Skip to main content

Lithium-ion vs. NiMH: EV batteries explained and compared

The automotive industry is quickly accelerating towards electrification, with electric vehicles, or EVs, paving the way. Of course, a critical component of every EV is the battery, which powers everything about an EV — from the electric motors to the infotainment system, to the air conditioning.

But did you know there are actually different types of electric car batteries? As development on EVs continues, battery technology is shifting and evolving, helping push for cars with longer ranges.

Recommended Videos

So what are the different types of electric car batteries? There are two major types you need to know about, and each has its own benefits and drawbacks. Here’s a rundown.

Lithium-ion batteries

Front three-quarters view of a 2023 Kia EV6 GT in a desert setting.
Christian de Looper / Digital Trends

Lithium-ion batteries have become the dominant choice for powering EVs, offering a range of advantages over other battery technologies. One of the most significant benefits of lithium-ion batteries is their high energy density, which allows electric cars to travel longer distances on a single charge. Not only that, but lithium-ion batteries have a relatively low self-discharge rate, ensuring that the stored energy remains available for an extended period, even when the vehicle is not in use.

However, lithium-ion batteries also present some challenges for the EV industry. One of the primary concerns is the limited availability of raw materials, such as lithium and cobalt, which are crucial for battery production. The mining of these materials often has environmental and ethical implications. And, the production process of lithium-ion batteries generates a substantial carbon footprint, which can negate some of the environmental benefits of electric vehicles.

Performance over time is also somewhat of a concern. The performance of lithium-ion batteries tends to degrade over time, resulting in reduced range and charging capacity. This can lead to increased costs for consumers who need to replace the battery pack. Despite these issues, companies are continuing to research and develop lithium-ion batteries, and they’re set to get better and better over time.

Nickel-metal hydride batteries

Front view of the 2022 Jeep Grand Cherokee 4xe plug-in hybrid.
Stephen Edelstein/Digital Trends

Nickel-metal hydride (NiMH) batteries have long been a popular choice for hybrid cars and have also been utilized in some EVs. One of the primary advantages of NiMH batteries is their robustness and durability. These batteries have a long cycle life, which means they can endure many charge and discharge cycles before their performance begins to decline. Not only that, but NiMH batteries can deliver high levels of power output, enabling quick acceleration and overall strong performance in hybrid cars and EVs.

There are some notable disadvantages associated with NiMH batteries when compared to other battery technologies. NiMH batteries have a lower energy density, meaning they store less energy per unit of weight or volume. This translates to reduced driving ranges, which can be a significant drawback for consumers concerned about range anxiety. And, NiMH batteries have a higher self-discharge rate than lithium-ion batteries, which means they can lose a more significant portion of their stored energy when not in use. This characteristic can be particularly problematic for EVs that are parked for extended periods.

Another downside of NiMH batteries is their sensitivity to extreme temperatures. High temperatures can negatively impact their performance and lifespan, while low temperatures can reduce their ability to deliver power. This limitation can present challenges in regions with varying climates. Although NiMH batteries do not rely on scarce materials like cobalt and lithium, their production still involves the use of nickel, which can raise environmental and ethical concerns surrounding mining practices.

Generally, it’s not expected that these batteries will be used more in EVs — but they could continue being used in hybrid cars that don’t necessarily require a higher energy density.

Christian de Looper
Christian de Looper is a long-time freelance writer who has covered every facet of the consumer tech and electric vehicle…
Tesla posts exaggerate self-driving capacity, safety regulators say
Beta of Tesla's FSD in a car.

The National Highway Traffic Safety Administration (NHTSA) is concerned that Tesla’s use of social media and its website makes false promises about the automaker’s full-self driving (FSD) software.
The warning dates back from May, but was made public in an email to Tesla released on November 8.
The NHTSA opened an investigation in October into 2.4 million Tesla vehicles equipped with the FSD software, following three reported collisions and a fatal crash. The investigation centers on FSD’s ability to perform in “relatively common” reduced visibility conditions, such as sun glare, fog, and airborne dust.
In these instances, it appears that “the driver may not be aware that he or she is responsible” to make appropriate operational selections, or “fully understand” the nuances of the system, NHTSA said.
Meanwhile, “Tesla’s X (Twitter) account has reposted or endorsed postings that exhibit disengaged driver behavior,” Gregory Magno, the NHTSA’s vehicle defects chief investigator, wrote to Tesla in an email.
The postings, which included reposted YouTube videos, may encourage viewers to see FSD-supervised as a “Robotaxi” instead of a partially automated, driver-assist system that requires “persistent attention and intermittent intervention by the driver,” Magno said.
In one of a number of Tesla posts on X, the social media platform owned by Tesla CEO Elon Musk, a driver was seen using FSD to reach a hospital while undergoing a heart attack. In another post, a driver said he had used FSD for a 50-minute ride home. Meanwhile, third-party comments on the posts promoted the advantages of using FSD while under the influence of alcohol or when tired, NHTSA said.
Tesla’s official website also promotes conflicting messaging on the capabilities of the FSD software, the regulator said.
NHTSA has requested that Tesla revisit its communications to ensure its messaging remains consistent with FSD’s approved instructions, namely that the software provides only a driver assist/support system requiring drivers to remain vigilant and maintain constant readiness to intervene in driving.
Tesla last month unveiled the Cybercab, an autonomous-driving EV with no steering wheel or pedals. The vehicle has been promoted as a robotaxi, a self-driving vehicle operated as part of a ride-paying service, such as the one already offered by Alphabet-owned Waymo.
But Tesla’s self-driving technology has remained under the scrutiny of regulators. FSD relies on multiple onboard cameras to feed machine-learning models that, in turn, help the car make decisions based on what it sees.
Meanwhile, Waymo’s technology relies on premapped roads, sensors, cameras, radar, and lidar (a laser-light radar), which might be very costly, but has met the approval of safety regulators.

Read more
Scout Traveler SUV vs. Rivian R1S: modern electric SUVs compared
Scout Motors Traveler SUV in a forest

Scout Motors has made a big comeback, now under the guidance of Volkswagen Group. Not only is the Scout brand being reinvigorated but it has already announced two new models in the form of the Scout Terra truck and the Scout Traveler SUV. The Scout Traveler SUV in particular is an interesting vehicle, but it has an uphill battle ahead of it thanks to competition from the likes of Rivian.

The Rivian R1S is often considered to be the best electric SUV out there right now, and while it's not cheap, it offers an excellent set of tech features, a long range, and more. So how does the Scout Traveler SUV compare with the R1S? We put the two vehicles head to head to find out.
Design
The exterior designs of the Scout Traveler and the Rivian R1S are similar in many ways, though there are some major differences. Both vehicles offer a relatively blocky shape characteristic of a traditional SUV. The Traveler is a little more traditional than the Rivian in that it has a spare tire on the back, which is both practical and gives it a rugged vibe.

Read more
Waymo, Nexar present AI-based study to protect ‘vulnerable’ road users
waymo data vulnerable road users ml still  1 ea18c3

Robotaxi operator Waymo says its partnership with Nexar, a machine-learning tech firm dedicated to improving road safety, has yielded the largest dataset of its kind in the U.S., which will help inform the driving of its own automated vehicles.

As part of its latest research with Nexar, Waymo has reconstructed hundreds of crashes involving what it calls ‘vulnerable road users’ (VRUs), such as pedestrians walking through crosswalks, biyclists in city streets, or high-speed motorcycle riders on highways.

Read more