Hello, not much, because it has a very low quiescent current!
Third: more advanced. Just send text messages: JT or JT# to the device's phone number, the device back to you pull. So do not open to show. Such as Wei Tong star, smart star brand is this way.These have a problem, it is necessary to use the local card, or roaming calls expensive.
The second: binding some devices are bound to bind the phone number to listen to the sound. But to spend six yuan to open the display, the device can know who is calling, is bound to the number, it is connected, you can hear. This brand is the city walk this way.
There are a number of GPS locator is a remote sound, there are three ways to listen.The first is that you call the phone number on the device, you can automatically answer, there is a downside, that is, advertisers mistakenly call in, you can hear the sound of the car. Some cottage goods in order to save the cost of development, use this.
