Why do modern telephone rechargers need to change AC electricity to DC electricity?

Question

Why do modern telephone rechargers need to change AC electricity to DC electricity?

Answer 1

Because all batteries are DC. An AC "battery" would require either moving parts (ie it would be a generator), or it would bee very large & heavy (like a UPS)...

Answer 2

Most of the electronic goods including batteries come as DC which is easier to work with, but to transport electricity AC is better as the loss is negligible.

Answer 3

Batteries are by their very nature DC or direct current, an AC source reverses polarity frequently, negating any charging effect and possibly ruining the battery as well. Most inexpensive chargers provide a chopped DC current  that is displayed like this example.    =-=-=-=-=-=-=-=-=-The lower conductor is usually the ground circuit . the chopped signal on top is usu. positive, this will charge a battery as well as a steady DC current. Just slightly slower.

Answer 4

Batteries are DC devices.  AC doesn't recharge 'em