Using capacitors to fix power dips?

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1

I am trying to power a Pi Zero and Inky Impression 13” with a 1S li-po. Since I am new to this I am using ChatGPT quite extensively.

Yesterday I was finding that the Pi was resetting when the Inky Impression was updating, presumably because the power draw was dropping the voltage below what the Pi needs. (Is this called a brown out?)

When I asked ChatGPT about this it suggested adding two capacitors, a 470–1000 µF electrolytic and a 10–47 µF ceramic in parallel, very close to the Pi.

After a bit of internet sleuthing I increased my power booster output from 5v to 5.2v which appears to have fixed the issue, but I am still wondering whether ChatGPT’s capacitor advice is good or not, since I have not found anyone else doing this on the internet.

Most of the advice seems to be to get a better power source (an official USB wall wart or an Adafruit 1000 power booster).

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Using capacitors is common for buffering transient voltage spikes/dips that occur if the load suddenly changes. Using parallel capacitors with different values filter out different frequencies. If you take a look at some of the schematics from Pimoroni you can even see that some circuits use a whole battery of capacitors.

If you look at the Pi Zero, you will find a capacitor near the power-plug. If you don’t use the power plug, but feed the power directly into the 5V pins, you might need to provide your own caps. But be aware that caps won’t solve the problem if your power source does not provide a stable voltage. So your solution to increase the output voltage is certainly the right thing to do.

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