Sony BC-L50
The BC-L50 battery charger is capable of simultaneous, continuous charging of two battery pack simply, simply detach fully charged one and replace it with discharged one.
Diagnostics functions; all connected battery packs are checked for abnormalities. An indicator will flash alternately in red and green is a battery pack cannot be charged normally. Charge progress indicator lights will flash orange when the battery pack is less than 80%, solid orange light at 80% or greater and light green when battery pack is fully charged.