Batterys in Parallel

[jawnn]

I need a p7 flash light or equivelent that uses 3 or 4 of the 18650 batterys in parallel to really get more run time.
But where can I get one?:candle: And is actually that simple?

 

[jankj]

Most multicell P7 flashlight I've read about do their batteries in series, not parallel and use a driver to convert the higher voltage down to ~3.6-3.7 volts. Some energy is lost in this process, but it is still beneficial (longer runtime and better regulation).


As I understand it, the 18650 is well suited for driving the P7 directly (unregulated, which means no electronics except perhaps a resistor is involved in controlling the curent or voltage that the LED receives), so doing a couple of those in parallel is an interesting idea. Personally, I would lean towards using them in series with a driver because this will give you a regulated light (which I would prefer in this application). An unregulated ligth will get dimmer as the battery drains. The light output from a regulated light will not change before the batteries are almost completely depleted.


You could check out the battery forum if there are anyone who has discussed 2 or 3 18650 's in parallel - or ask your question there.


Honk Kong based dealextreme.com (short: DX) or kaidoman.com (KD) have a multitude of P7 lights with 1, 2 or 3 18650 batteries. Quality is somewhat a lucky lottery, but if you get a good sample they're the most bang-for-the-buck. You can either use the lights as they are (strapped to your helmet or the handlebar) or customize your own battery package. Or pay more money for higher quality from another vendor. There's lots of reviews of these lights on the CPF forums, search and you shall find

 

[ktronik]

4x 18650's in a 4 cell holder in parallel with a AMC7135 driver with dimming into a P7 will work just fine...

K

 

[trbdck]

Search the forum, there´s a guy doing ready kits for an MTE P7 flashlight. The kit includes the battery holder, and a dummy cell to fit into the light. You won´t find a holder for 18650 cells anywhere else. Strange thing, but they just don´t exist.

 

[pushy]

I run 3 DX P7 flashlights on external battery pack and have never had any problems. My rides are between 3 - 4 hours at night.

I use 4x18650 pack

Shed door is 50ft away camera setting f3.2 55mm lens ISO200 2sec exposure. The hotsopt is because I have glued DX sku4584 to the glass lens of one of the flashlights.

 

[ebrady]

Are you are using protected or unprotected 18650's in your pack? I am thinking about a similar project and am wondering if protected 18650's in parallel would cause problems?

 

[pushy]

Are you are using protected or unprotected 18650's in your pack? I am thinking about a similar project and am wondering if protected 18650's in parallel would cause problems?

Protected - used the ultrafires 2400mA for the last 12 months at least on 40mile rides 3 or 4 nights a week recharging after every ride.