off. We get high performance, super high safety, but it’s not as energy dense.”
Beyond Batteries currently offers around 25 off-the-shelf products alongside bespoke systems developed for commercial customers across sectors including construction, security and environmental monitoring.
All its products are Bluetooth-enabled, allowing users to turn them on and off, and read the discharge stats, remotely, using their smartphones.
The company is also working on new products aimed at replacing lead-acid batteries used in fire alarm backup systems in commercial buildings, which are typically replaced every three-to-five years. Colin says Beyond Batteries’ cells will last for 10 years: “We’re going to build them first and get all the certifications done, and then hopefully the market will catch on to their levels of safety and longevity.”
As the interview was coming to a close, the company’s landlord popped his head around the door. Which gave us an opportunity to see some Beyond Batteries products in action. The landlord – a well-known local businessman – was keen to show me his shed. He pointed to his solar panels, which were being eyed by a herd of Sussex cattle, a local breed known for their red coats and heavy musculature, in the field above. The landlord said that the solar panels, in conjunction with a rack-mounted BESS from Beyond Batteries, allowed him to heat his swimming pool in all weathers, completely off-grid. In return, Beyond Batteries get to field-test their Sodi-Home 5kWh 48V home storage batteries.
Cows, a swimming pool, a rifle range, the whole operation felt quietly subversive: a battery company that doesn’t quite look like one, building systems that challenge long-held assumptions about what works in the field. Beyond Batteries is small, agile, and the product of lockdown curiosity – but it is also a useful reminder that the energy transition will not be delivered solely by gigafactories and global incumbents. Sometimes, it starts in a converted farm building, with a handful of cells, a willingness to test them to destruction, and a clear-eyed view of what customers actually need.
