Hi folks:
Those who seek brighter incandescent bulbs, DB4AA, DB6AA, and DB8AA people, and people who contemplate pushing their NiMH's to the limit might be interested in the following ramblings.
Now that it's easy to plug the charging port of one of my modded DB8AA's
into a voltage meter while running, I've measured the voltage drop with
various batteries and various amperage bulbs in the light. Here's what I
found. I was surprised that although the drop was the same in 1800 mAh AA cells and the 2450 mAh A cells that it was much less with the mismatched 4/3 A cells I bought from the educational surplus place.
Voltage per Cell
Drain -- 1800 mAh AA -- 2450 mAh A -- 3000+ 4/3 mAh A -- 3000 mAh C
1.10 A -- 1.15 V -- 1.15 V -- 1.17 V -- 1.20
1.42 A -- 1.08 V -- 1.08 V -- 1.15 V 1.18
1.92 A -- 1.00 V -- 1.01 V -- 1.10 V -- 1.12
3.35 A -- 0.85 V -- 0.87 V -- 1.02 V -- 1.03
The magcharger battery also delivers 1.10 V * 5 at 1.92 A. 5.50 V is more
than I would like to drive the 4.8 V 1.92 A W/A bulb, but it should be quite
bright for a limited number of hours. I feel it is a more satisfying choice than putting the bulb into a parallel DB8AA.
Anyhow, this shows that the 6.27 V 1.42 A 01315 bulb is only slightly overdriven with 6R AA or A cells.
The 01315 may be less overdriven with 7R AA or A cells than with 2 * 123 as I currently have set up and Mr. Bulk is testing.
Voltage drop interpolation corroborates my finding that my P91 mod is much nicer in a 7-cell DB8AA than in a DB6AA. Maybe Aragorn wouldn't have sold his original P91 mod if he'd run it off of a seventh cell.
The voltage drops further suggests that a pair of LS 5 W which specs at 700 mAh @ at 6.8V and 200 mAh at 6.1 V might be effectively self-regulated:
6 AA or A batteries can't deliver 1.4 A (2@ 5WLS * 0.700 A) at 1.13
V (the top of the range.)
6 AA or A batteries can continue to deliver well over 0.4 A (2@ 5WLS
* 0.200 A) at 1.02 V (the bottom of the range)
A third LS would probably guarantee that all three LEDs were under driven to dimmer individual levels than with 2 but would probably be somewhat brighter and more efficient than the 2 LED version.
I'm afraid that a single LS without resistance would be fatally overdriven.
Interpolation also suggests that the 50 hour 3.5 V 2.3 A Carley T-1 1/2 bulb potted into a ceramic PR base should pull around 3.8 V to 3.9 v in a 4AA light. This should generate about 180 L and give about 17 hours of run time. A 3C would underdrive the bulb and a 4C would excessively overdrive.
I don't know what 4AA light can handle the heat. I recently bought extra PT40 bezels and reflectors, so I'm tempted to cut out the center of a PT40 lens for ventilation and see what happens.
The voltage drops suggests that the W/A 4.8V 1.92 A bulb should work wonderfully in a 5-cell DB6AA.
I've decided that the only lithium DB's I'm likely to keep are:
DB6AA and 9.0 V 1.1 A bulb with 2 * 3@ 3V lithium plus 1 @ AA alkaline. (> 2 hour run time and bright.)
DB4AA and 4.8 V 1.92 A bulb with 2 * 2@ 3V lithiums. (should run 45 minutes starting at 5.0X volts at around 240 L. with 5 cells vs 90+ minutes in a DB8AA serial / parallel at about 4.7 V and 190 L.)
The 2 * 3 lithium 01315 combination is probably more overdriven than a 7R-cell setup. I continue to be afraid that the lithium configuration will shorten bulb life excessively.
I've received my Mag charger tempered soda glass lenses and they fit without problem in my regular C and D Mags inspite of MagLight"s caution.
Those who seek brighter incandescent bulbs, DB4AA, DB6AA, and DB8AA people, and people who contemplate pushing their NiMH's to the limit might be interested in the following ramblings.
Now that it's easy to plug the charging port of one of my modded DB8AA's
into a voltage meter while running, I've measured the voltage drop with
various batteries and various amperage bulbs in the light. Here's what I
found. I was surprised that although the drop was the same in 1800 mAh AA cells and the 2450 mAh A cells that it was much less with the mismatched 4/3 A cells I bought from the educational surplus place.
Voltage per Cell
Drain -- 1800 mAh AA -- 2450 mAh A -- 3000+ 4/3 mAh A -- 3000 mAh C
1.10 A -- 1.15 V -- 1.15 V -- 1.17 V -- 1.20
1.42 A -- 1.08 V -- 1.08 V -- 1.15 V 1.18
1.92 A -- 1.00 V -- 1.01 V -- 1.10 V -- 1.12
3.35 A -- 0.85 V -- 0.87 V -- 1.02 V -- 1.03
The magcharger battery also delivers 1.10 V * 5 at 1.92 A. 5.50 V is more
than I would like to drive the 4.8 V 1.92 A W/A bulb, but it should be quite
bright for a limited number of hours. I feel it is a more satisfying choice than putting the bulb into a parallel DB8AA.
Anyhow, this shows that the 6.27 V 1.42 A 01315 bulb is only slightly overdriven with 6R AA or A cells.
The 01315 may be less overdriven with 7R AA or A cells than with 2 * 123 as I currently have set up and Mr. Bulk is testing.
Voltage drop interpolation corroborates my finding that my P91 mod is much nicer in a 7-cell DB8AA than in a DB6AA. Maybe Aragorn wouldn't have sold his original P91 mod if he'd run it off of a seventh cell.
The voltage drops further suggests that a pair of LS 5 W which specs at 700 mAh @ at 6.8V and 200 mAh at 6.1 V might be effectively self-regulated:
6 AA or A batteries can't deliver 1.4 A (2@ 5WLS * 0.700 A) at 1.13
V (the top of the range.)
6 AA or A batteries can continue to deliver well over 0.4 A (2@ 5WLS
* 0.200 A) at 1.02 V (the bottom of the range)
A third LS would probably guarantee that all three LEDs were under driven to dimmer individual levels than with 2 but would probably be somewhat brighter and more efficient than the 2 LED version.
I'm afraid that a single LS without resistance would be fatally overdriven.
Interpolation also suggests that the 50 hour 3.5 V 2.3 A Carley T-1 1/2 bulb potted into a ceramic PR base should pull around 3.8 V to 3.9 v in a 4AA light. This should generate about 180 L and give about 17 hours of run time. A 3C would underdrive the bulb and a 4C would excessively overdrive.
I don't know what 4AA light can handle the heat. I recently bought extra PT40 bezels and reflectors, so I'm tempted to cut out the center of a PT40 lens for ventilation and see what happens.
The voltage drops suggests that the W/A 4.8V 1.92 A bulb should work wonderfully in a 5-cell DB6AA.
I've decided that the only lithium DB's I'm likely to keep are:
DB6AA and 9.0 V 1.1 A bulb with 2 * 3@ 3V lithium plus 1 @ AA alkaline. (> 2 hour run time and bright.)
DB4AA and 4.8 V 1.92 A bulb with 2 * 2@ 3V lithiums. (should run 45 minutes starting at 5.0X volts at around 240 L. with 5 cells vs 90+ minutes in a DB8AA serial / parallel at about 4.7 V and 190 L.)
The 2 * 3 lithium 01315 combination is probably more overdriven than a 7R-cell setup. I continue to be afraid that the lithium configuration will shorten bulb life excessively.
I've received my Mag charger tempered soda glass lenses and they fit without problem in my regular C and D Mags inspite of MagLight"s caution.
