The actuator uses its status bit "Energy Storage" to indicate that its long-term operation has consumed more energy than it generated. The remaining charge level at this point is approximately 25%, which is why the device continues with full functionality while signaling a negative energy balance to the user. It is strongly recommended to regularly check the ES bit in order to recognize a discharge of the storage and to prevent its progression by suitable measures (e.g. Slow Harvesting outside of the standard operating times). If the energy storage continues to discharge and its voltage falls below a certain limit, then the device automatically goes into the state of Forced Heating.
Energy storage typical voltage values | Voltage [V] LTO |
Fully charged – for charge stop (bq25505 and USB) | 2.8 |
Fully charged – for indicator bit | 2.7 |
Normal operation | 2.4 typical (2.0 … 2.8) |
Energy storage bit set when below | 2.3 |
Forced Heating starts when below | 2.0 |
Forced Heating stops when above | 2.4 |
Microcontroller turning off all loads and its own power when below | 1.8 |
Microcontroller power-up (under hardware-control) when above | 2.37 |
Battery spec HTC1450 (capacity / charge stop / discharge stop) | >500mAh / 2.8V / 1.5V |
