Fubarino Contest: Battery Capacity Tester

fubarino-contest-battery-capacity-tester

Here’s a project that we sadly let slip through the cracks a couple of years ago. Luckily [Brian] dusted it off and added an Easter Egg to the firmware in order to include it in the Fubarino Contest. The device is a rechargeable battery capacity tester. It discharges NiMH or NiCad batteries through a load resistor at about 1 Watt. [Brian] includes a discussion in his write-up about the hardware’s inability to work with 14500 Li-Ion cells. He includes enough info for you to figure out how to make changes to the circuit if you want to enable this option.

There is a MOSFET for switching each of the three battery positions. The ATmega168 takes readings from the cells once per second. It displays status information on a Nokia 5510 cellphone screen. This is where he chose to inject the Hackaday URL. When a cell’s discharge is complete, the image above scrolls onto the screen and remains there for a short time. See for yourself after the break.


This is an entry in the Fubarino Contest. Submit your entry before 12/19/13 for a chance at one of the 20 Fubarino SD boards which Microchip has put up as prizes!

5 thoughts on “Fubarino Contest: Battery Capacity Tester

  1. I built one of these enclosure and all last spring for a senior project. The code is clean and the circuit well designed, still use it today to gauge how much life a rechargeable has before it is useless.

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