Powering a pi zero portable via AA batteries

CodeDrawer

So I saw a post on the forum about problems with bringing lithium batteries on a plane.

So I decided to do some math and here is what I found.

Energizer AA batteries have 4.2 watt hours in them. The pi runs on (at a maximum) of 96 watt hours in a day. Divide that by 24 gets you the watt hours per hour (4). Each battery has 4.2 watt hours. So if you are using four of them, you get 16.8 watt hours. So for a grand total, 4 AAs will last a minimum of 4.2 hours. Please correct me if I'm wrong.

Capeman

If you power a pi on 4 AA (in series I'm assuming), you'll be working with 6v which means you'll probably have to run that source through a battery eliminator circuit or a DC stepdown circuit to get the 5v you need for the pi. I know most good BECs run at 87% efficiency, not sure how efficient stepdown circuits are, but you'll likely be losing about 10 to 15% of your power to conversion. So 4.2 hours may become like 3.9ish... But still, math sounds ok to me, but honestly calculating anything in electronics always gives me a headache.

moosepr

@CodeDrawer I have been playing with different power sources on my GBZ project. Had the similar light bulb moment when I saw that alkaline cells can offer 2000mah and my eyes lit up.

My testing unfortunately revealed less success. I was banking on the fact that the pi will actually run on 3v, and so you could just run unboosted, but again, that didn't work out well!

I'm sure that 4 cells in series, dropped to 5v would give better results, but I guess the only real way to tell is to have a test!

You can read through my testing on my project page over on hackaday https://hackaday.io/project/20152-gameboy-zero-but-smaller

Capeman

You could try a small voltage regulator. This one takes input from 6 to 23v and outputs a constant 5v 2a(max). Not sure how it would perform once the battery pack drops below 6v as your batteries become depleted though.

https://www.getfpv.com/diatone-5v-2amp-voltage-regulator.html?gclid=CjwKEAjwpdnJBRC4hcTFtc6fwEkSJABwupNidJdYjIwOJL_t2O3GlaMdiaGBHvlCjrYcnyjKyhbrERoC4Dzw_wcB

moosepr

Pololu are good for voltage regulators

This one can make 5v from a massive range of input voltages
https://www.pololu.com/product/2836

Tend to be pretty tiny too