Batteries for P7 Mag mod?

[sunshine57]

I'm reaching out for opinions on the best battery setup for a P7 mag mod direct drive. After I try this, I'll get into drivers and increased input. All the info I see gets me to a 3 or 4 AA nimh setup, at 3.6 to 4.8 volts respectively. Most data sheets show amps, and I don't know the conversion method. so the simple answer is the best! LOL.

Thanks in advance

 

[Norm]

For DD 4 X Nimh is too many and 3 is just right. Works well with Vf: I = 3.25 - 3.50V. What is the vf or your P7?

Norm

 

[sunshine57]

Not sure, its a DXSPJ from brightlumens. Think it was listed for 3.50-3.75. and thanks for the input. do'nt want to fry the first one and get spooked.

Dave

 

[Norm]

I would go with the 3 Nimh, check your current draw for a good few minutes, it will be decreasing, initial draw may be around 3 Amps or just over but I'm sure it should settle back to a comfortable level.
Norm

 

[blackdragonx1186]

3 D nimhs would work nicely.

 

[M@elstrom]

+1 Agreed! :thumbsup:

I'm currently using 3 'D' Alkalines (possible due to voltage sag) but 3 high capacity NiMH D cells would be perfect (I still haven't got around to getting mine), although manufacturers claim upwards of 2Ah (2000mAh) on various AA NiMH batteries they don't always hold that much :(

Better to have substantial reserve capacity than suck the life out of an underperforming AA NiMH cell, what size/type of host were you planning to work with for this P7 project?

 

[sunshine57]

I was planning to stay as small as possible with a 3 or 4 aa nimh setup by one of the members. I was also considering an 18670 to use the same size. Also still looking for the most proven build instructions. I have mainly stayed with the incan mod until now, with the P7 giving 900 lumens I need to branch out!

 

[Superdave]

I'd use a driver circuit and run 2 18650's in series. That's how my 2D with a P7 is setup, works great and the driver circuit was like $12 from KD.

You'll need a battery spacer depending on what host you use though, but those are easy to make. ;)

 

[Northern Lights]

I'm reaching out for opinions on the best battery setup for a P7 mag mod direct drive. After I try this, I'll get into drivers and increased input. All the info I see gets me to a 3 or 4 AA nimh setup, at 3.6 to 4.8 volts respectively. Most data sheets show amps, and I don't know the conversion method. so the simple answer is the best! LOL.

Thanks in advance

remember your specification rules for LEDs, Maximum output comes from Maximum FORWARD VOLTAGE, Vf.
For the P7 what has been out there right now is:
C bin, luminous output 700-800 lumens using I bin, 3.5 Vf voltage
and
D bin, luninous output 800-900 lumens using J bin, 3.75 Vf voltage.

That is the combinations offered by the manufacture that I have been able to get a hold of. Both LEDs by the published specification would be operating at 2.8 amps. Both can take a little more power, Amps, and thus burn a little brighter.
A driver, constant current to deliver 3.0 amps solves the problem, any supply and either LED otherwise you need to match Vf to Vbatt.

Direct Drive The 3.5 Vf on lithium Ion at 3.6 Vbattery nominal voltage from 18650s, AW C cells, Kaidomain Li-ion D cells etc. Remember the LED runs at 12 watts, so you need a fairly good capacity, the smallest 18650 I use is 2500 mAh, (2.5 Ah) .
If you put a D bin, J bin on a Lithium Ion at the 3.6 volts you are loosing potential and may even be dimmer than if you used the C bin on those batteries.
The emolie at 3.7 Volts, I use the Milwaukee tool pack versions, are the correct Vf for J bin P7. Boy you get light. They charge fast too, the 2950 mAh capacity can be recharged at 5 amps. It takes minutes not all day to recharge those with a RC type charger. There are cheap 1.5A chargers for lipoly at batteryspace.com that work well for these too. Lipolyl chargers can charge emoli cells.

The emoli is also capable of high drain so under an LED the discharge curve is very flat and resembles a driver curver so it is a nice combnation expecially if you give it modes using the taskled.com D2Flex PWM controler.
Here is an example of such a project,
SOLD-RECHARGEABLE 2C P7, Modes, Electronic GID & more features

 

[jcvjcvjcvjcv]

The point with the J bin is that you aren't driving it to spec most of the time with 3x Ni-Mh. I have the I bin DD on three AccuPower Evolution 10,000 mAh and it works great. Thinking of doing one with a 2D @3C. Still have two heatsinks left :naughty:

 

[M@elstrom]

Amilite sell the I spec 3.25~3.5v Vf D bin P7's, that's where I got my DSWOI from anyway :thumbsup: