🎉We can now proudly present the winners of the TAPAS Community Challenge 2018! 🎉
Congratulations to Team "Wireless Charging" (idea 56). We are really excited for all finalists and a really big thank you to all participants for your interest in this challenge!

We got over 200 submissions! 65 ideas got one or more TAPAS boards, 10 submissions were presentation-ready.
And now we have 5 finalists! YEAH 😃 The finalist's idea numbers were 40, 56, 68, 212 and 213.
What's next?
We are now preparing the next steps for you, the community. Please stay tuned!
We are working on a forum and a separate webpage. If you have any question please don't hesitate to contact us via email!

Automatic Battery Test System to evaluate Second-Life Possibilities


My application idea for the TAPAS board is about batteries, especially used Li-Ion cells, with many cycles on them. The TAPAS board will be part of a fully automated test system to analyses the performance characteristics of the Li-Ion cells. Knowing these characteristics, which are different compared to a new cell, is important to evaluate the possible second-life use cases of older batteries. The Raspberry Pi will monitor and control the test system and host a digital platform to analyse the data.

The main performance characteristics are the internal resistance. the capacity and the self-discharge of the cell. The capacity can be measured during charge and discharge cycles. Discharging at different C-Ratings (1-10C)  can give a realistic results on the real capacity for different load situations.

The internal resistance can be determined using different methods. However the internal resistance also depends on the method used and thus several methods will be implemented using the TAPAS board - the current step method and more important electrochemical impedance spectroscopy (EIS). The fast switching possible with the TAPAS board is perfect to implement EIS as i needs a signal in the kilohertz range. 

The self discharge will be monitored while the cells are waiting to be tested as well as afterwards

Test System

A system made with the TAPAS boards could control the charging and discharging very accurately up to the high frequencies of several hundred kilohertz need for the EIS

In addition to the TAPAS boards, a data acquisition board based on a 24bit ADC (TI ADS1248) called TeensyDAQ , which is currently being test, is part of the system. Its function is to supervise the cells temperature and measure very accurately the voltage during the tests. More about this project: https://hackaday.io/project/158060-teensydaq

An overview schematic of the automatic test system is shown in the attached picture. The use two TAPAS boards would reduce the testing time and allow for different test setups at the same time. The Li-Ion cells, 3 at the same time, are loaded on to a carrier which is loaded into a hopper. A linear motions system transports the carrier with the cells from the input hopper to the first TAPAS board, then to the next and places it into the output hopper. 

Business Idea

This first test system would also help to evaluated the business case of reusing li-ion batteries by generating first real-world test data and and estimating the effort that would be needed for large scale battery testing.

  • Jonathan Gräßer
  • May 28 2018
  • May 30, 2018

    Admin Response

    this idea gets two TAPAS dev kits

  • Susanne Forster commented
    May 29, 2018 14:10

     Hey Raffaello, 

    thanks for your submission. Great idea!
    We want to provide you 2 TAPAS boards.
    One of my colleagues will message you shortly.

    Susanne @ TAPAS team

  • Susanne Forster commented
    May 29, 2018 15:21

    Oh, i am sorry for the name confusion Jonathan :-)

  • Jonathan Gräßer commented
    May 29, 2018 17:15

    Thank you very much Susanne and the rest of the TAPAS team.


  • Admin
    Nora Schille (TAPAS team) commented
    June 04, 2018 14:41

    Hey Jonathan, 

    I hope the boards arrive soon.
    Here is just a friendly reminder that submission deadline for your presentation is on 24th of June.
    We are really excited to see your progress! 
    Please post the progress within your idea board submission.
    PS: We want to do a community call with you! Please use our doodle to find a date which fits best for you. :-)

    Nora @ TAPAS Team

  • Jacqueline Hofmann commented
    June 20, 2018 12:58

     Hi Jonathan,

    Don't forget that the submission deadline for your presentation is on 24th of June! We are already curious to see the results of your project :-) Keep in mind that you still have time to work on the implementation of your idea after the submission!

    Please post your project visualization and all related documents within your idea board entry :-)


    Jacqueline @ TAPAS Team

  • Jonathan Gräßer commented
    July 17, 2018 23:18

    Hello Tapas Team,

    I hope you are still reading here ;) 

    Its cool to see the winner projects, they have earned it! I had unfortunately my exam period in June and couldn't work on my entry, but i will continue anyways now :) 

    I was wondering if there are plans for a forum where users can exchange about their experiences and help each other with difficulties. The Github might be the easiest option. Maybe some directions from you to all users could help to form a community. 



  • Admin
    Nora Schille (TAPAS team) commented
    July 30, 2018 12:32

    Hey Jonathan,

    the last weeks preparing for the final conference kept us really busy!
    I'm glad to hear that you liked the finalist's idea.

    We are currently working on set-up a forum for the community asap and also update you (and the community) about the latest news of TAPAS.
    I hope can present something really fast. Please stay tuned (also via our social media).

    Keep doing awesome! :-)
    Nora @ TAPAS Team

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