Battery Electric Vehicle News / Enjoying the Transportation Revolution

QrizB

Panasonic has developed an advanced prototype battery for Tesla cars with five times the capacity of standard ones.

Cheaper batteries are great but the "five times the capacity" isn't strictly apples with apples. If Tesla's current cells are 21700 form format, and the new ones are 46800, the new cells have five times the volume, so you'll only fit 1/5th as many into any given volume/mass. We're still a long way from 2000-mile-range Teslas.

Martyn1981

QrizB said:

Panasonic has developed an advanced prototype battery for Tesla cars with five times the capacity of standard ones.

Cheaper batteries are great but the "five times the capacity" isn't strictly apples with apples. If Tesla's current cells are 21700 form format, and the new ones are 46800, the new cells have five times the volume, so you'll only fit 1/5th as many into any given volume/mass. We're still a long way from 2000-mile-range Teslas.

Yeah, those numbers reminded me of Battery Day, both the 5x greater volume and the 50% price reduction,

this article from Cleantechnica at the time has most of the info and some of the key slides that were shown.

Everything You Need To Know About Tesla’s New 4680 Battery Cell

So the good news is that Panasonic seem to be progressing well, hopefully, with the battery size and design.

Looking at some of the photos from GigaFest in Berlin, the structural pack with seats mounted to it, look to be using the 4680, even if it is just a mock up for now.

Ohhhhhhhhhhh so exciting!

JKenH

QrizB said:

Panasonic has developed an advanced prototype battery for Tesla cars with five times the capacity of standard ones.

Cheaper batteries are great but the "five times the capacity" isn't strictly apples with apples. If Tesla's current cells are 21700 form format, and the new ones are 46800, the new cells have five times the volume, so you'll only fit 1/5th as many into any given volume/mass. We're still a long way from 2000-mile-range Teslas.

If I have done my maths right the new cell has 5.5x the volume so 5x the energy storage isn’t anything to write home about. I thought that at the time the 4680 was announced (Battery Day) but it was being promoted as such an improvement I thought I must be missing something. 

5 x the life is impressive but that wasn’t the original selling point.

Grumpy_chap

Surely, the ideal approach is not to achieve longer range through simply having bigger batteries, but to achieve longer range through having more efficient cars (reducing losses between plug to road).

The largest batteries currently are around 100 kWh / 400 mile range.  A UK domestic single-phase installation can only charge at slightly more than 7kW, so an empty-to-full charge is 14 hours which leaves 10 hours in the day to cover leaving for work right back to home to the family.  A larger battery that takes any longer to achieve an overnight charge seems of limited benefit in the majority of cases.

However, a car that can cover 800 miles on that same 100 kWh battery - then we'd be talking

silverwhistle

Grumpy_chap said:   However, a car that can cover 800 miles on that same 100 kWh battery - then we'd be talking

My Ev has heated seats and around 160 miles of range, will that one also have a built in commode?

Grumpy_chap

Cheaper EVs are on the way in only 2 years apparently, unless the manufactures decide to just not bother with the UK:
https://www.honestjohn.co.uk/news/driving-1/2021-10/zev-mandate-new-electric-car-prices-could-drop-by-20-per-cent/

silverwhistle said:

My Ev has heated seats and around 160 miles of range, will that one also have a built in commode?

Maybe with self-drive technology and a camper-van style, it will be like a sleeper train, but a car doing full door-to-door

The serious point was around energy efficiency being the solution, not higher capacity batteries.

QrizB

Grumpy_chap said:

The serious point was around energy efficiency being the solution, not higher capacity batteries.

Energy efficiency has been an aspect of automotive engineering for the past ~50 years, since the 70s oil crisis. Any improvements on that front are likely to be incremental, not revolutionary.

Grumpy_chap

QrizB said:

Grumpy_chap said:

The serious point was around energy efficiency being the solution, not higher capacity batteries.

Energy efficiency has been an aspect of automotive engineering for the past ~50 years, since the 70s oil crisis. Any improvements on that front are likely to be incremental, not revolutionary.

To what extent are EVs early on that development curve?

2nd_time_buyer

Grumpy_chap said:

QrizB said:

Grumpy_chap said:

The serious point was around energy efficiency being the solution, not higher capacity batteries.

Energy efficiency has been an aspect of automotive engineering for the past ~50 years, since the 70s oil crisis. Any improvements on that front are likely to be incremental, not revolutionary.

To what extent are EVs early on that development curve?

There is very little scope to increase efficiency for EVs. In ICE cars recent improvements in efficiency have come about primarily from changes to the power plant. However, in EVs, motors are pretty much at the limit of what is physically possible. The vast majority of power in EVs is used to overcome aerodynamics, and accelerating mass. Aerodynamics are not unique to EVs and again are close to optimum. There is some scope for advancement in areas unique to EVs such as regenerative braking and cabin-heating (I see Tesla are now using heat pumps) but I can't see this being more than a few percent in overall efficiency.

A potential future area of improvement will be driverless cars, where the driving characteristics can be precisely controlled to optimise efficiency. It could also lend itself to re-inventing the design of the car once you don't need a driver (e.g. something longer, thinner and lower, possibly on two wheels) which could be significantly more aerodynamic. But that is decades away.

thevilla

Lighter or fewer batteries = fewer lighter batteries required.  That's where optimisation of EVs will be achieved.