I am designing LED torch using this LED
http://www.mouser.com/ProductDetail/Lite-On/LTW-110TLA/?qs=rlI5kRZuhCb3TMOE0213Og==

It draws about 10mA and give max 0.8 lumens

I need to find this type batteries which can supply 10mA about 15 hrs.
http://www.homedepot.com/p/Energize...ries-2-Pack-2025BP-2/202547254#specifications

Is this possible?
battery size is very important. It should not be thick than 2.5mm

I noticed that many small batteries can not draw large current

 

The 27 lumens per watt sounds quite reasonable.

Finding a watch battery that can sustain 10 ma will be a challenge. You might want to try a stack of NiCd button cells or maybe even an NiMh button cells.

NiCd button cells (examples)
www.powerstream.com/p/280K.pdf

NiMh cells (examples)
www.gpbatteries.com/hk/images/prod/.../NiMH_Button_Catalogue.pdf

 

Type 2032 batteries have no intentional current limiting on them, as do many of the smaller coin-type lithium batteries. It's common to see two of them in series used to power a stubby LED flashlight (torch).

 

can i find 3v this type battery. this one is 1.2v

 

The CR2032 is a 3V lithium.

 

yes but 2032 can not give 10mA. it has designed for low current such as 1mA.
above suggestion of nicd cells is very good. i am try to find 3v battery very thin and need to deliver 10mA about 15hrs

 

The CR 2032 is rated at 190 to 235mA, so it will take 10mA for 19hours minimum.


http://data.energizer.com/PDFs/cr2032.pdf

 

yes but 2032 can not give 10mA...

If you put two CR2032 in series, I think you'll be pleasantly surprised at the amount of current you can get, and the battery life. Smaller cells like the 2025 or 2016 have a maximum current drain specified, but not the 2032 (although it is, of course, limited by internal resistance).

I'm not saying that you can necessarily get your 15 hours, but if you can't, then just use more batteries in parallel. You'll still have the 2mm thickness if you build out instead of stacking the cells up.

2xCR2032 is used in these little flashlights that I have, and the life is quite good.