The "BR-800TYPE" paralyzer, a stun gun, is a personal defense weapon of Chinese provenience. Like the Type 618, it is fairly inexpensive (low 100s CZK), fairly easy to buy.
The device contains a stun gun with two prods at the front, which makes a nice ~10 mm long LOUD spark, and a small white LED based torch. The control consists of a switch and a pushbutton; the switch connects the power to the pushbutton and status and flashlight LEDs, the button control the high voltage generator.
So, let's see what's inside.
The core of the unit is a sealed high voltage power source. This part is potentially reusable in other sorts of projects. More investigation will be done in the future.
The power for the unit is provided by nickel-hydride (maybe nickel-cadmium?) cell with 4.8V/250 mAh. Pretty low capacity. The cell is tapped at 3.6V, to provide lower-voltage power for the LEDs.
The charging circuitry leaves much to be desired. The stepdown converter from mains 230V AC is using a capacitor and is galvanically connected with the mains, leaving the unit potentially dangerous when plugged in. The insulation between the diode bridge and the battery pack was found to be enhanced with a folded piece of a special material, appearing to be a torn-off strip of a playing card, a two of clubs; given that in cartomancy the spades signify "inner wisdom, industriousness and creative enthusiasm", the choice is suitable for such improvised solution.
The charging assembly should be modified; the mains connector may be replaced with a connector for attaching an external NiMH charger, working around the inherent design safety problem.
Outside case, top
Outside case, corner view
Outside case, charger port
Inside, with special insulation
Inside detail, charger circuit