The collar is equipped with a 3-cell lithium ion battery (3.6 V, 9,750 mAh, 35.1 Wh) connected to 2 solar cell panels. The GPS represents the largest proportion of power consumption. As described, the intensity of the GPS depends on the distance to the pasture boundary. The more the collar is registered as having a sufficient distance from the grazing pasture boundary, the lower is the power consumption.
Power savings are highest when the goat is more than 30 metres inside the grazing pasture. Therefore, knowledge of where the goats prefer to stay and rest should be taken into consideration with the placement of the grazing boundaries. In all circumstances, grazing boundaries should be set well outside sheds or barns and at a minimum of 30 metres. If it is necessary to set a boundary closer to an established resting place, a beacon must be used, preferably in combination with a physical fence. If the grazing pasture borders the sea, river, or other natural barrier that in any case the goats cannot cross, the grazing boundary should be set more than 30 metres outside of these to achieve reduced power consumption.
As goats have different behaviours, it is also expected that battery life will vary from collar to collar:
- Goats which are often located near the grazing boundaries will have higher power consumptions than goats that stay further away from the boundaries.
- Collars worn by goats that rest more will also have longer battery lives than those worn by goats that move around more. This is due to the activation of ‘sleep’ mode, which is triggered by a sufficiently low reading from the accelerometer.
- Charging via the solar cells is heavily dependent on whether they are exposed to direct sunlight. Therefore, better charging is achieved if the goats are on open terrain compared to if they stay in forested and scrubby areas.
Charging a battery takes 8 – 10 hours. When the battery is fully charged, the green circle is constantly lit.