Building a battery R&D lab is expensive.  One of the largest capital costs is battery cyclers.  High accuracy battery cyclers can cost >$4000/channel.  A well-equipped lab requires hundreds of channels, costing hundreds of thousands of dollars.  These costs are prohibitive, which ultimately slows the discovery of new battery chemistries. 

To reduce the cost of performing research and accelerate the discovery of new materials a low cost battery cycler has been created.  A galvanostatic battery cycling daughter board has been designed that plugs directly into a Raspberry Pi (Figure 1).  The Raspberry Pi battery cycler behaves similar to commercially available cyclers (Figure 2).  The user can define: upper/lower cut off voltage, constant current charge/discharge, data save intervals and cycle number.  At scale, the unit cost is <$100/channel.  Substantially cheaper than comparable battery cycling hardware. 

The circuit was tested by cycling a commercial coin cell on the Raspberry Pi battery cycling hardware, then switching the cell to a commercial Maccor 4000 channel and comparing the results.  Data in Figure 2 shows that the performance of the Raspberry Pi circuit is very similar to a Maccor 4000.  

The Raspberry Pi battery cycling system has the following characteristics:

• Low cost (< $100/channel)

• Built in temperature sensors

• Modular (all channels are independent)

• Record data vs. time (text files) and ‘push’ data to a central server in real time

• Compact and headless operation (operates over wifi, no mouse/keyboard/monitor required)

• Galvanostatic charge/discharge cycling: ±5 V range, 1 uA – 10 mA, up to 0.1% accuracy

• Auxiliary voltage measurements (e.g. temperature, pressure, humidity, strain, volume) synchronized with cycling data