BGE and the State of Maryland have partnered to allow the public to charge electric vehicles at State Center. Eight spaces are available with Level 2 (240V) chargers.
Payment is usually via a smartphone app. According to the BGE website, $5 will add 116 miles to the range of an average car in 231 minutes. That is based on a cost per KWH of $0.18. Spaces cannot be reserved, but early this month there was no problem finding a space.
Lot C is accessed from 1030 Mason St., west of the armory and north of the medical tent: very convenient to park an electric car and walk back to Bolton Hill for half a day. More information is available here, along with a map showing 850 charger locations.