Hackaday Prize Entry: A PCB To Emulate Coin Cells

The Coin Cell Emulator CR2016/CR2032 by [bobricius] homes in on a problem some hardware developers don’t realize they have: when working on hardware powered by the near-ubiquitous CR2016 or CR2032 format 3V coin cells, power can be a bit troublesome. Either the device is kept fed with coin cells as needed during development, or the developer installs some breakout wires to provide power from a more convenient source.

[bobricius]’s solution to all this is a small PCB designed to be inserted into most coin cell holders just like the cell itself. It integrates a micro USB connector with a 3V regulator for using USB as an external power source. The board also provides points for attaching alligator clips, should one wish to conveniently measure current consumption. It’s a tool with a purpose, and cleverly uses the physical shape of the PCB itself as an integral part of the function, much like another of [bobricius]’s projects: the Charlieplexed 7-segment LED display.

41 thoughts on “Hackaday Prize Entry: A PCB To Emulate Coin Cells

    1. It ain’t over engineered enough, It needs to be powered from a nuclear power plant with 12MW dumped into a massive liquid hydrogen cooled current shunt that has 3v across it worked out from Ohms law to get the correct shunt impedance.

    2. You must not work in the toy industry. :) I’ve done four projects running off of coin cells this year, so far. We were ordering LR44s 250 at a time, almost every month, for a while. While this wouldn’t work for every step of the development process, as we do need to account for the current limits of the actual cells, this would save us /tons/ of money during the bringup stages.

  1. It is useful, but I would add it needs an pluggable/extensive/whatever for the part of coin cell connector. As in, an adapter so this can be connected to other form factor sockets, like those in pc motherboards.

  2. Well, I have no opinion about this thing but a big ole “up your nose with a rubber hose” to the jerks that somehow thought soldering a battery in place was a practical option for something that needed to be changed.

  3. I really like the idea, but I wonder if this does miss the boat on designing how battery failure conditions are handled. There’s an opportunity to simulate different power conditions with this emulator that doesn’t exit with a normal coin battery.
    Value added opportunity!

    1. Its only the cheap ones that do that. Poor design. A Mitutoyo will last quite a long time before batteries need replacement. It just costs more for initial purchase. For my needs the cheap pair worked well but it was a hassle for the batteries to be dead every time I needed it, so i spent the money on the Mitutoyo.

  4. This only “emulates” voltage, and it is target for development. The same thing can be achieved by a pair of wires as mentioned before.

    A true emulation should consider the discharge voltage curve and the impedance model for the desired battery.

    If the goal is to save the time that takes to solder 2 wires, well done then.

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