Portable power source for Raspberry Pi

Germán Valero

Is there a reasonably priced external battery suitable for powering a Moodlebox for a few hours while travelling to a remote area with no stable AC, but with students with cell phones?

I was thinking about this example:
https://www.amazon.com/Cargador-capacidad-rendimiento-inteligente-dispositivo/dp/B07ZX22KJS/ref=sr_1_20_sspa?__mk_es_US=%C3%85M%C3%85%C5%BD%C3%95%C3%91&crid=1ON5EXASK4Y7M&dib=eyJ2IjoiMSJ9.nWWDb7ICQxcRK4slbnkuAozXexe2pw6QZHJ_FRYfhCIT2L6nF5ylv08qwCkBZyq58uweOTLS7HdIvV6zwDtwnqUvMi148_fv15AsCEEhHK4CtSWptnWEl3JVTu5h-kYF9ViD2KwoqjF4kXDLpdLCSqaobHtwhPph8KCCQqNcQaIqJAmZRzoUvQ0m8mDAR4vjFudeHNjwT_c8QOtZF4X3RcPAEqNXM1PVNYloM4FNTfQ.N8jMLNv6XG9vG7rKvDsLnokkxIOys0KG0zv3hSMuMm8&dib_tag=se&keywords=RASPBERRY%2BPI%2BEXTERNAL%2BBATTERY&qid=1761064505&sprefix=raspberry%2Bpi%2Bexternal%2Bbattery%2Caps%2C137&sr=8-20-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9idGY&th=1&language=en_US

Nicolas

You should choose a power bank with adequate output voltage and current, to prevent the Raspberry Pi undervoltage problems.

The standard voltage requirement is 5V, so ensure the power bank delivers this reliably. The recommended current depends on the model. Raspberry Pi 3 and 4 models require 2.5–3A. Choose a power bank with at least 3A output for compatibility with these models. Raspberry Pi 5 requires 5A, so for this model, you should ideally find a power bank with this current (and I don't know if such a device exists).

Germán Valero

Thanks for the very detailed information Nicolas.
Maybe for now the best solution for me would be to have a standard UPS supplying AC to the Power supply of the Raspberry.

Ralf Krause

Hey Germán,

you asked for a useful PowerBank. The parameters of the model you linked in your starting post are not useful. As Nicolas wrote a PowerBank must have 5 volt and 3 ampere. Your one shows a very big capacity 26800 mAh but has only 2.1 ampere on the first connector and 1 ampere on the second connector. Most PowerBanks with USB-A connectors have the limit 2.1 ampere because USB-A should not have more. If you look for PowerBanks with USB-C you will find products with 5 volt and 3 ampere.

I am using such a PowerBank for my MoodleBox with Raspberry Pi 3B (not 3B+). My PowerBank is really old but it still works … it looks exactly like your model but has only 20000 mAh. There is a MoodleBox course about the MoodleBox for outdoor excursions https://bildungsportal.magdeburg.de/moodle2/course/section.php?id=232 . The film shows a teachers workshop I made with the MoodleBox in the wood.

I also tested the MoodleBox with a PowerStation UPS with a 230 volt output for camping and outdoor. Yes, I could use the 230 volt connector with the Raspberry Pi power supply. The PowerStation UPS also had an USB-C port with 5 volt and 3 ampere.

Ralf

Germán Valero

Thanks a lot Ralf.

Now I am thinking about this item:

Anker Power Bank(PowerCore 10K), Compact Travel-Ready 10,000mAh Battery Pack with PowerIQ Charging Technology, 5V/3A High-Speed Charging for iPhone, iPad,and More(USB-C Input and Output(Black), 1pack)

For 26 US dollars + shipping...

Would this be a useful item for using a new MoodleBox with a Raspberry Pi 3?

I think it would be very nice if you (or Nicolas) could write a page about 'MoodleBox on the go' in https://moodlebox.net/es/help/

Germán Valero

A more robust (more expensve) power bank:

https://www.amazon.com/gp/product/B0BY82VVCQ/ref=ox_sc_act_title_1?smid=AEFQAQZNFUFJX&psc=1

Ratna

Germán Valero Then there is the opposite direction. MoodleBox runs even on a RPi Zero 2 W. In terms of energy saving and response time, I had great experience with RPi 3 A+. Of course both don't have ethernet. But MoodleBox has two wireless interfaces (one virtual). So one could be connected to an upstream wireless router/access point/mobile phone when the other is serving the local devices, mobile devices or laptops. From memory, I could run a class for 2-3 hours on a 5000 mAh power bank. May be I'm wrong. Don't have the 3 A+ anymore to confirm.

Germán Valero

I will be getting a kill-a-watt inexpensive device for measuring the actual Amperes being used by my MoodleBox serving a few users while I add plugins and, with that information, I will budget the least expensive power bank that can maintain that Amperage.

Nicolas

Germán Valero measuring the actual Amperes being used by my MoodleBox

I find this a good strategy.

Ratna

Germán Valero I too need to get a power consumption meter.

BTW, the other side of the coin I was talking about is to find out which R Pi model powers your application sufficiently - "older" the model ( 5, 4 or 3 or even 2 W), longer it will churn from a given power bank.

Ralf Krause

Germán Valero
Hey Germán,
have you received the measuring device yet? The one you mentioned also measures the losses of the power supply. If you want to measure the actual power consumption of the Raspberry Pi drawn from the power bank, you'll need a USB meter like this one: https://www.amazon.com/dp/B0B1J5JL6Q/

This measuring device plugs into the output of the power bank. Then the USB cable to the Raspberry Pi plugs into the output of the measuring device. Yes, I have such a device on my wish list because your idea intrigued me.

Best regards, Ralf