He is using your mains electricity to recharge his car battery.

他在用你家里的电源给他的车载蓄电池充电。

youdao

Mains electricity in America is supplied as alternating current at 60 Hertz.

在美国，主要供应频率为60赫兹的交流电。

youdao

The Internet went from being something exotic to being boring utility, like mains electricity or running water - and we never really noticed.

互联网正从外来的事物变成平淡的公用设施，像如电力或自来水一样，而我们从来没有真正意识到。

youdao

In the 70s when I was away from a mains electricity supply, a 12-volt battery would keep my respirator operating for just 20 minutes.

CNN: 'I lived in an iron lung for seven years'

But it is a particularly good idea for an electric car because mains electricity can be used if the car is still plugged in, thus conserving battery power.

ECONOMIST: Vehicle telemetry

The city's police are largely untrained and corrupt, only eight of 120 stipulated judges are doing their jobs, and mains electricity and water are, for many Kandaharis, a rare treat.

ECONOMIST: Afghanistan