The Smart Remote 3 product example is powered by two AA batteries.
The batteries can be alkaline (2 × 1.5 V) or rechargeable NiMH (2 × 1.2 V) batteries. The battery circuit has a protection diode to avoid reverse current if the board is powered elsewhere. In parallel with the battery there is a connector (P3) that can be used for supply during development. See Battery schematic.
Figure 1. Battery schematic
There is a power switch on the Smart Remote 3 that is connected to most of the circuits. The nRF chip controls the two transistors. See Power on/off switch schematic. The low-power accelerometer is always powered.
Figure 2. Power on/off switch schematic
