max out

mainly US informal
to do or have as much as possible of something, or too much of something:
The air conditioner was maxed out, but it still felt hot in the car.

ビジネス英語
informal
to spend or use the largest amount that is allowed, so you cannot spend or use any more:
When they max out their credit cards, they go to money lenders.
The general rule is to max out your hardware - fill every slot with the biggest memory card it will accept.

to reach the highest level possible or allowed:
The port's capacity is due to max out in around five years.
max out at sth DSL modems maxed out at a data speed of 1 to 1.5 Mbps.
(Cambridge ビジネス英語辞典 からの max out の定義 © Cambridge University Press)

- Cambridge Dictionary