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I'm creating a project using the Raspberry Pi Zero W and a Pi Cam to take pictures remotely.

Think deer camera in the woods. I need this to be battery powered and last at least a week.

Is this possible? What is the best battery setup for a job like this? I'm looking at the LiPo batteries from Adafruit. Battery/power is my my main concern at the moment, the rest I have a grasp on.

How do you hook up a LiPo battery (like this) to power a Pi Zero?

If anyone has a tutorial on doing something like I'm asking, that would be very helpful.

UPDATE

So I plan on taking a photo every hour on the hour, so 24 photos per day. Let's say average temperature will be around 50-60 degrees fahrenheit.

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    Any answers will be dependent on how much usage the thing's actually going to get during the week, and on the temperatures you envisage using it at (battery chemistries behave differently at certain temperatures). Can you edit your question to include a ballpark guesstimate of how much you imagine shooting, and approximately where you are in the world? – goobering Mar 13 '17 at 14:03
  • @goobering updated. – Corey Mar 13 '17 at 14:13
  • Is the plan to make it motion activated (more battery as you need to monitor continually for things moving), or is it genuinely 1 shot per hour? – goobering Mar 13 '17 at 14:17
  • @goobering Right now I just plan on taking a photo once per hour on the hour. Basically creating a timelapse. It may actually be less as I do not need to capture photos of darkness, so maybe more like 12 hours. But for the sake of argument, I just want to plan for at least 24 photos per day. – Corey Mar 13 '17 at 14:20
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If you don't really need the WiFi capabilities you'd be better off using a 'standard' Pi Zero, as opposed to the Pi Zero W. According to these figures on raspi.tv the Zero uses around 20mA less on average - not a huge saving, but significant if you're running on batteries. Whatever solution you use, the battery's likely to be a hell of a lot bigger than the one you've linked to in your question - Pis are not particularly easy on the juice!

Using the raspi.tv figures linked above, if you run a Pi Zero W 24/7 for the duration (the simplest solution) you're looking at something like:

Per day:

230 mA x 0.17 hours (10 minutes total taking photos per day)
120 mA x 23.83 hours

= 39.1 mAh + 2859.6 mAh
= 2898.7 mAh

Per week:

2898.7 mAh x 7 = 20290.9 mAh

At the time of writing, Anker manufacture a 26800mAh power supply that should be large enough to run the whole thing for a little over a week. Your mileage with this may vary depending on temperature and longer term battery fatigue. This approach is as easy as it gets - just charge the battery, plug the Pi in, come back at the end of the week and take it away. No additional effort required.

For a more complicated approach you'd be looking to wake up and shut down the Pi at fixed intervals. There's no way to do this without using an additional microcontroller - something somewhere has to be on all the time to maintain a clock. There are some suggestions in this thread already - from those I would recommend looking at the Witty Pi add-on board (designed specifically for the job), or just using an external timer circuit and a relay to flip power on and off when you need it. I'd imagine that would get you down to something like 10 minutes of Pi uptime per hour (couple of minutes to boot, couple to shoot, couple to shut down, couple for safety margin), plus the 24/7 power consumption of your external circuit (if it doesn't have its own battery). The Witty Pi claims 1 mA of current use in normal operation, which would get you towards something along the lines of:

Per day:

24 events x 230mA x 0.03 hours (2 minutes-ish) = 165.6 mAh
24 events x 120mA x 0.13 hours (8 minutes-ish) = 374.4 mAh
1 mAh x 24 hours = 24 mAh

165.6 + 374.4 + 24 = 564 mAh

Per week:

564 mAh x 7 days = 3948 mAh

That's obviously a heck of a lot less power used, but there are a lot more potential points of failure there.

Whatever approach you finish up using, I would strongly recommend sticking with the Pi's micro-USB power input over connecting a battery directly to the 5V rail. The micro-USB connection offers a lot more electrical protection, reducing the chances that your Pi will burn if anything weird happens. It may cost a little more for a pre-built charger pack but you significantly reduce the likelihood that you'll destroy your Pi during normal operation.

  • So I can just plug a battery pack like the Anker one you linked to, straight to the USB power, and it will turn on? For some reason I thought there was more to be done to get a Pi running on battery power. – Corey Mar 13 '17 at 19:44
  • Also, I'm guessing it would require a pretty big solar panel to run this off of solar power? – Corey Mar 13 '17 at 19:46
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    There's no on/off switch on a Pi - if it gets 5V-ish to either the micro USB power socket or the 5V/ground pins then it's on until you unplug it again. The micro USB socket's attached to some circuitry that protects the board a little, while the pins are not. As for solar power, I'm not too knowledgeable on the amperage-per-square-metre you might expect. As long as it spits out 5V and about 250mA consistently it'll work, otherwise you're looking at brown outs and random shutdowns. – goobering Mar 13 '17 at 19:49

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