2x18650 direct drive P7 mods: current?

GarageBoy

Flashlight Enthusiast
Joined
Jun 12, 2004
Messages
3,975
Location
Brooklyn NY
What is the current a P7 sees while driven by 2x18650s? Wondering if its worth it to get a regulator
 

JohnF

Enlightened
Joined
May 10, 2005
Messages
353
I'm no expert, but:

2 x 18650's in parallel could work direct drive without even a series resistor if the vf of the emitter was on the high side. With the batteries in series, you'd generate a bit of heat from a current limiting resistor, so a driver like the hipCC from 'taskled.com' would be more efficient.

John F
 

vestureofblood

Flashlight Enthusiast
Joined
Jun 19, 2008
Messages
3,211
Location
Missouri
I am going to assume that you are wanting to use 2x18650s in parallel, because your led DD on 2x 18650s would not last a full second:poof:.

On 2x freshly charged 18650s in parallel you would probably see about 3.4A and then the current should drop to around 2.8-3.0 amp for the better part of the cycle.

If you are wanting to use the 2 cells in series DD an MCE wired 2S 2P would work. There are a couple of trick that can be done with a cheap 2$ 7135 driver that would give around 3 amp and you would also have reverse polarity protection. If you decide this is something you are interested in I will elaborate.
 
Last edited:

CampingLED

Enlightened
Joined
Nov 13, 2007
Messages
612
Location
South Africa
Vf on the P7 is as follows:

H 3 - 3.25V
I 3.25 - 3.5V
J 3.5 - 3.75V
K 3.75 - 4V

I and J are the most commonly available ones. You can still take a chance to DD drive with 18650 in parallel for J bin, but for I it is better to use a regulator.
 

Latest posts

Top