electric vehicle

106 Articles

Thermal Runaway: Solving The Bane Of Electric Vehicles

September 17, 2024 by 86 Comments

Although battery fires in electric cars and two-wheeled vehicles are not a common phenomenon, they are notoriously hard to put out, requiring special training and equipment by firefighters. Although the full scope of the issue is part of a contentious debate, [Aarian Marshall] over at Wired recently wrote an article about how the electric car industry has a plan to make a purportedly minor issue even less of an issue. Here the questions seem to be mostly about what the true statistics are for battery fires and what can be done about the primary issue with batteries: thermal runaway.

While the Wired article references a study by a car insurance company about the incidence of car fires by fuel type (gas, hybrid, electric), its cited sources are dubious as the NTSB nor NHTSA collect statistics on these fires. The NFPA does, but this only gets you up to 2018, and they note that the data gathering here is spotty. Better data is found from European sources, which makes clear that battery electric vehicles (BEVs) catch fire less often than gasoline cars at 25 per 100,000 cars sold vs 1529/100k for ICE cars, but when BEVs do burn it’s most often (60%) from thermal runaway, which can be due to factors like a short circuit in a cell, overcharging and high ambient temperatures (including from arson or after-effects of a car crash). Continue reading “Thermal Runaway: Solving The Bane Of Electric Vehicles” →

A yellow, three wheeled vehicle with a canopy that opens upward over the body. It looks a little like the cockpit of a jet figher.

Restoring A Vintage German EV

April 21, 2024 by 44 Comments

When you think of EVs from the 90s, GM’s EV1 may come to mind, but [bleeptrack] found a more obscure CityEL three wheeler to restore.

This Personal Electric Vehicle (PEV) is no spring chicken, but a new set of LiFePO4 batteries should give its 48 V electrical system a new lease on life. [bleeptrack] shows us through the cockpit of this jet fighter-esque EV and its simple control systems, including a forward and reverse selector and the appreciable kilometers on the odometer.

Modernizing touches for this vehicle include a smart shunt to track the vehicle charge level as an improvement over the wildly unreliable original system and a new DC to DC converter after the original unit failed. These changes really cleaned up the electronics compartment from the original rat’s nest under the seat.

The design of this vehicle has us thinking of the Minimal Motoring Manifesto and how EVs could make cars simpler again.

Continue reading “Restoring A Vintage German EV” →

A finger points at a stack of yellow plastic plates sandwiched together like on a bookshelf. A grey metal rectangle holds the top together and black plastic sticks off to the left. The top of the pack has copper and nickel (or some other silver-colored metal) tabs pointing up out of the assembly.

Tearing Into A Sparky Sandwich

April 11, 2024 by 35 Comments

We’re still in the early days of modern EV infrastructure, so minor issues can lead to a full high voltage pack replacement given the lack of high voltage-trained mechanics. [Ed’s Garage] was able to source a Spark EV battery pack that had succumbed to a single bad cell and takes us along for the disassembly of the faulty module.

The Spark EV was the predecessor to the more well-known Chevy Bolt, so its nearly ten year old systems might not reflect the state-of-the-art in EV batteries, but they are certainly more modern than the battery in your great-grandmother’s Baker Electric. The Li-ion polymer pouch cells are sandwiched together with cooling and shock absorbing panels to keep the cells healthy and happy, at least in theory.

In a previous video, [Ed’s Garage] takes apart the full pack and shows how the last 2P16S module has assumed a darker color on its yellow plastic, seeming to indicate that it wasn’t receiving sufficient cooling during its life in the car. It would seem that the cooling plates inside the module weren’t quite up to the task. These cells are destined for other projects, but it doesn’t seem like this particular type of battery module would be too difficult to reassemble and put back in a car as long as you could get the right torque settings for the compression bolts.

If you’re looking for other EV teardowns, might we suggest this Tesla Model S pack or one from a passively-cooled Nissan Leaf?

Continue reading “Tearing Into A Sparky Sandwich” →

Two researchers, a white woman and dark-skinned man look at a large monitor with a crystal structure displayed in red and white blocks.

AI On The Hunt For Better Batteries

January 23, 2024 by 18 Comments

While certain dystopian visions of the future have humans power the grid for AIs, Microsoft and Pacific Northwest National Laboratory (PNNL) set a machine learning system on the path of better solid state batteries instead.

Solid state batteries are the current darlings of battery research, promising a step-change in packaging size and safety among other advantages. While they have been working in the lab for some time now, we’re still yet to see any large-scale commercialization that could shake up the consumer electronics and electric vehicle spaces.

With a starting set of 32 million potential inorganic materials, the machine learning algorithm was able to select the 150 most promising candidates for further development in the lab. This smaller subset was then fed through a high-performance computing (HPC) algorithm to winnow the list down to 23. Eliminating previously explored compounds, the scientists were able to develop a promising Li/Na-ion solid state battery electrolyte that could reduce the needed Li in a battery by up to 70%.

For those of us who remember when energy materials research often consisted of digging through dusty old journal papers to find inorganic compounds of interest, this is a particularly exciting advancement. A couple more places technology can help in the sciences are robots doing the work in the lab or on the surgery table.

Continue reading “AI On The Hunt For Better Batteries” →

Tesla’s Plug Moves Another Step Closer To Dominance

December 21, 2023 by 46 Comments

Charging an EV currently means making sure you find a station with the right plug. SAE International has now published what could be the end to the mishmash of standards in North America with the J3400 North American Charging Standard.

The SAE J3400TM North American Charging Standard (NACS) Electric Vehicle Coupler Technical Information Report (TIR), which just rolls off the tongue, details the standard formerly only available on Tesla vehicles. We previously talked about the avalanche of support from other automakers this year for the connector, and now that the independent SAE standard has come through, the only major holdout is Stellantis.

Among the advantages of the NACS standard over the Combined Charging System (CCS) or CHAdeMO is a smaller number of conductors given the plug’s ability to carry DC or AC over the same wires. Another benefit is the standard using 277 V which means that three separate Level 2 chargers can be placed on a single 3-phase commercial line with no additional step down required. Street parkers can also rejoice, as the standard includes provisions for lampost-based charger installations with a charge receptacle plug instead of the attached cable required by J1772 which leads to maintenance, clutter, and ADA concerns.

Now that J3400/NACS is no longer under the purview of a single company, the Federal Highway Administration has announced that it will be looking into amending the requirements for federal charger installation subsidies. Current rules require CCS plugs be part of the installation to qualify for funds from the Bipartisan Infrastructure Bill.

If you want to see how to spice up charging an EV at home, how about this charging robot or maybe try fast charging an e-bike from an electric car plug?

An image of the inside of a vehicle wheel. An outer ring gear is attached to two articulated sets of three small helical gears attached to a central sun gear. A shaft from the right side enters into the sun gear.

A Revolution In Vehicle Drivetrains?

December 6, 2023 by 47 Comments

Power delivery in passenger vehicle drivetrains hasn’t changed much since the introduction of the constant velocity (CV) joint in the 1930s. Most electric vehicles still deliver power via the same system used by internal combustion cars. Hyundai/Kia has now revealed a system they think will provide a new paradigm with their Universal Wheel Drive System (Uni Wheel). [via Electrek]

What appears at first to be a hub motor is in fact a geared wheel that keeps the motor close without the problem of high unsprung weight. Power is fed into a sun gear which can move independently of the wheel allowing the system to maintain a more consistent driveline and avoid power variability over the range of suspension travel like you’d find in a CV joint experiencing high deflection.

We have some concerns about the durability of such a system when compared with the KISS and long development history of CV joints, but we can’t deny that moving the motors of an electric vehicle out to the corners would allow more packaging flexibility for the cargo and passenger areas. We’re also excited to see open source replicas make their way into smaller robotics projects now that the images have been released. If you’ve already made one in CAD, send us a tip at tips@hackaday.com.

Looking for more interesting innovations in electric cars? How about an off-grid camper van? If you think automakers are overcomplicating something that should be simple, read the Minimal Motoring Manifesto.

Continue reading “A Revolution In Vehicle Drivetrains?” →

An ebike motor with the controller cover removed. A number of wires and connectors take up most of the space in the cavity.

Open Brain Surgery For EBikes And EScooters

November 6, 2023 by 7 Comments

Personal Electric Vehicles (PEVs) all contain the same basic set of parts: a motor, a battery, a motor controller, some sensors, and a display to parse the information. This simplicity allowed [casainho] to develop a custom controller setup for their own PEVs.

Built around the venerable VESC motor controller, [casainho]’s addition is the EBike/EScooter board that interfaces the existing motor of a device to the controller. Their ESP32-powered CircuitPython solution takes the sensor output of a given bike or scooter (throttle, cadence, or torque) and translates it into the inputs the controller uses to set the motor power.

They’ve also designed an ESP32-based display to interface the rest of the system to the user while riding. Since it also runs CircuitPython, it’s easy to reconfigure the functions of the three button device to display whatever you’d like as well as change various drive modes of your system. I know I’d love to see my own ebikes have a different mode for riding on road versus on shared paths since not getting run over by cars and not harassing pedestrians aren’t going to have the same power profile.

If you want to find more ways to join the PEV revolution, check out this wild omni-wheeled bike or this solar car built from two separate e-bikes. If that doesn’t suit your fancy, how about an off-label use for an e-bike battery to power your laptop off grid?