Right portable power supply for Arduino project

I am very new to Arduino and helping some school-age kids with a project requiring portable power. They would like the power to be rechargeable so they can easily recharge as required and they want it to be relatively simple so they can focus on the main project. The project involves the following components:

I’ve done some research so just want to double-check before I order the extra things we need.

If I assume that the Uno draws < ~50mA + Bluetooth shield (tech spec says 50mA) and Pixy2 (tech spec says ~140mA), then I think that 0.5A will be enough for the project.

Q: Have I got this right?

Looking through various options, it appears one good option is the Adafruit PowerBoost 500 Charger (https://core-electronics.com.au/powerboost-500-charger-rechargeable-5v-lipo-usb-boost-at-500ma.html) along with an appropriate 3.7V LiPo battery (e.g. https://core-electronics.com.au/polymer-lithium-ion-battery-2000mah-38459.html) to give ~4 hours of usage before recharge (they only really need it to run for an hour or so but this gives enough headroom without being excessive). The 5V output from the PowerBoost can be connected to the USB on the Uno and the 0.5A will be sufficient to power everything they need. The PowerBoost is almost perfect out-of-the-box but I understand that the USB port requires some soldering plus if they want a switch (e.g. https://core-electronics.com.au/breadboard-friendly-spdt-slide-switch.html), this will also need some soldering (new skill to learn!)

Q: Do you agree that the PowerBoost would be appropriate for this project? Do you have another suggestion that would suit better with regards to recharging and simplicity requirements?

Finally, I note that there is a PowerBoost 1000 Charger which is slightly more expensive but can deliver 1A. I understand that the Uno’s USB port can accept up to 1A so, although we don’t need more than 0.5A currently (sorry, bad pun), I wonder whether this might give more flexibility in the future.

Q: Am I right that the only downside in our case for getting the PowerBoost 1000 vs 500 would be the extra $5 cost i.e. the power draw on the battery would be the same as regardless of capacity, it would only draw the mA that are needed by the components?

Q1. Yes that battery supply should work well for what you want.

Q2 and 3. The 1000mA will give you more flexibility for the future and the devices will only draw what they need from the supply. There are no downsides to going to the bigger supply aside from the cost.


Thanks for the reply. Good to know that I understood it well enough that you could just confirm what I thought.

If you want to go for an option without any soldering you could also power the Arduino from most USB Battery Packs that you would use to charge your phone.


I am using a jaycar 5000maH battery pack for $15 odd now, though it was $50 when I got it. The nice thing about this is that when the pi shuts down (using software) , the battery pack will also turn off after a moment or two. To power on, just touch the button on the usb pack.

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