Every single battery I see has its energy capacity cited in "milliampere 
hours"; it'd be a hell of a lot handier if they were cited in "milliwatt 
hours", or even joules.

I need roughly a 5 V supply for my project but I'm thinking of using a 
1.5 V supply and stepping it up to 5 V for the microcontroller... but 
I'm looking at batteries that have different voltages and so I've to do 
some maths to change the milliampere hours to milliwatt hours.

Anyway moving on...

My project will consume a peak of about 800 mW or thereabouts. The 
average power might be something like 300 mW.

A single AA battery is 1.5 volts and has 650 milliampere hours... which 
is equal to 975 mW hours. So I'd get about 3 and a quarter hours out of 
one AA battery.

It'd be cool if I could use one of those small button-shaped batteries; 
does anyone of a very small battery that has a capacity somewhere in the 
hundreds of milliwatt hours?

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist