This is an external power box for a Hasselblad EL or EL/M that allows for running the camera on external batteries.
This version uses 18650 type lithium batteries. It has space for three batteries but the camera will run perfectly fine on only two.
The front panel is separate so that you can add any removable cable or a fixed cable going to your camera. The shutter release pass through is a panel mount din connector compatible with the Hasselblad electronic shutter release cable. There is also space and an 8mm hole already in place for using a barrel jack with an AC adapter supplying the 6 volts needed for the camera.
Non-printed parts needed;
Battery terminals for 18650
Wire for making internal connections
Cable for connecting to the camera (either 5-pin 240 degree din or two pin accessory plug)
Panel mount din connector (for shutter passthrough)
Panel mount barrel jack for external power supply such as AC adapter
Wiring for din connector;
Pin 1: +6 volts and side 1 one momentary switch for electronic shutter release
Pin 2: Not connected
Pin 3: side 2 of momentary switch for shutter release
Pin 4: Not connected
Pin 5: GND