Newbie Incandescent Mod Questions

I'd like to try my hand at some of the popular incandescent mods that are being posted, and figured I'd start out easy with some KPR112 and KPR118 mods (while I work on acquiring parts for the more powerful mods). I'm familiar with the various options for using CR123s and AAs in 2 cell C and D Maglites, but I have a couple of questions:

1) Does anyone know what lumens the KPR112 and KPR118 are normally rated at? I've found the equation for re-rating lumens based on the overdrive/rated voltage ratio, and I've found the rated voltages for the KPR112 and 118, but I haven't been able to find the last part of the equation, the rated lumens for the bulbs.

2) What voltage are 3 CR123A's actually supplying? I know they're called 3 volt batteries, but have read that they actually start out a little higher (3.2 or 3.3v?), but will then sag under load to maybe something less than 3v? What voltage should I use per CR123A when trying to figure out if I'm overdriving a bulb too much, or in recalculating lumens using the overdrive/rated voltage equation?

3) Same question as above for multiple AAs. Do alkaline AAs really supply 1.5v each, and NiMH supply 1.2v each, when figuring overdrive tolerance and recalculating lumens?

I'm basically trying to get an idea of how powerful the KPR mods are compared to various stock flashlights and the more powerful mods. The lumens re-rating equation seems like a nice standard tool, and as an engineer I like calculating and tracking things in spreadsheets (but as a civil engineer who squeeked through my basic circuits class way back when, I'm still learning some of the terminology here /ubbthreads/images/graemlins/crazy.gif). Any help would be greatly appreciated. Thanks!

the beakman

NiMH cells actually supply more than 1.2v initially and hold 1.2 volts or higher very well until close to going dead, while alkalines supply 1.5 initially and drop pretty rapidly. Good quality NiMH will easily supply up to 3 amp loads, and the high current ones may supply 20 or more before running in to trouble.

How much they sag is completely dependant on load. Using 112 and 118 bulbs, there isn't that much sag at all with NiMH cells.

123's sag anytime you go over about 1 amp.

Alkalines just flat won't deliver enough current to drive any of the hipower bulbs, so they are not an issue for most of us. I haven't had much success at all with anything over 1 amp.

Bill

3x123 is pretty well documented to drive a 5 cell (6.0V nominal) bulb safely. That indicates some pretty good sag.

I would not really try more than 6 NimH against the same bulb however.

4x123 + 1LithAA is pretty good against a WA01318. I have never considered a NimH setup for that, although it would be WAY WAY cheaper to run!!! Figures out to 11.25 NimH voltage wise, but without the sag 9 might be correct...

I've been told that the 1318 although overdriven will work with 8xAA NiMH's.