Lithium batteries have taken over as the primary battery chemistry from applications ranging from consumer electronics to electric vehicles and all kinds of other things in between. But the standard lithium ion battery has a few downsides, namely issues operating at temperature extremes. Lead acid solves some of these problems but has much lower energy density, and if you want to split the difference with your own battery you’ll need to build your own lithium iron phosphate (LiFePO4) pack.
[Well Done Tips] is building this specific type of battery because the lead acid battery in his electric ATV is on the decline. He’s using cylindrical cells that resemble an 18650 battery but are much larger. Beyond the size, though, many of the design principles from building 18650 battery packs are similar, with the exception that these have screw terminals so that bus bars can be easily attached and don’t require spot welding.
With the pack assembled using 3D printed parts, a battery management system is installed with the balance wires cleverly routed through the prints and attached to the bus bars. The only problem [Well Done Tips] had was not realizing that LiFePO4 batteries’ voltages settle a bit after being fully charged, which meant that he didn’t properly calculate the final voltage of his pack and had to add a cell, bringing his original 15S1P battery up to 16S1P and the correct 54V at full charge.
The Rad Power Bikes retail shop in Huntington Beach, Calif. (Rad Power Bikes Photo)
A fire broke out at a Rad Power Bikes retail location in Huntington Beach, Calif., on Sunday, drawing more attention to the Seattle-based e-bike company’s recent setbacks.
The Huntington Beach Fire Department responded to a two-alarm structure fire at a plaza housing the store on Pacific Coast Highway. Video streamed on YouTube shows firefighters dealing with the incident, and at least two e-bikes can be seen lying on the ground outside the facility. A photo on Facebook showed smoke rising from the building, which also contains an Equinox gym.
“We’re working with local authorities to review a thermal incident that occurred at our Huntington Beach store Sunday evening,” a Rad spokesperson told GeekWire. “The incident was contained and happened while the store was closed. The cause of the fire has not been confirmed.”
The fire comes in the midst of a rough period for the once high-flying Rad Power Bikes. The startup filed for Chapter 11 bankruptcy protection in December following surprising news in November that the company was fighting for survival as it faced “significant financial challenges.”
The U.S. Consumer Product Safety Commission (CPSC) issued a warning to consumers less than two months ago to stop using some of the company’s bikes because of danger posed by their lithium-ion batteries. The CPSC warning mentioned 31 reports of fire, with 12 involving property damage.
“Some of these incidents occurred when the battery was not charging, the product was not in use, and the product was in storage,” the report stated.
In a statement at the time, Rad said it “firmly stands behind our batteries and our reputation as leaders in the e-bike industry, and strongly disagrees with the CPSC’s characterization of certain Rad batteries as defective or unsafe.”
A new phone leak shows a mini rear display beside the camera, letting you frame selfies with the main sensor. Big battery and Android 16 are listed, but price and launch regions are still missing.
The balance bikes toddlers are rocking these days look like great fun, but not so great in the snow. Rather than see his kid’s favourite toy relegated to shed until spring, [John Boss] added electric power, and an extra wheel to make one fun-looking snow trike. Like a boss, you might say.
Physically, the trike is a delta configuration: two rear wheels and one front, though as you can see the front wheel has been turned into a ski. That’s not the most stable configuration, but by shifting the foot pegs to the front wheel and keeping the electronics down low, [John] is able to maintain a safe center of gravity. He’s also limiting the throttle so kiddo can’t go dangerously fast– indeed, the throttle control is in the rear electronics component. The kid just has a big green “go” button.
Bit-banging the throttle, combined with the weight of the kiddo up front, creates a strong tendency towards wheel-spin, but [John] fixes that with a some cleverly printed TPU paddles zip-tied to the harbor-freight wheels and tires he’s hacked into use. Those wheels are fixed to a solid axle that’s mounted to flat plate [John] had made up to attach to the bike frame. It’s all surprisingly solid, given that [John] is able to demonstrate the safety factor by going for a spin of his own. We would have done the same.
Windsurfing has experienced a major decline in popularity in the last few decades as the sport’s culture failed to cater to beginners at the same time that experienced riders largely shifted to kiteboarding. While it’s sad to see a once-popular and enjoyable sport loose its mass market appeal, it does present a unique opportunity for others as there’s cheap windsurfing gear all over the online classifieds now. [Dane] recently found that some of these old boards are uniquely suited to be modified into electric surfboards.
The key design element of certain windsurfers that makes this possible is the centerboard, a fin mounted on the windsurfer extending down into the water that resists the lateral force of the sail, keeping the board moving forward instead of sideways. [Dane] used this strengthened area of the board to mount a submerged electric motor, with all of the control electronics and a battery on the top of the board. The motor controller did need a way to expel excess heat while being in a sealed waterproof enclosure, but with a hole cut in the case and a heat sink installed on top of it, this was a problem quickly solved.
The operator control consists of a few buttons which correspond to pre-selected speeds on the motor. There’s no separate control input for steering, though; in order to turn this contraption the operator has to lean the board. With some practice it’s possible to stand up on this like any other electric surfboard and scoot around [Dane]’s local lake. For the extreme budget version of this project be sure to check out [Ben Gravy]’s model which involves duct taping two cheap surfboards together instead.
A Rad Power Bikes e-bike owned by Eric Stahl of San Francisco, parked in his garage next to a DIY battery containment solution made out of cinderblocks that he hopes would help contain a battery fire if one started. (Photo courtesy of Eric Stahl)
A Rad Power Bikes rider, alarmed by reports of e-bike lithium-ion battery fires, shared a homemade storage solution on Reddit this week, sparking a broader discussion about how to safely store the devices.
The post, shared in a Rad Power Bikes forum, shows a battery placed inside stacked and capped cinder blocks — a low-cost, do-it-yourself attempt to contain a potential fire. The idea resonated with riders who said they were uneasy about storing high-powered batteries inside homes, even as others questioned whether the setup would actually work.
Eric Stahl of San Francisco has owned his Rad Runner Plus e-bike since 2021. For the past couple of days he’s been engaged in a back-and-forth debate with “armchair engineers” about his solution.
“What I put on Reddit is a cheap, DIY, common sense solution,” he told GeekWire. “It’s not tested. It’s not proven. I’m not an engineer or an expert. So everyone needs to proceed at their own risk.”
The fire concerns come amid heightened scrutiny of e-bike battery safety. Last November, the U.S. Consumer Product Safety Commission issued a warning urging consumers to immediately stop using specific lithium-ion batteries for several Rad Power Bikes models, saying the batteries could “unexpectedly ignite and explode” and pose a fire hazard. The warning followed dozens of reports of battery-related incidents and property damage.
Seattle-based Rad Power Bikes disputed the agency’s characterization and declined to agree to a recall. Since then, the once high-flying startup has entered into bankruptcy protection and is in danger of an imminent shutdown following surprising news in November that it was fighting for survival amid “significant financial challenges.”
Seattle Fire Department officials say the anxiety among riders is understandable as lithium-ion batteries used in e-bikes and other micromobility devices have become a growing fire-safety concern.
“Lithium-ion batteries store a lot of energy in a compact device,” SFD Public Information Officer David Cuerpo told GeekWire. He said they can burn extremely hot and very fast when failures occur.
Seattle firefighters began formally tracking lithium-ion battery fires in 2022. Last year, the department responded to 43 fires involving batteries, according to Cuerpo. Those incidents involved a range of devices, from phones and laptops to e-bikes and scooters.
Fires can be triggered by physical damage to batteries, corrosion, electrical failure, or exposure to extreme temperatures. When a battery fails, heat can spread rapidly from one cell to another, potentially creating a cascading fire.
Depending on where bikes and batteries are stored in the home, Cuerpo cautioned that improvised solutions can introduce new hazards.
Without full details on the cinder block setup shown on Reddit, Cuerpo said it did not appear to be a foolproof solution he would recommend.
“When a lithium battery catches fire, it can burn in excess of 1,800 degrees Fahrenheit. That’s really, really hot, and that burns very, very quickly,” he said.
Another major concern is the release of toxic, flammable gases during a battery fire. A homemade solution that’s not airtight could increase the risk that dangerous fumes escape into an enclosed space.
Eric Stahl’s e-bike battery inside his cinderblocks, and then capped with another block that he hopes would at least slow the spread of any potential fire. (Photos courtesy of Eric Stahl)
Stahl said his main goal was to prevent a fire from spreading to his house.
“I have it in my garage with a smoke detector above it, so if I’m home, I’ll hear the detector, see/smell the smoke and open the garage door if needed. If I’m not home I’m less worried about the fumes,” he said.
Even when flames appear to be out, the danger may not be over, Cuerpo cautioned. Seattle firefighters have encountered batteries that reignited hours or days after an initial fire, as undamaged cells continued to heat up.
Cuerpo recommends storing lithium-ion batteries in a cool, dry location out of direct sunlight, ideally in a garage and away from combustible materials. Commercial storage containers designed specifically for lithium-ion batteries are the safest option, though he acknowledged they can be expensive. A number of fire-retardant battery bags and certified fire-resistant storage boxes — some tested to independent safety standards — are sold online and through specialty retailers.
Cuerpo also urged riders to use manufacturer-approved chargers or equipment tested by independent certification agencies.
Batteries should be checked at least once a month for warning signs such as swelling, cracks, unusual heat, residue, or odors. Damaged batteries should never be thrown in the trash, where they can ignite fires when crushed in compactors or garbage trucks. In Seattle, residents can dispose of lithium-ion batteries at hazardous waste facilities operated by Seattle Public Utilities.
Rad provides battery safety guidance on its website, advising riders how to store batteries, to follow recommended charging practices, and to consult its battery guide and owner’s manuals for proper handling.
Stahl, who said his Rad battery model number showed up on the Consumer Product Safety Commission’s warning list, is careful about how he handles his device.
“It’s not good to drop them or get them soaking wet, but mine has been on my bike the whole time I’ve had it,” he said. “If it was cracked or bulging I would definitely get rid of it.”
He’s eager for someone to actually test his cinderblock solution with a real (safely monitored) battery fire, and maybe post their findings in a video on YouTube.
“There is so much bad information on the internet about this stuff. I just want truth-seeking,” Stahl said. “It would be a huge public service for someone to test it — and if it works, get the word out.”
Hyviva co-founder and CEO Chris Muench explains the modular design for his startup’s energy storage device. (GeekWire Photo / Lisa Stiffler)
“All this started with a really hot summer day in ’21,” said Chris Muench, sitting in a small conference room at Hyviva, his startup based in Redmond, Wash.
The Pacific Northwest was being scorched in a heat dome and Muench’s power went out at his home in nearby Duvall. The experience led him to purchase solar panels, but he also wanted to capture the excess power that was generated when the sun was shining its brightest, socking it away for when it wasn’t.
That led Muench and his wife, Sanja, to launch Hyviva in 2023. While many companies use the excess solar power to charge traditional batteries that hold the energy, this startup is harnessing the surplus power to turn water into hydrogen and storing that. The hydrogen is then turned back into energy via fuel cells when the electricity is needed.
This month, the business is shipping its first devices to customers.
Hyviva is initially targeting residential solar installations, a potentially ripe market as long-standing policies allowing homeowners to sell their unneeded solar power back to utilities are being phased out in many places. That excess power can total 20% or more of a household’s daily energy generation, according to a solar trade group.
“That’s the catalyst for storage,” said Paul Owen, chief marketing officer. “You’ve got this opportunity that’s going to waste right now.”
Stored solar power can also reduce a home’s reliance on utility-provided electricity — which is getting more expensive — and keep the lights on and fridge running during power outages.
A hydrogen storage solution
The Hyviva team alongside one of their energy storage units, from left: co-founders Sanja and Chris Muench; Mark Edin, vice president of engineering; COO John Traynor; and Paul Owen, chief marketing officer. (GeekWire Photo / Lisa Stiffler)
Hyviva’s device is a little narrower than a standard refrigerator, built from stacked units with a shiny black casing. Here’s how it works:
Water plumbed into the system goes into an electrolyzer that splits it into hydrogen and oxygen. The excess energy from the solar panels essentially powers the electrolyzer.
The hydrogen flows into slender, stainless steel tanks containing a metal that binds the gas, forming a metal hydride that stores the hydrogen.
When power is needed, the metal hydride is heated, releasing the hydrogen that flows into fuel cells that convert it to electricity.
All of the electrical and plumbing hardware are integrated into the structure of the unit, so installation requires little skilled labor.
Because of their modularity, the systems are easy to expand to increase storage capacity.
“Every module can be plugged into another module without the need of a hydrogen expert,” Chris Muench said. “Just ‘Lego brick’ them together, and then you decide how much power draw do you want, how much storage do you want, how much hydrogen you want to generate.”
The Hyviva technology connects to an existing solar system’s inverter, which manages electricity flow. The startup’s software then optimizes the flow of energy into the home, balancing inputs from the grid, solar panels and the storage device.
The five-person company is promoting its technology online and was at the CES (Consumer Electronics Show) in Las Vegas last January. Hyviva’s initial customers are in Europe and the first units are being built in Germany. The startup can also do manufacturing in Redmond for U.S. customers.
Costs and competition
Hyviva’s biggest U.S. rival is the Tesla Powerwall system that uses conventional lithium-ion batteries to hold power. The company reported $7.4 billion in revenue last year from energy generation, and that number has continued to climb.
Hyviva touts its product’s competitive features across performance, safety and longevity. The startup’s basic system holds more power — 33.6 kilowatt hours to Tesla’s 13.5 kWh. While blazes are uncommon, lithium ion batteries pose a fire risk that’s greater than the hydrogen present in a Hyviva device for short periods. And conventional batteries lose capacity over time, while the metal hydride retains its hydrogen storage capabilities for decades.
The startup, however, faces big hurdles when it comes to costs.
Tesla’s Powerwall 3 costs roughly $15,000, including the system and installation costs, while a Hyviva unit is priced at about $40,000.
But when it comes to scaling the storage capacity, the cost advantage flips as it’s cheaper and easier to add hydrogen storage to the Hyviva system. So a 90-kilowatt hour setup is about $50,000 for the startup, while the company estimates a comparable Tesla system would cost $82,000 installed.
To put the capacity in perspective, a U.S. single-family household consumes around 80 kilowatt hours of power per day on average. The cost benefits of the larger deployments continue amplifying for commercial- and industrial-scale applications, the company said.
The broader picture
As power demand keeps expanding globally, experts estimate that $1.2 trillion worth of battery energy storage will be needed through 2034. That escalating need is reflected in pockets of growth in the sector, including a Texas startup called Base Power that leases batteries to homeowners and recently announced $1 billion in new funding. And energy storage is being paired with data centers to reduce their power grid impacts, including at an Oregon campus that’s installing 31 megawatts of batteries.
At the same time, Hyviva and others face political headwinds at the federal level as the current administration pushes policies and budgets that hobble renewable energy companies and deployments.
But the startup is attracting interest, said Chief Operations Officer John Traynor. It has funding from an angel investor and reports having dozens of potential customers, with commercial sites and utilities reaching out as well.
“That’s given us the confidence that we’re on the right track,” Traynor said.
Editor’s note: Story updated to elaborate on how the energy storage system works.
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