Battery powered Raspberry Pi

To be able to run my Pi at any location I built a battery powered power supply for it.
Its base is a 8x battery holder (8x 1.2V-1.5V = 9.6V-12V) so it is guaranteed to provide stable 5V+.
To get down to the 5V needed by the Pi I am using a switching BEC (SBEC) which is a very efficient power regulator. The one I used can be found here.




For a maximum of flexibility I decided to use a USB Type A plug so that this power supply could supply any USB based device with power. I even can use it to charge my mobile phone.
As shown the Pi is connected using a ultra short USB Type A -> Mini USB cable.


The power plug is assembled with standard Eneloop rechargeables of the 3th generation so the powery supply delivers 8x 2000 mAh = 16.000 mAh.

This power supply delivers nearly 4000 mAh (see comments below)

My first test for the battery lifetime was disappointed:
I did connect to the Pi using ssh and printed out the uptime in a while loop with a sleep of one second.
The Pi did stop running after 7h 49m.

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2 Responses to Battery powered Raspberry Pi

  1. Valikika says:

    8x 2000 mAh = 16.000 mAh – That’s totally wrong. Your setup can deliver exactly 2000 mAh.
    If you put all batteries in parallel though, then you would have had 1.2V with 16.000 mAh. 😉

    • Peter Fichtner says:

      You’re right: 8×2000 mAh is wrong but 2000 mAh at all should be wrong too. Since 8 x 1,2V are 9.6V and the SBEC provides 5V (nearly the half of the 9.2V) out of them it should be twice the value of 2000. 3840 mAh to be exact, right?

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