How to prolong lithium based batteries

Original Article ↗ Hacker News Discussion ↗

Charging range, cycles, and state-of-charge buffers

  • Many commenters aim to keep lithium batteries in a mid-range (e.g., 30–80% or 40–60%) and avoid deep cycles like 100–5%, which are said to be more damaging.
  • Some laptops/phones and EVs expose charge limits (e.g., 60–80%) that users exploit to keep maximum charge below 100%.
  • There is discussion that devices often hide real capacity: some BMSs reportedly map “100%” to less than true full charge and “0%” to above absolute empty, but the buffer size varies and is device-specific.
  • One claim: degradation tends to floor around ~80% capacity regardless; careful habits just delay reaching that point.

Fast vs slow charging and current

  • Many want explicit “slow charge” / “charge to X%” controls per session.
  • Workarounds include using low-power chargers, wireless chargers, current-limiting adapters, and scripts or root-only tools to cap current.
  • Consensus: higher charge rates and high “C” (e.g., very fast phone chargers) accelerate wear; lower current and avoiding the last 10–20% are seen as protective.

Temperature effects

  • Strong agreement that heat is harmful; suggestions include good airflow, avoiding hot cars, and using vents or active cooling mounts.
  • Some push back on “the colder the better,” arguing batteries should stay near their rated temperature; extreme cold plus charging can cause damage (e.g., lithium plating).
  • For LFP, tests cited: modest extra degradation at 35°C vs 25°C but still very long lifetimes.

Chemistry- and application-specific notes (LFP, EVs)

  • LFP: flatter voltage curve makes SOC estimation harder; many BMSs rely on coulomb counting plus periodic 100% charges for balancing.
  • Some claim LFP tolerates high SOC well and is “hard to kill,” with guidance to charge to whatever is convenient and not fear full charges.
  • Off-grid / seasonal use: LFP is viewed as fine stored cold and idle, with BMS quiescent draw considered negligible.
  • EVs: modern packs generally use active cooling; advice is to avoid charging or heavy acceleration when the pack is very hot. Older designs without cooling (e.g., early compact EVs) were noted as problematic.

Software, tools, and trade-offs

  • Numerous tools (OS settings, root apps, desktop utilities, smart plugs) are used to limit charge %, current, or temperature.
  • Some users meticulously manage charge windows; others ignore all this and simply replace batteries every few years, arguing the hassle may not be worth marginal gains.