Bonjour Paul,

Thank you for your comment! We've listened to the audio recording and we can't hear "charger". 

When doing a listening exercise, you have to use external elements on top of your grammar skills, especially, if you think you are hearing a word that does not make much sense. So it's important to keep an eye out for the context, the topic and use one's common sense.

Link to user's answer: audio issue

I hope this is helpful.

Bonne journée !