Common batteries for headlights

1. Alkaline batteries are the most commonly used batteries. Its electric energy is higher than that of lead batteries, and it cannot be charged. At low temperature 0F, the power is only 10%~20%. The Voltage will be significantly reduced when it is used.

2. Nickel cadmium batteries: It can be recharged for thousands of times, and can maintain a certain use power. It can not compare with the electric energy stored by alkaline batteries. The power at 0F is still 70% at low temperature. It is better to carry high-energy batteries during rock climbing, which are 2-3 times higher than standard batteries.

3. Lithium battery: its electric energy voltage is 2 times higher than that of ordinary batteries. Two alkaline batteries whose ampere value/hour is more than 2 times of that of a lithium battery are used at 0F as if they were at room temperature, but they are very expensive. Their voltage can be kept constant. It is especially useful at high altitudes.