> The Hummer’s pack will allow the top and bottom layers to be temporarily switched from a parallel to a series connection<p>Bloody brilliant. I always wondered how much copper you need to step 120v all the way up to 800v for a car like the Taycan.<p>Also, 200kwh? Where's my It's Happening gif?
>Tim Grewe, GM’s Global Electrification and Battery Systems Director, told Car and Driver that the Ultium pack does not suffer capacity loss from excessive DC fast charging, so GM will not advise users to charge the pack to less than 100 percent.<p>Translation: we can get higher spec cells now, so battery capacity will be over-rated. A "100 KWh" pack will be 120 KW+. When it says it's fully charged it's actually sitting at a nice conservative 80% SoC. You could fast charge it every day because the pack is so huge that 100 KW is a nice gentle 1C charge rate. You can push the warranty out further because you have more headroom for battery aging.<p>Presumably when the car hits three or four years old it'll set a charge threshold at 80% and start warning you about fast charging. (Or maybe not? It would be in GM's interest to let you run it into the ground like a cellphone)
This is supposedly a safer battery chemistry than lithium-ion, with better behavior in fires and punctures. Although it would be good to hear from NFPA and UL on this. It's also apparently better behaved about being fully charged and discharged than lithium-ion. These are both good characteristics to have as electric vehicles start to dominate the market.<p>Drone video of one GM battery factory under construction.[1] That's the one in Lordstown, OH. Building exterior is finished. Power substation finished. A/C cooling towers under construction. Next one is in Spring Hill, TN. GM doesn't make as much noise as Tesla about building large battery factories. They just build them.<p>[1] <a href="https://youtu.be/vbgzuy6usaE" rel="nofollow">https://youtu.be/vbgzuy6usaE</a>
Original article:<p><a href="https://www.caranddriver.com/features/a36877532/general-motors-ev-ultium-battery-electric-future/" rel="nofollow">https://www.caranddriver.com/features/a36877532/general-moto...</a>
I'm not sure that there were actually new details here? The ability to join the two packs in series for a higher voltage was well known for a while now.<p>It will be interesting to see how they manage the claim of safe charging to 100%. Most other companies are doing that by adding a large buffer. It wouldn't surprise me if that is the case with GM as well.
Wanted: an EV with the looks of the Mach-E, performance of the Kia EV6-GT, the software of Tesla, the battery of GM, safety of the LIDAR-equipped Volvo XC90, and the warranty of a Hyundai. All for less than $45,000 with a $7500 federal tax credit.
> Tim Grewe, GM’s Global Electrification and Battery Systems Director, told Car and Driver that the Ultium pack does not suffer capacity loss from excessive DC fast charging, so GM will not advise users to charge the pack to less than 100 percent.<p>I'm guessing this means just means "100%" charge is not actually 100% of the battery. Most other EVs do this by a few % (even Tesla), but they also don't recommend charging to 100%. I guess GM will limit it even further.
but will you be allowed to charge overnight or park inside?<p><a href="https://electrek.co/2021/07/14/gm-chevy-bolt-ev-owners-not-charge-overnight-park-inside-garages-fires/" rel="nofollow">https://electrek.co/2021/07/14/gm-chevy-bolt-ev-owners-not-c...</a> and this is after forced recall and two supposed "software fixes"