"Alternative" battery

[Lucacri]

Hello,
I'm in a quest to find a nice battery for a regulated 5v box. Right now I'm using two 14500 900mah and they last a day. The only problem I see with those batteries is that since they are round, there is a "lot" of wasted space that could be used for more mah
Also, those batteries are 1C, that means that they safely discharge only 900mah each and it might be not enough to power the atty.

So, i found this battery:
Polymer Li-Ion Cell: 3.7V 1400mAh (703562-10C) 5.18Wh, 10A Drain Rate - UL Listed

I never used the flat batteries before but they do look good! 10C, 1400 mah and only 7mm thick. The idea is to stack two of them and they should (correct me if I'm wrong) fit almost in the same space as two 14500, but with almost double capacity and 10C!

Am I totally wrong? I see also that you need a special charger for those batteries and I was thinking about making a "plug" inside the box so that I can charge the batteries without taking them out. Is this charger good for charging both of them with one cable?
Smart Charger (1.2A) for 7.4V Li-ion/Polymer Rechargeable Battery Pack -- UL listed

 

[Dale.s]

You are correct. nuff said! Ok few things to add, each cell should have its own protection (just to be safe) and you will need some kind of load balancing for the charger. Ive been looking at li-po's also and i cant wait to try them! That battery is also 35mm wide, if your using a 2AA box it wont fit, most 2AA boxs are 33mm (1.3 inches).

Edit: The more i think about it, you will connect the 2 cells in series, increasing the voltage of the cell pack, so you would not need load balancing as they would effectively balance themselves. You would need a li-ion charger to charge to the 8.4V but that should be all thats needed. If you where to make a 3.7V device using 2 of these cells for a "all week vape" then you would need load balancing yada yada yada.....

 

[Lucacri]

Great! I'm not alone!
Is this one a good candidate for the PCB and load balancer?
PCB for 7.4V Li-Ion Battery Pack (8A +/-1A Limit)
What do you think?
My idea was to put the two batteries one on top of the other and inside a 4 AA box (taking away everything from inside).
One "column" would fit the recessed atty, another one will fit all the electrical components and the button and the other two (a bit more than two, as you said) will fit the batteries.
Or am I forgetting something?

 

[Dale.s]

That looks like its the perfect choice. Get busy and show us how it works! Not many people are using li-po yet and i cant wait!

Edit: Im also looking at making a small box mod for 5v vaping fun, my plan is get a 2aa box, find the highest ma li-po i can fit (with a little room on top for the circuitry ) and using a 5v boost regulator to get 5v vaping of a single li-po cell!

 

[Lucacri]

Nice idea! In that case how many mah will you loose to get to 5v?

Anyways, I bought everything. I was wrong with my calculations, the batteries I choose are a bit bigger than the 4 AA box, so I'm also looking for a nice plastic (or even metallic) box that will fit: two batteries, the PCB, the recessed 801 atty connected via RCA, a recessed female RCA at the bottom so I will charge the batteries without removing them (and/or while vaping), and... A SMALL BOTTLE (2-3mm) of reservoir (Moon stile)

Any ideas?
This, I hope, will be my last project and it has to contain everything I always wanted to have. It will be my dream ecig