full tank; filled up
Primarily used for gasoline or fuel tanks; implies the tank is completely filled.
Please fill the tank up.
full capacity; completely full
Extended use for batteries, containers, or any receptacle filled to its maximum capacity.
The car's fuel tank is now full.
Please disconnect the charger once the battery is fully charged.
This container holds 10 liters when full.
満タン describes a battery or tank that is completely full, the opposite state of 電池切れ, which means it has run out.
Standard kanji-katakana spelling; the most common written form.
All-katakana spelling, often seen in casual or emphatic contexts.
Abbreviation of 満タンク (full tank), from 満 (full) + タンク (tank). The katakana portion reflects the loanword origin.