As we mentioned earlier, GPS trailer tracking devices are usually powered through an integrated battery. This may be a rechargeable unit that charges when the trailer is hitched to a vehicle, or it may simply be a unit with an extended battery life. This latter option is the more common solution. A tracker’s battery life can vary from model to model. While some have a battery life of up to three years, some high-end models claim a battery life of up to 10 years. Like many things, battery life is dependent on several factors – including the strength of the GPS signal emitted by the tracker, and the number of messages it transmits. In order to maximise battery life, these factors can be limited. Some devices can be configured to provide just one message per day when the trailer is stationary, and transmit data at a rate ranging from once every 15 minutes to once every two hours when the trailer is in motion. Oh, and another thing – it goes without saying that non-rechargeable batteries need to be replaced well in advance of becoming discharged. To assist with this requirement, some battery-powered trackers can report on the current status of their battery.