Timson got you covered on the heat issue part, but choose the Borofloat over the UCL, because it can withstand more heat. If you will need the Kiu bi-pin kit will depend on if you are going to use potted bulbs or not. Fivemega is soon coming with a
adapter that let you easily switch between using both.
I wouldn't buy the first and best batteries off ebay, there are a huge difference between the voltage different types of cells manages to supply to the bulb, and hence there will be a big difference in brightness. And don't believe the stated capacity of the cells.
I have test results for the following NiMH D cells: AccuPower 11500 mAh, CTA 12000 mAh and Powerex 11000 mAh. and I will give you runtime and brightness for each type of cell for each of my bulb suggestions.
I don't have a Mag 6D so I have not tried the following setup myself, but they are based on actual measurements of the batteries and the specs of the bulbs.
Alternative 1: Pelican Big D SLA bulb - potted (can be bought from
www.brightguy.com)
With Accupower batteries:
MPV=7.38V, Bulb lumens=1238, Torch lumens=805, Runtime=142 minutes, Lamp life=2 hours
With CTA batteries:
MPV=7.05V, Bulb lumens=1055, Torch lumens=686, Runtime=129 minutes, Lamp life=4 hours
With Powerex batteries:
MPV=7.05V, Bulb lumens=1055, Torch lumens=686, Runtime=116 minutes, Lamp life=4 hours
Alternative 2: WA1111 bulb - bi-pin or potted (Fivemega or
www.Light-Edge.com)
With AccuPower batteries:
MPV=7.38V, Bulb lumens=959, Torch lumens=623, Runtime=170 minutes, Lamp life=8 hours
With CTA batteries:
MPV=7.05V, Bulb lumens=817, Torch lumens=531, Runtime=159 minutes, Lamp life=14 hours
With Powerex batteries:
MPV=7.05V, Bulb lumens=817, Torch lumens=531, Runtime=143 minutes, Lamp life=14 hours
Alternative 3: Osram HLX 64265 - bi-pin (can be bought
here, note that I have not tried them)
With AccuPower batteries:
MPV=7.2V, Bulb lumens=1448, Torch lumens=941, Runtime=115 minutes, Lamp life=11 hours
With CTA batteries:
MPV=6.9V, Bulb lumens=1247, Torch lumens=811, Runtime=108 minutes, Lamp life=18 hours
With Powerex batteries:
MPV=6.9V, Bulb lumens=1247, Torch lumens=811, Runtime=96 minutes, Lamp life=18 hours
Alternative 4: WA1274 bulb - bi-pin or potted (Litho123)
With AccuPower batteries:
MPV=7.38V, Bulb lumens=603, Torch lumens=392, Runtime=228 minutes, Lamp life=30 hours
With CTA batteries:
MPV=7.05V, Bulb lumens=513, Torch lumens=333, Runtime=209 minutes, Lamp life=51 hours
With Powerex batteries:
MPV=7.05V, Bulb lumens=513, Torch lumens=333, Runtime=188 minutes, Lamp life=51 hours
*MPV=mid point voltage
The WA1274 is the bulb closest driven at spec, it is slightly overdriven with the AccuPower batteries and slightly underdriven with CTA and Powerex batteries. The other bulbs is highly overdriven and may be prone to instantflashing, especially if AccuPower batteries are used.
Edit: Found the lifetime spec of the Pelican Big D Nicad version (30 hours), assumes the SLA version has the same lifetime. Rerated lifetime added for the Big D bulb. Not a recommended setup when we see the short lifetime.
Sigbjoern