1, whether or not there is a battery, charging IC will increase the cost of $0.5, but it will make the battery in the trickle, constant current, constant voltage charging conditions, full automatically cut off the charging circuit, the damage to the battery is the least, not easy to cause battery damage. ERY boiler drum overheating, explosion and other accidents. The cost saving hardware does not need to charge the IC, but instead uses a current limiting resistor to connect the 4.xx voltage directly to the battery. The battery will always be in current-limited charging state. Battery life will be greatly reduced. Prone to bulge, explosion and other accidents. It's easy to have an accident when the phone is plugged into the charger all the time.
2. No matter whether the battery itself has overcurrent and overvoltage protection, and whether the protection board is fine workmanship, there will be a price difference. If all the batteries are taken away, the cheap battery increases the risk factor.
3, the input and output is added to the anti-static protection, increase the ability to protect static electricity.
4. Whether TVS protection is added at the power input, which can effectively prevent damage to the circuit caused by large current impact.
5. The performance of GSM antenna is very important. Is the transmission up to standard? Is the antenna up to standard? This antenna factory has to go through professional equipment debugging, antenna performance is good, four frequencies are up to standard, need to go through repeated testing and correction process. The bracket antenna needs to be opened on another bracket model. The overall price is high, solid, good performance, good consistency. Debugging a perfectly qualified GSM antenna sometimes takes a month or two. Cheaper products don't adjust too much, or they can adjust a band or two to take advantage of it. This substandard antenna has a high decay rate in service.
6, GPS tracker antenna debugging is relatively simple, if the conductivity is good, can be adjusted in a few days. The larger the antenna area, the better the satellite search effect, the faster the positioning speed.
Is each machine calibrated? Hardware is discrete, and the performance of each machine is different. The purpose of calibration is to pass professional instruments. Many cheap schemes do not calibrate and directly write all the mass production machines to a fixed value. Some only calibrate some parameters, such as PVT, ORFS, etc., without adjusting, saving a lot of labor costs, but producing machines with poor performance and high dropout rates.
8, testing is also divided into grades, semi-finished products, finished products, high and low temperature, aging, sampling. Have these steps been completed? What is the scope of the test software? These factors influence the test time.
9. Whether to support remote upgrade? Supporting remote upgrade is conducive to maintenance. Low maintenance costs when customers have special needs. You do not need to send back the device. The remote upgrade can solve the problem. It is efficient, especially for foreign customers. Transportation costs are higher than maintenance costs. Remote solution is best.
10. Current is a very important indicator because the wired machine is directly connected to the battery of the car, and if the current is high, it will lose power from the battery. In the running state, the average current is 20-30 mA. The running vehicle will charge the battery of the vehicle. At this time, the consumption of the battery can be ignored. The static current during sleep is a key indicator, because most cars sleep longer than they exercise. We can do less than 1 milliampere. Cheap machines sleep with a lot of current, which makes a big difference, and when they stop for a week or two without turning on, the battery will be consumed by this high current. Hire machines, influence. Improves the life of car battery. Keeping the current to a minimum is a test of kung fu. Hardware and software must have precipitation of research and development to achieve.