# Malkoff M60 with 4 123As

#### toasterlocker

##### Newly Enlightened
Okay, so I'll just come out and say that I'm not very good with the technical stuff relating to batteries and such, and after trying to figure it out myself (admittedly only about 5 min) I decided I would just ask...

Will 4 123As with a plain old M60 cause any damage? I ask because I bought an extension tube for my 6P which adds one 18650 or two 123As, and I just want to make sure running four 123A won't be a problem.

I'm planning on getting some 18650s to run eventually (which I heard works fine), but for now I have a LARGE supply of 123As (work pays for them :devil!

From my elementary understanding, I'm assuming there will not be a problem, but I would rather be safe than sorry.

#### Justin Case

##### Flashlight Enthusiast
The Malkoff web sites says that the M60 can accept input voltages in the range of 3.8 to 9 volts. Four primary 123A cells likely would exceed the 9V upper limit.

#### NotRegulated

##### Flashlight Enthusiast
The Malkoff M60 will not take 4 123's. 3 123's are the limit.

Which extension tube did you add to your 6P that adds 2 123's or one 18650?
A Surefire A19 extension tube adds one 123 making it into a "9P".

M60 + 4x123 =

#### toasterlocker

##### Newly Enlightened
So, will two 18650s work?

#### Siskik

##### Newly Enlightened
2 x 18650 should start out just under 9 volts. Should be OK. I run an M60 w/ 2 x 18500's.

3.7 (4.2 off the charger) times 2 is 8.4 volts.

#### kramer5150

##### Flashaholic
First thing you need to know is how to interpret the cell sizing code. Lets use a primary CR123 as an example.

Its size code is 16340.
16=diameter in mm
34=Length in mm
0=designates the shape code, "0" for cylinder

An 18650 is 18mm diameter, 65mm long, and cylinderical in shape. And so on...

If you are using a 6P as a host the ONLY cell combination you can fit are 2x16340, 1x17670, 1x17500+dummy spacer, 1x16340+dummy spacer.

The good thing about the M60 is it was designed for use in the 6P. Hence its been optimized to get the most out of 2x16340 (either primaries or RCR).

If you want to extend run times in a stock bore surefire body, you can power up to 2x17500 if you add a 1-cell extender, or run the M60 in a 9P with those 2x17500 cells. You can also use a 1x17670 with a 3.7 volt module.

You can not fit an 18mm diameter cell (in any length) in the 6P, as its only bored out for ~17.35mm. If you want to bump up to any 18mm cell, you are going to have to modify the 6P body or use one of the leaf 18mm bodies. The latter being my preferred method.

IIRC Surefire did make a 12P (someone please correct me). That will physically fit 4xCR123, but as others have mentioned you will cook the M60.

Leaf makes a 2x18650 body, that would be your best bet if yuo want the added run time of 18650 cells.

#### toasterlocker

##### Newly Enlightened
Well, I thank you for taking the time to explain that. I guess I just assumed an 18650 would fit in a 6P since I've seen all these other lights that take one 18650 or 2 123As.

This is the extension tube I bought.
http://www.lighthound.com/Solarforc...Tube-for-18650-Battery--L2-E18_p_10-2808.html

With this tube and a 6P, what would be the best battery combination? I bought it thinking 2 18650s would work and 4 123As would be okay in the short term, but clearly now I was wrong.

#### StandardBattery

##### Flashlight Enthusiast
Well, that tube would allow you to load 4 CR123 cells (with a lot of rattle on two of them), but as others have pointed out that is too much voltage for the Malkoff drop-ins.

You could wait until this Body comes back in stock, then you would have the option of 18650, or 2x18650 (when combined with your extension). This would work well with the Malkoff M60 series (2x18650) and gove very long runtimes. Or you could use the M30 with 1x18650. You can use the M60 with 1x18650, but it's not going to be optimal.

I didn't know about that extension you bought and it is quite interesting because 2x18650 and some new high powered LEDS are going to be quite exciting if someone can figure out a way to manage the heat.

Have Fun!

#### kramer5150

##### Flashaholic
Well, I thank you for taking the time to explain that. I guess I just assumed an 18650 would fit in a 6P since I've seen all these other lights that take one 18650 or 2 123As.

This is the extension tube I bought.
http://www.lighthound.com/Solarforc...Tube-for-18650-Battery--L2-E18_p_10-2808.html

With this tube and a 6P, what would be the best battery combination? I bought it thinking 2 18650s would work and 4 123As would be okay in the short term, but clearly now I was wrong.

2x18650 cells is not going to work, the stock 6P body is only 17.5mm. You are going to have to upgrade the body tube to 18mm. You need one of these to go with that 18650 extender:
http://www.lighthound.com/Solarforc...ed--2xCR-123-or-1x17670-battery_p_6-1624.html

I don't know if a pair of 17670 cells will work with your 18650 tube extender and the 6P OEM body, and you CERTAINLY do NOT want to attempt to pair a 17670 with an 18650.

#### Illumination

##### Flashlight Enthusiast
Note you can also use the tube you have with 3 CR123s and a dummy cell. They should be pretty easy to find... I think AW, Battery Junction and Light Hound might have them, among others. I think the dummy cells are just wrapped aluminum so that the dummy carries current down the axis but does not short on the sides. (If you are handy you should be able to make them yourself...a 34mm aluminum cylinder the width of a battery wrapped around the sides in electrical tape should work fine.)

You are probably going to want to insert some kind of wrapper around your cells so they don't rattle - as others have noted the tube you has accommodates 18mm cells but the cr123s are only 16mm diameter. You could probably use a piece of plastic sheeting to minimize rattle. The Olight M20 solved the problem with an innovative battery carrier - use it for 16mm cells or remove it for use with 18mm rechargeables.

The M60 is an awesome accessory for a C2.

#### toasterlocker

##### Newly Enlightened
Eh, I don't really want to bother with a dummy cell. That would defeat the purpose of getting a longer extension tube in the first place. If I can't find something that allows me to use the whole light, I'll probably just sell the tube.

#### toasterlocker

##### Newly Enlightened
I don't know if a pair of 17670 cells will work with your 18650 tube extender and the 6P OEM body...

Thanks, l'll look into that. I may just end up getting the new body you suggested.

#### toasterlocker

##### Newly Enlightened
I don't know if a pair of 17670 cells will work with your 18650 tube extender and the 6P OEM body...

Hey, so I just did some math.

The OEM 6P plus the 18650 body would be 133mm in battery length going by the breakdown you posted earlier (assuming two 123As and one 18650, as that is what each section was designed for.) Two 17670 cells would only be 1 mm longer, so I think it would work. We may have found a winner!

Come pay day I'm gonna buy two 17670s and a charger. I'll let you all know how it works out. If this works, it will be awesome, as that one extension tube on its own is a lot cheaper than buying a whole leef body.

#### NotRegulated

##### Flashlight Enthusiast
Two 17670's will work fine.