the.com/power bank
A brick you charge so your phone can ignore you somewhere else.
means A portable battery pack you charge up in advance so you can recharge phones or other devices when there's no outlet around.
from Straightforward compound coinage, not an old word at all: 'power' for the stored electrical charge, and 'bank' in its sense of a reserve or stockpile (as in blood bank or piggy bank) rather than a riverbank. It emerged alongside the smartphone boom, once batteries got small and energy-dense enough (largely thanks to lithium-ion tech) to make a pocketable backup battery worth carrying — the name simply describes the function: a bank you withdraw power from.
- capacity lie
- rated mAh never equals usable output, blame voltage conversion
- airport rule
- must fly in carry-on, banned from checked luggage
- self-drain
- loses charge just sitting in your bag unused
- origin
- exploded in popularity alongside smartphones killing swappable batteries