BYD begins testing solid-state EV batteries in the Seal

Original Article ↗ Hacker News Discussion ↗

Charging speeds, power levels, and safety

  • Commenters note the “12 minutes for 932 miles” implies close to 1 MW charging (around 1500V, 600A).
  • Some see this as only an incremental extension of current DC fast charging; others worry about risk from water‑cooled, very high‑current cables.
  • Several argue that, properly engineered, 1500V DC isn’t fundamentally more dangerous than today’s 480V fast chargers, as both are lethal and require heavy interlocks and monitoring.

Use cases beyond cars (home and grid storage)

  • Original question: could this tech be more impactful for power walls / home storage than cars?
  • Replies say the charging tech itself isn’t revolutionary, but better energy density and cycle life would be very attractive for stationary storage.
  • Some mention that residential batteries in some regions already cost less than a high‑end smartphone, implying large future potential if energy density and cost improve further.

Why cars before phones?

  • One camp: EVs gain more value from higher energy density and fast charging than phones, so scarce early production goes to vehicles where consumers pay more for the benefit.
  • Counter‑argument: the same material could produce huge numbers of higher‑margin phone batteries; it’s unclear pure economics favor cars.
  • Additional points:
    • Phone batteries already use Li‑polymer “solid” formats and must handle highly bursty loads.
    • Scaling some solid‑state chemistries down to thin, safe, high‑C‑rate phone cells is technically harder and costlier.
    • Cars tolerate larger, heavier cells and have smoother discharge profiles.

Range needs, pack size, and external batteries

  • Many say 1000+ mile range is excessive; 250–400 miles plus very fast charging is the “sweet spot.”
  • Others note battery degradation near high state of charge; big packs used at 30–80% can improve longevity but add weight and cost.
  • Ideas like towable or trunk “range extender” battery packs are debated: conceptually attractive but challenged on weight, cost, aerodynamics, and rental economics.

Energy density and solid‑state confusion

  • Some had thought solid‑state meant lower density; others point out higher specific energy has always been a key motivation.
  • Clarifications: 400 Wh/kg is roughly double mainstream Li‑ion EV packs and particularly valuable for drones and other weight‑sensitive platforms.
  • Distinctions raised between solid, semi‑solid (e.g., silicon‑carbon), LFP, and Li‑polymer chemistries, with some confusion and correction.

Cold‑weather behavior and safety

  • Long sub‑zero climates (Montana, Canada, Nordic countries) generate heated debate.
  • Pro‑EV experiences: modern EVs work fine with ~20–30% winter range loss, pre‑conditioning, and block‑heater‑level power; cabins heat faster than ICE.
  • Skeptics emphasize severe cold (–30°C and below) where packs can’t deliver rated energy, risk of being stranded if you lack margin to warm the battery, and long rural distances with no backup.
  • Safety tradeoffs discussed: EVs avoid carbon‑monoxide deaths from blocked tailpipes but can still leave drivers short on range in extreme conditions.

US–China, tariffs, and industrial policy

  • Large subthread on whether cheap BYD‑type EVs should be allowed to “destroy” domestic auto makers versus the climate and consumer benefits of low‑cost Chinese EVs.
  • One side: blocking Chinese imports is protectionist, slows decarbonization, and leaves Americans paying more for worse cars; competition is necessary to force innovation.
  • Other side: allowing heavily subsidized Chinese EVs can wipe out US auto and adjacent manufacturing, increasing strategic dependence and hurting national security; some level of protection is seen as necessary.
  • Multiple comments argue both the US and China subsidize EVs; the debate is over scale, structure, and whether subsidies target production vs. consumption.

Charging infrastructure and real‑world usability

  • Some contend US charging access is already good enough for most households (single‑family homes, urban and suburban chargers), with public stations more than doubling since 2020.
  • Others highlight pain points: unreliable or crowded chargers, apartment dwellers without home charging, and much longer “refuel” times versus gasoline.
  • Long‑distance driving:
    • Pro‑EV drivers report cross‑country trips are practical, with 10–30 minute fast‑charge stops every few hours and overnight charging at hotels.
    • Critics emphasize 500–1000‑mile days with minimal stops, where EV charging time materially lengthens travel, especially for outlier use cases.

Climate, politics, and “resistance to electrification”

  • Several comments frame US skepticism toward EVs and Chinese greentech as a major self‑inflicted wound on both climate and industrial competitiveness.
  • Others say a significant share of Americans either don’t prioritize climate change or see EVs as culturally/politically hostile, complicating policy.
  • There’s concern that the US is falling structurally behind China in manufacturing capability (including batteries and high‑precision components), and that reversing this “brain/skill drain” will take generations.

Commercial and military applications

  • Beyond personal cars, commenters expect high‑density solid‑state packs to be especially important for:
    • Robo‑taxis, delivery fleets, buses, and trucks (lower downtime, fewer chargers).
    • Agricultural and construction machinery.
    • Medium‑size UAVs and drones, where going from ~255 Wh/kg to 400 Wh/kg is a step‑change in endurance and payload.

Skepticism and later correction

  • Some express outright doubt (“I’ll believe it when I see it”), given many prior “breakthrough” battery claims that didn’t scale.
  • A final note in the thread states that BYD later denied this specific news, casting uncertainty on the reported test results and timelines.