1. At home cannot search star GPs by direct reception of U. S. GPS satellite signal work, need to see the sky outside the place to receive satellite signals, indoor can not receive!
2. Short battery time All car-mounted GPS batteries are not used for a long time. Because the car is a little smoke power, the designers think that there is no chance to take a long time to use battery standby, batteries only make standby, non-plug in the continuous use of power generally only 40 minutes ~1.5 hours, different models, different use, there will be a big difference. Need to note that the car ignition of the moment, the start-up current is very large, has the impact of burning car fuse the risk, preferably in the car start, do not plug in the cigarette smoke in the car charger, start and then connect.
3. Positioning not GPS normal plane positioning error within 10-20 meters, by the weather, such as the U. S. GPS policy and many factors, and sometimes even greater. If the map indicates that the location is not very accurate on the road, the cause may be bad signal caused delay error, may be the map data occasionally deviation, it may be the road is very wide, so it looks like GPS stabilized offset pavement.
4. Cannot search star or search star slow encounter cannot search star or search slow situation don't hurry, please change the place time and try again. Do not use one or two times, or a day or two to decide the good or bad GPS, because the satellite state is different every day, perhaps the same place, the morning signal full of lattice, but the evening signal almost.