Re: Weighty matters
You might wanna look at 'fag' batteries Lester.
these newish small lipos are readily available now as they are used in the vapor fag things.
tons of different sizes, but for example a 14500 is AA sized. It can come with short circuit protection circuitry built in and has a capacity of around 800mah.
And since it's at 3.7v nominal will typically power arduino stuff, etc without the need for a booster. However even if you still use a booster - you get a lot more capacity that ultimate lithiums.
The other benefit is, being AA sized you can stick em in a regular AA battery holder - pair em up, etc.