1. Touch the white button at the top of the farebox to begin adding value to your CharlieCard.
2. Tap your CharlieCard to the black card target and follow the directions.
3. Insert money—fareboxes accept cash, coins and even old T-tokens—and press the white button again to 'accept' the transaction.
4. Tap your CharlieCard again, a second time, to register the value you just added and you're done.