PowerBoost 1000 5V with a 3.7v LiIon/LiPoly battery

Question

I am very new to electronical components, and I am not sure if I can do the following:

I am planning to start a project where a RPi Zero W would record 720p and/or 1080p videos (60fps ideally, else 30fps will be enough). That RPi would be powered by a LiIon/LiPoly battery, however I am not quite sure how to read the values before buying the components.

From that I have multiple questions. Let's take the PowerBoost 1000 for example. It claims the RPi can be powered by any 3.7V LiIon/LiPoly battery with it.

• On that thing, I am not quite sure how a 3.7V battery can be "boosted" to 5V?

• It is written USB Boost @1A on the title, but the description is 2A internal switch (~2.5A peak limiting) means you can get 1000mA+ from a 3.7V LiPoly/LiIon battery. Just make sure your battery can handle it!. What does the internal switch mean, and how to use that switch?

• A 2A power source is recommended for a RPi. Is that PowerBoost would be sufficient? Why? Would the 500 version be enough?

• I read about wrong polarity being used on those 3.7V batteries. What does it mean exactly and how to prevent using the wrong components?

• A part from the charging ability, what difference is there with the Pimoroni LiPo SHIM?

Answer 1

I'd test first if the Raspberry PI zero is even capable to handle 1080p.

The Raspberry PI Zero W with fully loaded CPU and some Wifi utilization is taking about 200-250 milliamps, but there is nothing else. Camera and storage will raise power consumption significantly.

• About boosting battery voltage to the 5V - Boost converter - one of the modes of switching power supplys is basically working in two phases:

  1. Switch is closed and it's storing energy into the inductor
  2. Switch gets openned and the energy is released through rectifying diode into capacitor (it's another storage for the energy). The voltage generated by inductance is also added to the input voltage.

You should do some research on it. It also answers the second question about switches.

• Third point depends only on peripherals connected to it.

• Polarity - You just have to be extra carefull how do you connect it. Maybe some ready to use Powerbank would be better way for you as you don't have any experience with electronics