UPS for micro-controller

Hello everybody,

In yesterday's post we briefly introduced our new power bank module, which is ideal for the operation of microcontrollers, since the module does not, as is now the norm, set the supply to save energy with low power consumption, but continues to supply the necessary voltage.

Another advantage of the module is that the module switches the power supply "to battery operation" during operation. This predestines the module as Uuninterruptible StromVsupply, i.e. UPS (UPS) for Arduinos or ESPs.


The project presented here is an experimental setup. Working with mains voltage is reserved for electricians in Germany.

While Arduinos are quite unproblematic in terms of power supply, the ESP processors have significantly higher demands. Operation with chargers from mobile phones is possible, but must be checked urgently in practice as many chargers do not provide the electricity as quickly as the ESPs would like.

For today's project we need:


So we start with the power supply:

This power supply has served us loyally on many projects. The specified 5V 1.5A are actually provided and the voltage under load is relatively stable. A simple and safe solution. In contrast to this:

Alternatively, you can also design your own circuit with our mini power supplies, if you are one of the lucky people who can call themselves a certified electrician. Please pay particular attention here to the prescribed safeguards, touch-proof terminals, air gap, etc.

For the reasons mentioned above, the board shown in the picture is NOT available from us, only the USB breakout. A laboratory power supply is also suitable for an experimental setup.

In the next step we wired a 18650 Li-Ion battery, this will be charged with the existing power supply. The charge controller protects the battery and switches off in time when the voltage is reached, so that the battery can neither be overcharged nor deeply discharged. When using as a UPS, you should make sure to discharge the battery regularly to increase the service life.


The pins provided on the charging module are marked with Bat + and Bat- as shown in the next picture:

So most of the work is done. In the next step, we just have to plug in the USB cable. Since our plugs are quite thick, I had to carefully bend the two USB sockets:

I then programmed an ESP32-LoRa board with a WiFi and Lora sketch to test a failover.



Have fun experimenting with our new module and until the next post :)






For arduinoProjects for beginnersPower supply


Ralph Schraven

Ralph Schraven

Hallo, verrückte Frage vielleicht. Wäre es möglich, mehrere Module zu daisy-chainen? Also z. B. 2 Boards mit Akku „hintereinander“ zu betreiben und damit (abzüglich Verlust) die doppelte Kapazität zu bekommen? Wenn beide voll sind, müsste dann das „hintere“ Modul Strom geben, bis es abschaltet und dann das vordere. Im Moment verwende wir eine 2-Akku-Schaltung mit Load-Balancing etc. – sicher energiesparender, aber recht aufwändige eigene Platine. Ein Akku doppelter Kapazität an einem Modul wäre wg. Bauform keine Lösung.





Ich suche so etwas für den Einsatz mit einem RasPi 3
Der braucht aber viel mehr Strom. Ich denke, 2-2,5 A sollten da schon gehen.
Gibt’s da auch etwas, oder muss ich mich mit 800 mA zufrieden geben?

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