G+_Jason Eckelstafer Posted June 8, 2016 Share Posted June 8, 2016 Need someone who's good at calculating power consumption rates. How long would a Pi3 running RetroPie last if I were to use this battery pack (16750mAh)? Would it simply be 16.750/2.4=6.98H? http://www.amazon.com/External-RAVPower-16750mAh-Portable-Technology/dp/B00MQSMEEE http://www.amazon.com/External-RAVPower-16750mAh-Portable-Technology/dp/B00MQSMEEE Link to comment Share on other sites More sharing options...
G+_Travis Hershberger Posted June 8, 2016 Share Posted June 8, 2016 Considering that a Pi doesn't really do anything without additional sensors/displays/etc, probably not that long. You'd have to measure actual power drawn by the Pi while it's operating to get a better idea of how long a battery would power it for. Link to comment Share on other sites More sharing options...
G+_Jason Eckelstafer Posted June 8, 2016 Author Share Posted June 8, 2016 My Pi3 will be running RetroPie to a self powered monitor. Only thing to power would be the onboard Bluetooth receiver so basically stock I think. But I agree, I would love to figure out the actual draw. I don't have a working meter right now. Link to comment Share on other sites More sharing options...
G+_Eddie Foy Posted June 8, 2016 Share Posted June 8, 2016 Pi2 with a Alpha 1000mw Wifi adapter running reaver full time I was getting about 36 hours on a 7Ah SLA. That 16Kmah? I question. Those cigarette-pack sized batteries have very sketchy and boastful ratings. (they should come with a packet of salt in the box) Link to comment Share on other sites More sharing options...
G+_Dan Hockey Posted June 9, 2016 Share Posted June 9, 2016 I found out the hard way that the PI3 is sensitive to low voltage when powered via usb. First find a usb power analyzer and test you power supplies. You will be really lucky if you find a psu that puts out 5 volts when powering your pi. Then there's the problem of trying to find usb cables that can handle the amperage. If your psu doesn't supply something close to 5v you will see a rainbow colored square in the upper right corner of your display. Some where around 4.8v the pi shuts off wifi, blue tooth, and Ethernet. When the voltage dips past that during boot up it shuts that off and there is no way that I know to bring it back. The official rpi psu operates at 5.1v. Link to comment Share on other sites More sharing options...
G+_Eddie Foy Posted June 9, 2016 Share Posted June 9, 2016 low voltage cutout relay. Latching relay with an hi-efficency op-amp and voltage ref. Could also add in a secondary for a trigger to do a proper Pi shutdown before the relay kicks off. Link to comment Share on other sites More sharing options...
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