The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘Batteries’ Category

Low power timers for 6 hour on / 18 hours off in 24 hours time

Posted by jpluimers on 2023/04/14

Some notes, as in 2021, I started to see a lot of LED lights (often even LED string lights) being able to automatically do 6 hour on and 18 hour off in a 24 hour cycle to conserve battery usage and improve convenience.

Below are some links, as I might want to create such a circuit myself, maybe even with some solar charging. I’m especially interested to power these off 18650 Li-Ion batteries of which I wrote before (especially as you can easily salvage them from laptop or even e-bike battery packs).

Links via [Wayback/Archive] chip timer 6 hour per 24 hours – Google Search and [Wayback/Archive] microcontroller 6 hour on 18 off timer – Google Search:


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Posted in 18650, Batteries, Hardware, Li-Ion, LifeHacker, Power User | Leave a Comment »

Lii-500 Charger, and review

Posted by jpluimers on 2023/02/03

Via [Wayback/Archive] Jilles🏳️‍🌈 on Twitter: “Recycling old laptop batteries ” / Twitter, I ended up at this great in depth review [Wayback/Archive] Review of Charger LiitoKala Engineer Lii-500, including graphs of behaviour with various battery types and counts.

The site has many other reviews. Not just about [Wayback/Archive] Batteries and chargers (and a great overview at [Wayback/Archive] Round cell charger index). The main page is named [Wayback/Archive] Flashlight information, but shows links to lists of articles about batteries, chargers, multimeters, flashlights, projects and more.

So this is my list of things to try: [Wayback/Archive] Lii-500 Charger:

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Posted in Batteries, Li-Ion, LifeHacker, Power User | Leave a Comment »

Li-Ion BMS – Lithium-Ion Battery Management Systems and large battery packs

Posted by jpluimers on 2020/07/16

Just in case I want to really go off-grid: [WayBack] Li-Ion BMS – Lithium-Ion Battery Management Systems and large battery packs

It has a configuration selector module pointing to companies (even one in The Netherlands) that can help me out.

Via [WayBack] DIY Electric Car Forums – View Single Post – using 18650 cells to make 25kwh battery

Hopefully they are based on 18650 batteries:



Posted in 18650, Batteries, Hardware, Li-Ion, LifeHacker, Power User | Leave a Comment »

Building a rudimentary battery backup for your USB powered devices (IoT, Raspberry, etc)

Posted by jpluimers on 2020/07/14

Malcolm Lewis [WayBack] came with these interesting pastes for a rudimentary battery backup servicing USB powered devices:

Since both expired, here is some more elaboration with links:

From the picture linked above (full one at the bottom of the post): a switch is missing from the parts list (:

Note that this is only the hardware parts, and no measurements of the voltage from the Raspberry Pi. So it is a battery backup, not a UPS.

For a UPS kind of functionality, you need more hardware (measure voltage to assess when to safely shut down, reset circuitry for when power comes up), and software (so the devices can shutdown).


After IRC chatting with Lewis (see his [WayBack] profile), this is how they should be connected:

  1. USB charger:
    1. OUT connector type A of USB charger cable
  2. Connections to the TP4056 battery charger (a nice video on this is at Charging a Lithium 18650 Cell using the TP4056)
    1. IN mini/micro USB from connector type B of USB charger cable
    2. BAT pins B+ and B- to the + and – of the 18650 battery holder
    3. OUT pins +/- to your LM2577 IN pins+/-
  3. 18650 battery holder
    1. IN pins +/- to the TP4056 BAT pins +/-
    2. One or two 18650 batteries
    3. Note
    4. Most of the wired “parallel” 18650 dual battery holders on non-USA Amazon sites are in fact serial (you see that in the comments, or by watching the wiring carefully), so better buy an unwired one!
  4. Connections to the adjustable LM2577 step-up converter having a max current of 3A
    (get one *with* voltage meter, as voltage meteres themselves are about half the price of the LM2577!)

    1. IN pins from the TP4056 OUT pins
    2. Adjust to slightly above 5V before connecting anything else!
    3. OUT pins +/- to the red/black pins of a connector A stripped micro USB cable
  5. USB powered device (like Raspberry Pi)
    1. Micro USB connector: connector B of the USB cable coming out of LM2577

If you want to measure both voltage and current, then a combined piece like Voltmeter Amperemeter Dual Digital Volt Amp Meter Messgerät 100V 10A is very convenient. Most of these do not come with schematics, so here is one:


Parts from


There is a 6A module; though I’m not sure it is based on LM2577

Bad battery box example


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Posted in 18650, Batteries, Development, Hardware Development, Li-Ion, Power User | Leave a Comment »

18650 Battery shield V3(RaspberryPi&Arduino) from lspoplove on Tindie

Posted by jpluimers on 2020/03/04

As you know Tesla has thousands of 18650 batteries. The 18650 battery is a strong existence. So we made this 18650 battery shield for maker.


  • Battery protection(Over charge or Over discharge)
  • Micro USB port Input
  • Type-A USB Output
  • 0.5A current charging
  • 1 switch control USB output
  • 5~8V Input Voltage
  • 3V & 1A Output
  • 5V & 2A Output
  • LED indicate(Green means full,Red means charging)
  • 3V output port x3
  • 5V output port x3

Charging can only be done at 0.5A, so using it as a sort of UPS seems not possible, but an interesting device nonetheless.

The other products referenced from the same page are interesting too and will undoubtedly bring me some new ideas for some projects.

Source: [WayBack18650 Battery shield V3(RaspberryPi&Arduino) from lspoplove on Tindie




Posted in 18650, Arduino, Batteries, Development, ESP8266, Hardware Development, Li-Ion, Odroid, Power User, Raspberry Pi | Leave a Comment »

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