{
  "id": 19180658,
  "title": "Why EV fast charging slows down after 80 percent",
  "url": "https://urgent.news/2026/11/09/why-ev-fast-charging-slows-down-after-80-percent",
  "topic": "tech",
  "section": "Tech",
  "published": "2026-11-09T16:45:00.000Z",
  "source": {
    "name": "Engadget",
    "slug": "engadget",
    "url": "https://www.engadget.com/2307731/why-ev-fast-charging-slows-after-80-percent/"
  },
  "original_language": "en",
  "account": "Tesla's latest Model S can add up to 200 miles in 15 minutes at a Supercharger station, but charging speed doesn't stay fast. Ads and spec sheets often describe charging speed only as 10 to 80 percent or 0 to 80 percent, rarely mentioning the final stretch after 80 percent. The reason for this slowdown lies within the battery itself.\n\nEVs can be charged through regular wall sockets, home or public charging stations, and fast-charge stations. They all work by pushing electrons toward the battery, where lithium ions move from the cathode to the anode. When the car drives, those ions travel back into the cathode, supplying the electric current.\n\nCharging speed varies depending on the power delivered. A wall socket provides a trickle, while a home or public charging station offers several times more. Fast-charge stations typically deliver 50kW to 350kW, with newer ones going even higher. This results in faster charging due to a big cabinet that converts alternating current to direct current, which the car's onboard charger does for less powerful stations.\n\nAround 80 percent, the charging speed drops off. Picture the ions as passengers boarding a bus. A faster charger means more people enter each second, but the bus doesn't add seats. Initially, it's easy for everyone to find a seat, but as the bus fills up, passengers have to squeeze past others and wait for those ahead to move. Similarly, the battery's anode, mostly made of graphite, fills up with lithium ions, which is slow and becomes even slower once it's nearly full. The lithium ions struggle to settle, causing lithium plating – a thin layer of metallic lithium on the graphite surface.\n\nThis plating is partially irreversible, causing the battery to lose needed lithium and potentially grow metallic lithium spikes that can lead to short circuits. To prevent this, the car slows the charge down on purpose, even before any damage occurs. BYD recently announced a battery that can charge up to 97 percent in nine minutes, using a more upright graphite structure, easier ion movement, and faster leaving on the other side of the battery. The slowdown still happens, but it starts later and ends sooner.",
  "summary": "EV fast charging will only take you so far - the speed slows down as you near a full charge. Turns out there's a good reason.",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}