How to quickly charge your smartphone: fast charging technologies in detail

Original Article ↗ Hacker News Discussion ↗

Wireless charging & magnetic alignment

  • Several comments note that magnetic alignment for inductive charging predates modern MagSafe-style implementations (e.g., older Nexus and Palm systems).
  • Wireless charging is praised for eliminating port wear and dust issues, but multiple commenters warn it tends to heat devices more and may accelerate battery degradation, especially without active cooling.

Desire for user control over charging behavior

  • Many participants want simple, explicit controls: e.g., default slow charge with a one-tap “fast charge this time” option, or physical toggles on chargers for slow/fast/app-controlled modes.
  • Existing features like Adaptive/Optimized Charging, fast-charge toggles, and 80% caps on Android and iOS are appreciated but often seen as:
    • Hidden too deep in settings.
    • Too coarse (only 80%/100%).
    • Lacking easy temporary overrides.
  • Some use external dongles or root-only apps to set current limits, voltage caps, temperature limits, or battery-bypass modes.

Battery longevity vs convenience

  • One camp argues most users just want the fastest possible charge and will replace phones every few years; they see micro-managing charge as overkill.
  • Another camp deliberately caps to ~60–80%, uses slow chargers, or avoids heat, reporting multi‑year good battery health.
  • There’s debate over whether constant plug-in use “cycles” the battery; one commenter with design experience explains common controllers bypass the battery when full, with minimal top-off cycling.
  • Multiple anecdotes suggest 80% limits materially slow degradation; others report little difference versus “just charge overnight.”

Standards, protocols & fragmentation

  • Commenters are frustrated that while USB‑C is standardized physically, fast‑charge protocols remain fragmented (PD, QC, proprietary schemes).
  • Many argue USB PD (especially with PPS) plus Qi should dominate to reduce incompatibility and confusion about which cable/charger combo gives fast charging.
  • Some note PD was never fully deployed on USB‑A and nonstandard protocols will linger as long as A ports/cables remain common.

Replaceable batteries & service costs

  • Several argue that user-replaceable batteries would make fast-charging worries mostly irrelevant and reduce waste; others value thinness, rigidity, and waterproofing more.
  • There’s irritation that a cell costing only a few dollars translates into much higher in-store replacement costs.

Technical accuracy & critique of the article

  • A technically minded commenter criticizes the article’s conclusion that “slow 5 W charging is best,” arguing:
    • Heat and time spent at high state-of-charge matter more than sheer wattage.
    • Fast charging up to ~80% at cool temps can be better than slow charging to 100% in warmth.
  • Battery University is recommended within the thread as a more reliable educational resource.