There are different kinds of dog silencers on the market concerning battery usage. Some models are rechargeable; thus, there is no need for constant purchasing of batteries. The other model of dog silencers uses changeable batteries which often operate for up to a week before they must be changed. The need to change your batteries is primarily dependent on how often you use your device for training. If you train your dog a lot, you will have to change it every week, but as the training sessions reduce, your batteries may last longer, with a lifespan of two to four weeks. Another determinant of battery lifespan is the weather, regularity of device activation, and battery quality.\r