Featured Lithium Battery developments "Reuters exclusive"

Yeah, it is. They traded off power for energy. If they went the other way they could, for example, charge the entire pack from 0% to 95% in 20 minutes.

There's almost always a trade off.

 

My interest is reaching my Mom's home or hometown which is a function of the energy density. I need to travel ~750 miles in ~14 hours. You of course are welcome to beat me at the the drag strip but that has no use when I'm trying to reach home.

Bob Wilson

 

Hence, why I said, "Tesla (rightly) uses low-power cells to get the most energy because energy is the problem with EVs, not power, even with low-power cells."

I'll "beat" you by not having to stop to charge for more than 2 minutes on a 750 mile trip.

 

they finally added a fan to the 2cv

 

The long range pack on the model 3 can charge 150 miles in 15 minutes on the v3 chargers tesla is rolling out. Sure you could charge a battery like the project one faster but it would weigh a lot more to provide that range let alone the rate at a L2 charger would be slower as these slow down as they get close to fully charged. Not really a trade off. You could increase the battery size to charge 300 miles in 15 minutes (a 620 mile battery like being tested in the cyber truck) but then you need higher more powerful charging network. No it isn't a trade off of power verses energy when it comes to these things. If you want to charge miles faster you want a high energy battery.

 

Only if the temperature and starting state-of-charge are exactly right. If not, it's a lot slower and they slow down a heck of a lot after that anyway.

These higher-power batteries don't really slow down until they are above 95%.

No, it's still a trade-off.

Think about it. I could add 30% to the mass of the battery, itself about 25% of the mass of the car, to effectively quadruple the charging rate. That'll reduce efficiency by 5%. 400% faster charging, 5% more energy needed. The math isn't difficult.

 

Sounds like a business opportunity . . . someday. Perhaps start with electric hand tools and lawn equipment?

Bob Wilson

 

As I said, it's a bad idea and Tesla chose the right path. But it was still a trade-off.

 

The car conditions the battery on the way to the charger. The fast charge rate is from 5%-60% after that it slows down, I'm not sure how you would charge faster (miles/hour) on a lower energy battery. Remember you can do that full 95% (100%-5%) on the first leg of a trip.

Can you point to one of these that can charge 150 miles to 95% in 15 minutes and what that charger is?

Show me the battery and trade off. The current ones I know of are heavier and more expensive to charge the same range in 15 minutes.

You still need to build those chargers. Can you give me the specs of said battery and what it costs. I did give you the example of the mercedes project one that wanted a low weight battery that could add power to a sports car. It can charge really fast but ... it only can power 25 miles.

 

I've watched many videos of people trying to charge that way, and it's definitely hit-and-miss.

I can point to a battery type that can handle that. No one uses them in cars because they have like 30% less energy density.

Which is exactly what I said in the first place and exactly why this is a trade off.

 

Well good an example. 80 kwh tesla pack 480 kg, with Maxwell tech it will probably drop to 430 kg and charge faster. Higher power pack - 80 kwh 480 / 70% = 686 kg but then you probably need 5% bigger because of extra weight so 84 kwh @ 720 kg for the pack making the car 12% heavier, and needing electronics and motors to supply about 25% more power for similar acceleration. All that costs more money and hurts handling. I guess you could build 500 kw chargers to charge this twice as fast (37 minutes from 10%-90% on the model 3 long range on a 250 kw charger according to motortrend). Since most of us charge most trips over night at home, I'm not seeing how more money and more weight for faster charging on chargers that you could build but don't exist now makes sense. For the same weight you could put a pack with 50% more energy and power, that you could charge 25% faster for the same distance, and it likely would be less expensive.

 

Nice compare and contrast of different LiON battery chemistries:
Types of Lithium-ion Batteries – Battery University

Bob Wilson

 

I would just add some LiFPO4 data - lithium iron nano phosphate is used in the very expensive F1 batteries. A123 (an american small company that went bankrupt and is now owned by the Chinese company Wanxiang) made the first F1 batteries using MIT patents with a power density of 20,000 watts/kg in 2009. I'm sure they have improved. The chinese government has poured a lot of money into the R&D in the last decade. The CATL/Tesla LiFPO4 is probably using a much less expensive and less power dense formula and has probably pushed energy density to 200 wh/kg, versus tesla's current 250 wh/kg with panasonic's NCA. The NCA cells in the long range pack weigh 322 kg out of the 480 kg pack, the CATL's will probably weigh around 403 kg (81 kg more) but because of the packaging in the pack the whole pack would probably be less than 50 kg (110 lbs) more. This may only be used in the standard plus and smaller packs. At the same time NCA with tesla's dry electrode tech is probably at 300 wh/kg right now in the lab shaving cell weight to 268 kg. With direct to module manufacturing that will shave more than 50 kg off a long range 80.5 kwh pack.