This paper presents a multi-channel, multi-technique electrochemical instrument with the size, power and performance for portable applications such as point-of-care diagnosis, wearable sensing, and toxic chemical detection. Composed of a custom analog interface and a commercial low-power microcontroller, the portable instrument is capable of dynamically adapting to a wide input current range exhibited by many electrode/sensor types and observed in the transient response of many electrochemical techniques. The instrument can generate several standard electrochemical stimulus waveforms or an arbitrary waveform, independently and in parallel on multiple channels, while streaming measurement results to a USB host. The portable instrument was tested across multiple conditions against a commercial benchtop electrochemical instrument in a potassium ferricyanide solution. The maximum normalized root mean square difference between test results and the commercial instrument is less than 2%, cementing system robustness.