1

I have a raspberry pi zero w. What is the smallest (in terms of weight) that can run the pi? I am not concerned about how long it runs for; 5 mins would be adequate. What about with a camera attached?

I know that 4 AA batteries can run it for quite a few hours, but they weigh about 100g in total. Can I sacrifice run time for weight?

Thanks!

Improve this question

4 Answers 4

Reset to default
1

I think your best chance of success is to find a small LIPO. They are typically used for powering radio controlled aircraft such as quadcopters.

As long as you feed more than 3.3V into the 5V pin a LIPO of large enough capacity will provide the current needed to power the Pi.

Some Pi's have proection mechanisms which kick in at 6V, so I suggest any LIPO you use should be configured to provide less than 6V.

Improve this answer
5
  • Yes, good idea. I could probably source one from an old phone.
    – Josiki
    Jul 3, 2017 at 8:44
  • @Josiki Will you also carry your old phone around to charge it?
    – Dmitry Grigoryev
    Jul 3, 2017 at 9:19
  • Phone batteries are unlikely to be LIPOs, probably standard Lithium cells. In either case as Dmitry Grigoryev suggests charging Lithium (including LIPO) batteries is not trivial. You need special chargers.
    – joan
    Jul 3, 2017 at 9:31
  • I haven't thought that far ahead to be honest. Charging it via my phone is a definite option. Although if that doesn't work, then maybe I should go for a different approach.
    – Josiki
    Jul 5, 2017 at 8:11
  • I accepted this as the answer, because my main concern was the weight. After getting a battery from an old phone (samsung s3) and checking that it powered the pi, I weighed it an it was around 20g, which is a lot lighter than the other options that were suggested.
    – Josiki
    Jul 9, 2017 at 19:54
0

two 3v cr2032 button cells (190-225mah) should do the trick, considering that it uses at most 230ma on peak load. So half an hour should be easily achievable. Do not forget to use a voltage regulator, as the pi does not like 6v. not sure about the power usage of a camera

Improve this answer
5
  • In fact the Pi itself will run quite happily on 6V, although HDMI and any USB devices or attached peripherals may not.
    – Milliways
    Jul 1, 2017 at 11:00
  • @Milliways Does the Pi Zero even use 5V? I would think that as long as the voltage regulator supports it then it would be fine. Do we know the tolerance on the 3V3 pin to just connect 2 CR2032 in parallel?
    – lights0123
    Jul 1, 2017 at 12:44
  • 1
    -1. A single CR2032 only provides 15 mA, you'll need 30 of them to run an RPi Zero.
    – Dmitry Grigoryev
    Jul 1, 2017 at 13:07
  • @lights0123 You should not ask questions in Comments, but the Foundation warns "Under no circumstances should a power source be connected to the 3.3V pins."
    – Milliways
    Jul 1, 2017 at 22:52
  • i tried putting two into it (via a micro usb cable that I had stripped apart), but it didn't seem like enough.
    – Josiki
    Jul 3, 2017 at 8:43
0

If the CR2032 button cells don't provide enough current, you could try 4 AAA batteries instead of AA batteries. That should reduce the weight some.

Improve this answer
2
  • Good idea! I will give it a try later :)
    – Josiki
    Jul 3, 2017 at 8:43
  • It works! But a phone battery is quite a bit lighter.
    – Josiki
    Jul 9, 2017 at 19:55
0

There are boost converters which can provide 5V 300 mA off a single AA battery (example). Of course, the battery won't last long, but it seems that's OK for you.

Improve this answer
3
  • That is cool! Although I don't know that it will give enough amps, I think the pi needs about 1A? Or am I wrong about that?
    – Josiki
    Jul 3, 2017 at 8:46
  • Depends on how you use it. If you plan to have Wifi and external devices connected, you may actually want to keep you 4 AA batteries.
    – Dmitry Grigoryev
    Jul 3, 2017 at 9:22
  • Yeah, I plan to use the wifi and (possibly) have a camera connected as well. So perhaps this is not the approach for me. I don't really want to buy something just to experiment with it.
    – Josiki
    Jul 5, 2017 at 8:12

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.