In difference to the original Turtle Rover battery I run a custom battery pack in a 6S3P configuration of Samsung 18650-35E cells. That’s 22.2V/10.2Ah in total. The brand new, yet to be released, Texas Instruments BQ40Z80, a 2 to 7 series battery pack manager with impedance track gas gauge, takes care of the entire pack. Its protection and balancing features guarantee safe handling of this energy source. The SMBus interface allows readout and indication of all battery lifetime parameters in the Rovers mission control software.
The BQ40Z80 requires several charge and discharge cycles to learn battery chemistry, internal resistance, capacity etc. Since these cycles are time consuming and several parameters and flags must be monitored, I created a C# software that semi- or fully automates this process with help of a simple relay jig. It’s open source and can be found on Github. However, the software might be obsolete as soon as the BQ40Z80 is fully supported in TI BQStudio software.