also: モバイルバッテリ
portable battery charger; power bank; external battery
A portable rechargeable battery used to charge mobile devices like smartphones and tablets. Common everyday term.
from English mobile battery
I always take a power bank with me when I travel.
My smartphone was about to die, so I used my portable charger.
Shortened variant without the long vowel marker; often seen in product names or casual writing.
Explicitly separated form with interpunct; rarely used in running text but may appear in dictionaries or technical contexts.
Explicitly separated shortened form; very rare in practice.
Loanword from English 'mobile battery', referring to a portable power source for electronic devices.