Yes, the most sophisticated components do have electronics to function (microprocessors, sensors) so they need to have a battery. This battery gets charged every 2-3 days depending on its use, just like your mobile phone.
The components that require charging are some types of ankles and some knees.
By having all the electronic components, they can do fantastic things and think ‘for themselves’ when going up or down a slope, or when you are sitting down. They are great!