Professional's Favourite (MotorPRO) 17.5Mcp rechargeable spotlight
D.I.Y. - H4 HID conversion
Recently I purchased a MotorPro 17.5MCP rechargeable spotlight from a local retail store 'Kmart' for about $45.00 AUD (you can find additional details in the 'good deals' forum) and was firstly blown away by it's performance and sheer size (it's a monster sized spotlight) but quite disappointed by less than adequate run times, I was looking for a solution...
Along came CPF's KrisP with an offer to share a (relatively) cheap Chinese 4300K HID kit purchased from eBay, eventually we agreed on a 55w unit
Unfortunately the ballast complete with it's protruding connectors would not fit the available space in the spotlight's casing, thus some modding will be necessary
Relevant Dimensional Specifications:
Battery compartment (W) 68mm x (H) 98mm x (D) 150mm
Ballast casing (W) 80mm x (H) 90mm x (D) 30mm
Reflector (W) 123mm x (D) 90mm
Total mass (modified) 5.0kg
Step 1 preparing the ballast
The excess aluminium was cut off the ballast housing (using a hacksaw) and filed down to remove any rough edging, the socket pins were also cut back flush with the ballast casing.
The bulb-to-ballast loom had it's connector removed and wires stripped back & soldered to the 2 shortened ballast output pins (ensuring correct polarity).
Next heat shrink was applied to protect & re-enforce the soldered feed connection.
I carefully cut & peeled the metal crimped cover off (the high voltage line) to gain access to the aluminium collar underneath, this in turn was slowly trimmed away with a hacksaw making sure as to NOT pierce the high voltage line (which would've effectively ruined the ballast), the modified ballast unit was then simply affixed with that wonderful double sided foam tape primarily used to hold external automotive protective door trim/strips in place.
Step 2 - building a H4 mounting collar/focus shim
I made 3 attempts to create a suitable shim/collar ending up with the one you see below, with a bit of trick grinding/tool work I was able to retain the original wire clip retention concept for the HID globe, the added clearance equaled 11.38mm (using my digital caliper)
Specifically I took a piece of 50mm (inner diameter) steel tubing in this case from an old bed frame and cut a 23mm collar from it, making 6 vertical cuts approximately 11.62mm in depth (positioned in relation to the tongues of the globe base) I folded them down to support the globe base (because 50mm tubing is slightly too big), next with the grinder (and cutting wheel) I made 2 horizontal slots opening one up for the retention clip (see diagram below)
The H4 HID globe was secured using the original bulb retainer spring however due to differing bulb characteristics the HID bulb sits too far into the reflector assembly causing an over focus effect complete with nasty artifacts (still nice and bright though!)
I compromised between a beam without artifacts & a tight focus point, personally I prefer the pencil beam characteristic & thus was it my goal when setting up the HID globe, below is a beam shot (comparison) using exactly the same set of parameters (note the slight hint of artifact on the unfocused HID), sorry I don't have a tripod for my camera
Well that's pretty much it for this project for the moment it didn't turn out too bad IMHO, performance is good for an all up cost of around $100.00 AUD though I wouldn't mind using the original low beam feature somehow but that's for another day... perhaps an LED auxiliary lamp OR built in voltmeter? any questions? suggestions feel free to post in this thread
EDIT - I finally purchased a decent digital camera so here's the long overdue 'true beam shot' this image is of a local derelict farm house located 300 meters (328 yards) from the roadway
Shutter speed of 2.5sec - Canon Powershot A590IS