*Please consider this a work in progress until this notice is removed*
Beginners Guide to Hotwire Incandescents
Post 01 - This Guide
Post 02 - Recipes and Ratings
Post 18 - Color Temperature Profiles
Post ?? - Photographic Bulb Profiles
Post ?? - Case Study: Mag vs SF
Post ?? - Beam Shots
Incans represent the original electric light source, starting with the first electric bulb and the first flashlight (so named in the US because blinking/flashing was employed to extend battery life). Hotwire incans are the greatest expression of this original vision and are to be differentiated from other leading flashlight technologies, particularly HID and LED. For purposes here, hotwire means greater than normal light and heat.
For most of the last decade, hotwire incans have pushed the limits of existing configurations, requiring increasing levels of skill, daring, and money. These requirements limited the appeal and popularity of incan flashlight creation and adoption. But we are seeing innovations that combine to create what I consider to be a new golden age of incans.
Innovation #1 - Simple bi-pin adaptors
Beyond generic bulbs are xenon bulbs. Beyond xenon bulbs are halogen bulbs. Beyond socketed (potted) halogen bulbs are bi-pin halogen bulbs. Designed for scientific instruments, the most popular bi-pins are out of place in most as-is flashlights. But thanks to FiveMega, bi-pins are right at home in two of the most popular host form factors, Mag C (as designated by battery size) and SureFire C (as designated by thread size).
Innovation #2 - Fast discharge batteries
The key to hotwires is voltage, double and triple what was considered normal 10-20 years ago. First there were multi cell adapters, holding multiple standard normal cells in magazines of various configurations (6AA->2D, 9AA->3D, 12AA->4D). Then, lithium ion cells came on the scene, increasing densities for voltage and energy. But such chemistries require expensive and often ill fitting protection circuitry to enable safe use. One of these protections is against over discharge, by limiting current flow, in direct contradiction to the high drain needs of incan bulbs (ie double-press to start).
But thanks to AW, there are now IMR cells (LiMN - Lithium Manganese). Standard battery sizes, standard cost, high energy density, and high discharge rates (what incan bulbs crave most). And they fit right into popular flashlight bodies (hosts), without the need for expensive and troublesome adaptors.
Step 1 - Host
The first step in building this new kind of incan is choosing a host. This can be based on size/runtime requirements or simply by what you have sitting in your parts drawer (or on your mantle). Mag hosts cost less, but don’t come equipped with high temperature reflectors or lenses/windows. At this point (more to be added), there are 2 basic host options (small/big) and 2 voltage options (2 cell or 3 cell), but you are really only limited by budget and [FMs] imagination.
Surefire “C” or compatible (small size, low runtime)
2-cell - this can be a stock 6P, C2, Z2, etc (65 lumens @ 6.0v)
3-cell - this can be a stock 9P, C3, Z3, etc (105 lumens @ 9.0v)
2-cell - this can be a stock 9P, C3, Z3, etc with a dummy CR123A
3-cell - this can be a stock 6P, C2, Z2, etc with a cell extender (A19 etc)
Maglite (large size, high runtime)
2-cell - this can be a stock Mag 2C (36.5 lumens @ 3.0v)
3-cell - this can be a stock Mag 3C (76.8 lumens @ 4.5v)
Step 2 - Batteries & Chargers
Depending on how step 1 goes...
Stock 6P = 2 AW IMR16340’s
Stock 9P = 2 AW IMR17500’s (when available)
Stock 9P = 3 AW IMR16340’s
Stock Mag2C = 2 AW IMR26500's (see note 4)
Stock Mag3C = 3 AW IMR26500's (see note 4)
Modified Mag2D = 3 AW IMR26500's
Modified Mag2C = 3 AW IMR16340’s (thanks Niteowl!)
Available directly and through dealers
C Cell Charger
LITEmania Charger for C/IMR26500
Basic Non C Chargers
Ultrafire WF-138 Charger for RCR123A/IMR16340
Ultrafire WF-139 Charger for 17500/17670/18500/18650
Also available directly and through dealers
Advanced Non C Charger
Pila IBC for RCR123A/IMR16340/17500/17670/18500/18650
Step 3 - Bulb Sockets et al
FiveMega G4 D26 SUNLIGHT for $urefire (includes high temp MOP reflector)
FiveMega G4 bi-pin socket for M*g (lens & reflector extra, see step 5)
Unlike the SF socket, this design currently lacks a retaining screw
Its necessary to gently bend the bulb pins so they stay in the socket
Pins bent in this way will be harder to insert into SF sockets
Step 4 - Bulbs
There are two types of incan bulbs, potted and bi-pin. Potted are the standard style that has been popular for a century, drop the half metal module into the socket and screw down the retaining collar. Bi-pins, as their name implies, are almost bare glass with two pins protruding from the bottom. For the purposes of this guide, bi-pin bulbs require one of the adapters from Step 3, potted bulbs (Mag only) do not. This is not a comprehensive list of bulbs, merely those that work best with these hosts & cells.
To little voltage and bulbs produce inefficient yellow light. To much voltage and you destroy the bulb. The ideal is to the overdrive it enough to get brighter/whiter output without pushing it to far. Easy to do with regulation (step 5), but more trial and error without it. See post 2 for tested non-regulated configurations. At 3.7 volts per cell, 2 cell setups are 7.4 volts and 3 cell setups are 11.1 volts. More amps (a) equals more lumens (L) but it also means more heat and less runtime.
2 cell bulbs - 7.4v (8.4 volts fresh off charger)Maglite only (bi-pin socket not needed)
Potted Pelican 3853L: 290L @ 7.2v - 1.50a | LuxRating: 360L at 8.0v - 1.60a (see note 7)
Potted Pelican 3853H: 600L @ 7.2v - 3.40a | LuxRating: 928L at 8.4v - 3.70a (see note 7)
2 cell bulbs - 7.4v (8.4 volts fresh off charger)Maglite & SureFire
Bi-Pin WA 01274: 553L @ 7.2v - 2.77a | LuxRating: 864L at 8.4v - 3.10a
Bi-Pin WA 01111: 465L @ 6.0v - 3.35a | LuxRating: 874L at 7.4v - 3.80a
3 cell bulbs - 11.1v (12.6 volts fresh off charger)
Bi-Pin WA 01166: 704L @ 11.6 - 1.97a | LuxRating: 870L at 12.6v - 2.06a
Bi-Pin WA 01331: 534L @ 9.6v - 1.93a | LuxRating: 700L at 11.1v - 2.15a
Bi-Pin WA 01185: 817L @ 9.6v - 3.15a | LuxRating: 1401L at 11.2v - 3.40a
[Information courtesy of LuxLuthor and Litho123 (purchase link)]
Step 5 - Options & Extras
Mag reflectors (C & D)
Mag Lenses (C & D)
Mag Heatsinks (C only)
Regulation (advanced voltage and output control)
AW Softstart / 3 level Incan Driver Switch for SureFire 'C'
AW Softstart / 3 level Incan Driver Switch for Maglite C
AW Softstart / 3 level Incan Driver Switch for Maglite D
Step 6 - Adjust Focus (optional)
Beam quality/behavior is determined by the relationship between the bulb and the reflector. For example, the larger the reflector, relative to the bulb size, the more control you will have and the more light can be projected (think spot light). The other key factor is the position of the filament (the coil inside the bulb) relative to the bottom of the reflector.
For optimum bulb placement in a SF configuration, begin by positioning the filament just above the bottom opening in the reflector, then fine tune from there. This is controlled in the FM socket by unlocking, then turning the brass bulb base inside the aluminum housing. When ready, point it at a wall or ceiling. If there is a dark spot in the center (aka donut), the bulb is probably positioned to high.
Maglite (with cam)
Unlike the SF configuration which is set during assembly, Mags are adjusted during use. If you have a cam (an angle cut tube extending from the bottom of the cone) equipped reflector, loosen/tighten the head of the light in half turns to get the desired focus. If you would like to control the focus starting-point when the head is fully tightened, see my Mag calibration guide.
Maglite (no cam)
If your reflector lacks a cam (or its removed), adjustment is similar to having a cam, just slower and more precise. It can take several full revolutions to equal a half twist with a cam. The configurations shown here work both with and without a cam, so the choice is yours: fast or slow focus.
Step 7 - Enjoy!
SureFire: LumensFactory IMR Ready Drop-Ins (more info)
MagCharger: to upgrade a MagCharger, ignore most of this guide and add a Mica shield (when available) and 1160 bulbs from Litho123. 5761 bulbs also work but reliable operation requires replacing the plastic socket with a ceramic socket (also from FM) and enlarged reflector opening.
rikvee's Popular bulbs current draw
LuxLuthor's destructive incan bulb tests
LuxLuthor's most powerful Maglite mods list
LuxLuthor's Li-Ion categories
mdocod's rechargeable battery guide
mdocod's Lithium-Ion > incandescent guide & compatability/comparison chart
mdocod's tests on the WF-139
mdocod's reflector efficiency discussion
- These configurations are capable of producing intense amounts of heat. Keep out of reach of children. Do not leave any light unattended while running. Take care when storing your completed lights so they will not activate accidently.
- While utilizing "safe chemistries," IMR cells are capable of releasing enormous energy. Read AWs warning and cautions before use and familiarize yourself with standard handling protocols.
- IMR cells will last longer if they are not deeply discharged. For maximum life, turn off your light as soon as it starts to dim and recharge the batteries as soon as possible.
- IMR 26500 cells are slightly to wide to fit into standard Mag C's. You can either enlarge your Mag's opening (link) or reduce the thickness of your cells (link)
- Get yourself some high purity rubbing alcohol (90+). After a bulb is handled and before it is turned on, wipe it down. This helps prevent poof.
- If you want the ability to swap bulbs in the field with SF configurations, pre-load (and test) two complete FM sockets and have the extra ready. Change out dead bulbs after you get back.
- Standard 6 volt ROP bulbs (model 3854), while happy in most dual Lithium-Ion configurations, cannot handle the higher voltage produced by the IMR26500 cells presented in this guide. For these cells, 7.2 volt ROP bulbs (model 3853) are recommended, available at Battery Station.