Before revision: Another design combined the battery with a capacitor to power a pocket calculator for up to one minute at a time
After revision: .A modification suggested by "BotherSaidPooh" of Hackaday uses a modified "phatlight" red LED with its reverse diode disconnected via laser ablation, yielding slightly more power due to closer bandgap matchAnother design combined the battery with a capacitor to power a pocket calculator for up to one minute at a time