Why can’t drones be used for more than half an hour?

This question should be ordinary civilian bai drones or du said consumer drones why zhi why not more than half an hour, because like military drones and dao some national research drones are not this limit.
The domestic drone market is mainly DJI, there are some small brands like millet ah. For drones power battery is usually lithium-core batteries, that is, what we call lithium batteries, LiPo said, each lithium battery voltage is usually 3.7v to 4.2v, that is, each lithium battery empty voltage of 3.7 full charge voltage of 4.2v. in the purchase of power batteries, we can see the battery on the label, power is what we use 3000mah, 4000mah, 5300mah or 10000mah and so on. It indicates how much electrical energy the power battery can store in mAh. And the discharge multiplier is usually there 15C, 20C, 25C or 30C and so on. It means the rate of discharge. For example, we have a 10000mah 20C battery.
1. discharging at 10,000 mAh for 1 hour; 2. discharging at 5 times the rate, i.e. 50,000 mAh for 12 minutes (60/5); 3. discharging at 10 times the rate, i.e. 100,000 mAh for 6 minutes (60/10); 4. discharging at 20 times the rate, i.e. 200,000 mAh for 3 minutes (60/20).

As for how much it will be discharged at what rate during the actual flight, it mainly depends on the ESC and the power of the motor, that is, the current consumption of the load. The factors affecting the capacity of the battery: 1.The discharge current of the battery: the higher the current, the lower the output capacity; 2.The discharge temperature of the battery: the lower the temperature, the lower the output capacity; 3.The cut-off voltage of the battery: it is set by the electrode material and the limit of the electrode reaction itself, the discharge is generally 3.5V or 3.2V.4.The number of charge and discharge times of the battery: after many times of charging and discharging, the battery will be discharged due to the electrode reaction. The failure of the material, the discharge capacity of the battery will be reduced accordingly.5.The charging conditions of the battery: the charging rate, temperature, cut-off voltage, etc. affect the capacity of the battery charged, thus determining the discharge capacity.

Product Name: 25000mAh 6S drone battery