recharge your batteries

To 'recharge your batteries' means to take a break from stressful or tiring activities in order to feel refreshed when you return to them.

After my exam I decided to have a complete break from studying to recharge my batteries before the new term started.

I spent the weekend in the country to recharge my batteries. 
英気を養うために、私は週末を田舎で過ごした。

recharge the body and soul
体と魂を再充電する

You should take this opportunity to recharge your battery.
この機会にゆっくり休むことですね。

view leisure time as a chance to recharge one's battery for work
余暇を仕事への充電の機会としてとらえる