4D maglite P7 mod?

Looking to mod my 4D maglite using a britelumens heatsink and P7 combo.

Just have a few questions..

Can i run a P7 off 4 x 1.5v batterys (6volts)?

Do i need a driver or resister?

Regards.

To drive the P7 needs upto 3,7 volts so you will need a regulator to reduce the voltage from 6Vdown to 3.x volts, depending on the bin of your LED.

cir2kuk said:

Can i run a P7 off 4 x 1.5v batterys (6volts)?

Do i need a driver or resister?

Click to expand...

If you mean alkalines, yes. My 4D P7 uses a linear regulator, and drops out of regulation (effectively into direct drive) after only about 5 minutes. But if you want the option of running from any of KOH, NiMH, or NiCd, you'll need some sort of regulation. (Well, a resistor would work, but it would hurt the already poor performance of KOH batteries.)

An 8xAMC7135 driver works quite well for this, as long as it's properly heatsinked.

Where can i get a 8xAMC7135 driver in the uk? or via ebay?

Also i would like to run it off 4xAA (2500mah) rechargeable batterys.

What resister would be needed, if using rechargeable AA's?

cir2kuk said:

Where can i get a 8xAMC7135 driver in the uk? or via ebay?

Also i would like to run it off 4xAA (2500mah) rechargeable batterys.

What resister would be needed, if using rechargeable AA's?

Click to expand...

Kaidomain has a 2.8A driver that is reported to be 8xAMC7135, but I just picked up a 10-pack of 1.4A (4xAMC7135) boards from DX and soldered 2 of them back-to-back.

Not sure why you want to use a resistor, but the resistance needed varies with the Vf of your particular P7, the internal resistance of your AAs, the resistance of the Mag, and the resistance of your battery carrier(s). Somewhere around a quarter of an ohm, and at least 2 watts, would be a sane starting point if you can't determine the approximate characteristics and calculate the right value.

If it were me I would definitely stay away from alkalines. They can't power a P7 at full power and have any decent amount of runtime. I would invest in some good batteries. Alkalines are also prone to leaking.