Chevy Bolt EV’s Battery Is As Big As A Tesla’s

When it goes on sale later this year, the $37,500 Chevy Bolt will be the first electric car priced in the realm of a Nissan Leaf but with battery about as big as an entry level Tesla Model S.

The Bolt’s 60-kwh pack is actually the size of what was supplied in the outgoing 208-mile range Model S 60 which sold through 2015 and which was replaced with a 70-kwh pack.

General Motors says the Chevy Bolt EV will get more than 200 miles range – a credible estimate and perhaps the only question remaining is how much more?

Incidentally, from its launch Tesla had originally planned to sell a 40-kwh Model S but canceled it after receiving too few pre-orders. And, while Tesla is a large luxury performance sedan offering other advantages over the Bolt, what GM is offering is an indicator of how far it has increased what can be expected in this “mass” market class of EV.

The Bolt’s LG Chem li-ion battery made along with its drive unit and motor in Incheon, South Korea utilizes cells for which GM pays a comparatively paltry $145/kwh which helps it give this much bang for the buck.

Undisclosed is the usable energy of the Bolt’s battery, a critical parameter affecting range, and based on how it set up its Chevy Volt and Spark EV, GM has certainly made it a priority to not over-tax the battery which could threaten it with too-rapid degradation in its lifetime.

For what it’s worth, Tesla allows over 90-percent usable capacity if you put it in “range mode” for a road trip. GM has historically allowed less but the Bolt’s “buffer” has not been revealed.

Another factor is curb weight. The Bolt is surprisingly light at 3,580 pounds, several hundred pounds lighter than the Tesla 60, but ultimately, until GM comes out and states it, EPA range remains a mystery.

Compact Crossover / Small Wagon

But that is largely where the Bolt comparison to a Tesla Model S ends as Bolt is positioned as quite a different car. The automaker must call it a “small wagon” for EPA purposes as no crossover category is in place with the government, but GM has also called it informally a compact crossover.

And whether the case exists for “crossover” versus hatchback, calling it the former may serve to position the Bolt away from those who would – and some readers have – find fault with an economical “hatchback” selling for close to $40,000 before incentives.

While media reviews have been complimentary, reader comments from around the ‘Net have varied from also enthusiastic to some openly wondering about the value proposition.

In any event, the Bolt has excellent interior space utilization and is near a midsize car by volume. Its flat battery does not intrude in the interior space and other techniques to squeeze precious useable space on a compact platform include thin seat backs and low-cut door sills for ingress/egress, along with other smart packaging.

Comparatively Speedy

And, to further distinguish it from more pedestrian eco cars, GM notes its drive experience is “more akin to a compact sports sedan than a small utilitarian crossover,” with 0-60 estimated under 7 seconds thanks to good power and 7.05:1 final drive ratio.

Specifically, a single high-capacity motor delivers an estimated 200 horsepower (150kw) and 266 pounds-feet (360 Nm) of torque. A shift-by-wire system separates it from the battery pack – see animated exploded view video for further details.

And however you slice it, the Bolt is also being positioned as a fun-to-drive car.

“Being the leader in range and affordability means nothing if the car isn’t going to excite you each time you get behind the wheel,” said Josh Tavel, Chevrolet Bolt EV chief engineer. “That’s why the team was tasked with delivering a propulsion system that would also make the Bolt EV an electric vehicle that owners would love to drive.”

The in-floor pack also lowers center of gravity and is said to contribute toward handling dynamics.

Weight for the battery assembly in total is 960 pounds (435 kg). It utilizes 288 lithium-ion cells separated into five sections, 10 modules and 96 cell group – three cells per group.

“You usually have a battery cell that delivers either the desired levels of energy or power, but not traditionally both. With this cell design and chemistry we were able to deliver a battery system with 160 kilowatts of peak power and 60 kilowatts hours of energy,” said Gregory Smith, Bolt EV battery pack engineering group manager.

The automaker is also touting a new cell design and nickel-rich lithium-ion chemistry said to offer improved thermal operating performance. Because of this, the new chemistry requires a smaller active cooling system and in turn enables more efficient packaging.

An ongoing criticism of battery powered cars has been susceptibility to cold outside air temperatures. GM says its new chemistry allows the Bolt “to maintain peak performance in varying climates and driver demands.”

Warranty is 8-years, 100,000 miles on the battery that uses active thermal management – unlike the Nissan Leaf, but like the Chevy Volt.

A 7.2-kw onboard charger enables overnight charging from standard 240-volt electric vehicle service equipment (AKA “charger”). Fifty miles worth of driving range can be replenished in two hours, Chevrolet notes, and DC fast charging can also rapidly replenish the pack. The automaker says 90 miles of range in 30 minutes depending on ambient temperatures.

One-Pedal Driving

As plug-in cars are already accustomed to, the Bolt is a vehicle that can save brake pads quite a bit.

Its regenerative braking including regen paddle that serves to slow the car and send current back to the battery enables much of the stopping to be done without using the friction brakes.

A “low” mode also adds to the effect which significantly increases regen braking action upon deceleration.

The automaker says a driver can completely stop the Bolt “under most circumstances” by lifting off the accelerator.

“Interviews with EV enthusiasts indicated their desire for one pedal driving capability on the Bolt EV,” Tavel said. ” One pedal operation boosts the thrill and uniqueness of EV driving.”

Chevrolet says it augmented the capability by both increased regenerative deceleration and software controls. This does not do away with the need for regular brakes, but under normal driving can work in lieu and is an elegant advantage over conventional internal combustion vehicles.

Instead of wasting energy every time the car slows down as friction heat on the pads and rotors, the motor takes that kinetic energy and gives a tad more battery charge and thus range.

It’s also convenient as braking can be by the fingertips on the paddle, and not with the brake pedal.