How to Make.. The BM-DS91    Double Stamina  Box MOD (nov 2011)
Build Your Own !



This is simple battery case mod.  (also known as a puck)

You will find DIY mods like these on e-cig forums, .eg there's one on ECF which uses a smaller battery case which is quite good, but I decided to go for a bigger case for a better grip and extra battery for longer life.

Battery mods basically replace the battery part of your e-cig.
The design is really simple. It's basically just this list ;

Atty socket.
Battery holder.  (size AA 14450 li-Ion protected batteries @ 3.6V or 3.7V)
Operating Switch.
Master Switch (optional)



Mods like these are easy to make because they use parts commonly found in electronic parts stores. And because you put the parts together, it's easy and low cost maintenance.

 
Atty Socket  




T
he easiest way to get an atty socket is to remove one from an old battery.

You will need an old batttery and an old atty. Instead of throwing them away, screw the atty to the battery and grip both ends with either pliers,spanners or two pieces of hollow pipe.

By slightly bending and rotating about the joint, you will be able to slowly pry the socket away from the battery.

Once you have the atty socket out, then you can remove the anode (the centre part) by pushing it out from below with a toothpick. Becareful not to damage the rubber separator ring.

Solder a peice of wire to the anode.
Solder  a peice of wire to the outer shell near the bottom.
Re-assemble the anode back in it's shell.

Drill and/or burrow a hole on the side of the batttery holder that will just fit the socket as shown below.
Fix the socket to the hole using 2-mix glue or hot-glue so that it will not move.


Battery holder
A 3 cell AA batery box can be bought at an electronic store.
They are fairly standard and only cost as low as US$1.

These boxes come with their own built-in master swich.
You will have to re-arrange the contact plates to fit two 3.7v batteries in pararallel, that is the two +ve ends should be touching each other. And the same for the other side (-ve).

This means you have the option to put in just one battery. Or two batteries for longer operation.


Operating Switch

Master Switch

Operating switches can be bought from the electronic store. You can choose any style you want. This white button one is a soft switch as I prefer them to the hard-clicky-type ones.

It's up to you. Just be sure it fits in the box.
(Tip: Don't choose a switch too small, it may not be able to handle high current).

Make a slot/hole in the box for half the switch with a file and fix it in position with 2-mix-glue. or hot glue. Also make a slot/hole on the box-lid and some room for it to slide in shut.

( Switches that are under-rated tend to burn out quickly with use. The first thing you notice is that their internal resistance builds up making your battery run out faster and also poor vapour.)


Wire up one end of the atty socket (e.g centre pole) to the nearest battery plate (red wire).

 If there's not enough room to  close the lid, you may have to recess (make a ditch) on the plastic side that holds the battery.

Wire up the other atty socket contact (e.g outer rim) to one end of the operating switch (black wire).

You can barely see it in this pic but the end of the master switch is threaded and soldered to the other contact of the operating switch (white dash).

That's It !





Did You Know ?

The advantage of these mods over thinner-battery-tube mods is that a proper sized switch can be used. Smaller switches in other mods are usually of the 'dip' (dual-inline-package) style which are rarely rated for high current. Considering an LR atty at 1.5 ohms on 3.7v will run around 2.5 amps, these inferior switches can breakdown or build up a resistance, lowering the current.