In the last few weeks we had been testing circuits for a newer version. Problems like battery-level detection and graceful shutdown will be solved.
To achieve these goals, we still need i2C port on gpio. Therefore we are redesigning a micro pogopin to fit pi zeros with and without gpio headers.
New dual chip design will avoid voltage drop when switching from USB charge to battery power, which will cause a pi reboot.
Even they look a bit weird right now, they are our hopes of next generation product : )