Then I'd take a charger with me...
And do what with it?
charge it at the temple of Zeus, presumably
I'd charge at the enemy with it...
Would we even have a signal to use the phone?
Clearly never charged a battery with just wire and contact leads....also battery can be made from lemons and base metals.
Pics of Genghis kahn..coming up.
Take a solar panel with you and a charging cable
Slow down doctor Brown
Time travel forward?