表达 “recharge one’s batteries” 通常用来表示 “某人非常疲劳，需要通过放松来恢复体力、养精蓄锐”。这个表达将身体的精力值比作 “battery（电池）” 的电量，而补充精力就相当于 “recharge（充电）”。

例句
I need to go on holiday so that I can recharge my batteries! I’m really tired from a long month at work.
我需要去度假，这样才能好好充电！我工作忙了一整月，真的很累。

She decided to go on a cruise to recharge her batteries.
她决定乘船旅行，养精蓄锐。

Bob felt really ill. He hadn’t taken time off to recharge his batteries for a long time.
鲍勃那时身体很不舒服。他已经很长时间没有请假休整一下了。