The lens and reflector were harvested at the self-service junkyard from a BMW head-lamp. The 35W HID bulb and balast are from DDM. In the original configuration a stamped steel part was used to hold the lens in front of the reflector. That part incorporated a baffle in the focal plane of the lens to block the “top” half of the beam for on-road use- to keep from blinding oncoming drivers. I elected to throw out the stamped metal bracket and make a new lens holder. The reflector is captured by the ring of screws around the base of the lens holder. The lens is retained by a large cir-clip.
The cir-clip is arguably the least-functional part of the design. Warping and imprecise fit-up during welding became major issues in getting the cir-clip to seat, not helped by the fact that cir-clips that large have an extremely strong spring-force required to compress them. This is a part that I would not do the same way again.
The charging-port and AstroFlight Blinky Balancer are attached under the rear of the torch.
When the tie-rods are undone the light slides apart, with the tabs in the bottom plate and at the back of the main tube fins dropping out of the square holes in the front plate and rear plate. This reveals the inverter, sitting on the bottom plate, and the ignitor and HV connectors for the HID bulb which fit inside the main tube.
The battery pack is composed of eight DeWalt drill A123 26650 cells, grouped in two packs of four cells in series. The two packs are paralleled at the cell level using the wiring harness shown in the second photo. Balance taps and main charge and load leads are broken out from this harness. The connectors are Molex MiniFit Jr.
When the bottom plate is replaced the fit of the batteries, balast, ignitor and switch becomes clear.