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Comment by heymijo | Hacker News Reader

Double the capacity, no exotic materials, same size as a regular battery pack and not much more weight.

Tested in cold Michigan weather instead of more idyllic conditions adds credibility.

This doesn't sound like vaporware. I wonder what barriers there might be to scaling this up to mass production.

We'll need to know how quickly it can be charged, how many charge cycles it takes, how it drains when not in use, etc etc, but you are right, it's a promising start, one to watch to see where it ends up.

Past a certain capacity, I wonder where the need for rapid charging begins to decrease. It might be an interesting trade off.

1C, which isn't fast charging, is already 200kW with this battery. So yeah, if you can make a battery with a massive capacity, but it can't fast charge, that could be a great tradeoff.

In the article they state they charged it at 1C, which is 1 hour from 0% to fully charged (200kw for a 200kwh battery). Who knows what the final numbers will be, but very promising if true.

Yeah, but maybe that was one of the 100 the battery can take before it's at 70% life. There are just so many sliders with a battery, and they all effect each other. Getting them all up at once is the grail.

Nice analogy, the "sliders."

1C is usually not 1hr from empty to fully charged, because of CC-CV charging. Most Li based chemistries charge at 1C until a certain threshold (when the needed voltage for 1C charging reaches a maximum predetermined level, usually the target max cell level, e.g. 4.2V). After that, you charge at constant voltage until you reach full charge. If the battery is significantly oversized, i.e. it treats 85% charge as 100% for the user, then 1C might be possible from 0 to 100%, but usually it's not.

Just assume it takes twice as long to charge, since the circuit will be a factor if you double the capacity. Your 208 40amp circuit can only deliver so much power, and even dc fast chargers can only go as fast as they can consume power from there circuits.

LFP charges pretty well since it is so much safer.

The real mystery is the "non-LFP" battery cells they used.

Exactly. It sounds good, but can it do this at least two or three times a month for 10 years?

>Double the capacity

How can it be double the capacity when the wikipedia article for LFP battery says it has "lower than that of other common lithium ion battery types such as Nickel Manganese Cobalt (NMC) and Nickel Cobalt Aluminum (NCA)"? What type of battery does the stock tesla battery pack use?

The general rule of thumb for such fundamental breakthroughs is that unfortunately for 99% of the really huge ones we'll only know they're revolutionary when the inventors get Nobel prizes 5-15 years after the fact.

99% of these articles are trash that never gets talked about again after 6 months.

Maybe this one isn't, I can't tell. Time will tell, though.

Maybe they use the space for effectively that packing all those 18650 into the pack.

The article says the battery is split, with an LFP traction battery and another undefined battery to make up the "range extender" - presumably the bulk of the capacity. So I suspect they've got some sort of novel high capacity low discharge battery which keeps the regular LFP battery topped up, which then drives the car.

Personally I wonder if it's going to lower prices. It takes a long time to use enough gas to make up the $10K difference between a cheap gas sedan and a cheap electric sedan.

So far, so good -- let's see what the pricing will be like :)

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