Need help sourcing a battery for my project?

I'm in the development stage for my next couple of projects, and after thinking about variables and other such random stuff, I've decided on a project (no, I won't tell you what it is. not yet at least!). The project is going to have to be very small, and will really be stretching the limits of through hole soldering (I dont want to to SMD on this). Due to size constraints, and power consumption, I need a very specific size battery. I need a battery with (I hope) at least 700mah capacity, if not more, as well as be rechargeable. Diameter should not exceed that of an AAA battery (around 12mm or so). Voltage CANNOT be 1.5, and must be more than 2v (single batteries only please! Multiple cell batteries are fine, as long as they are in a single package). Length of the battery can be pretty long, but should not exceed more than 40mm or so. Battery can be any rechargeable type, with the exception of Li-ion flat packs (I think they are a bit too fragile and volatile for a project exposed to daily wear and tear.). My current choice is a 123A li-ion 880mah battery, but it is a bit too wide for me.. Anyone know of a good, rechargeable, small battery? I know this is really stretching my choice limits, but I would GREATLY appreciate any help you give. Many, many thanks in advance, 
-Thomas

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Use a AAA 1.5V battery and a boost converter.
astroboy907 (author)  steveastrouk5 years ago
What about thermoelectric?? Basically, the project will draw about 10-20ma @3v- would a small Peltier (1x2 in) hooked up to a power harvester be able to source ~15ma at all times (touching human skin for heat and exposed to air on the other side). There might be 80ma power burst draws (for 2sec approx), but I have not decided if I want to include the LEDs to draw 80ma. Of course I would have a small battery backup and probably a boost circuit...
rickharris5 years ago
Your not going about this in the right way. Unless your willing to pay a manufacturer to make a battery to your specifications then your bound by the commonly available products and their sizes.

You need to rethink your design effort and start with a common battery that provided enough power - this may be a single cell or multi cells. then design the rest around that.

It is no good hoping for a lucky shot to give you just what you need. Why not make the battery a separate item and connect with a lead - long or short for example.
astroboy907 (author)  rickharris5 years ago
Needs to be super-portable/not bulky. I know there is a battery out there, I'm just trying to find an actual battery with enough capacity and voltage for my needs in an acceptable size. Fir my size of project (around 2x2x1 in), its going to be really hard to find something, and I really dont have enough money to manufacture it. I have been looking at a small flexible solar panel (50ma), which would probably provide the 10mah draw from the project in most light (which would make my requirements for the battery a lot less, about half the capacity, if that), but then I need to draw up a plan for a power switcher circuit.
When you take Li-ion out of the list you pretty much eliminated your best options.

Just about every small form factor device sold now days uses a li-ion flat pack of some sort. You can't say a typical cell/smart phone doesn't see daily wear and tear. The packs themselves, when secured properly, stand up just as well as any other battery. They are just picky chargers. Meaning you need to have good control of how they charge. The only difference in the flat packs and the 123A is the 123A comes in a thin metal cylinder.

A quick google search of 3V AA sized batteries came up with this.
http://www.batteryjunction.com/titanium-cr14505-craa--3v.html?gclid=CLbiz7bMxbECFYNx4AodwlcAGw
astroboy907 (author)  mpilchfamily5 years ago
Ive been checking around.... Li ion (or even lipoly) seems to be a pretty good option, if it is in a case (or otherwise protected from metal shards). I just need something that will stand being mildy smacked around and not explode (as it will be on-person. A motorola BR50 battery seems "almost" the right size (and I have a few dead ones lying around too)