Battery manufacturers tell you how to choose dry batteries?

Dry Battery is also called primary battery. I often use dry battery in my daily life, such as No. 5 and No. 7 Battery. Dry batteries all have the annoying disadvantage of self-discharge. The self-discharge is not only related to the internal factors of the battery, but also to the environmental temperature and humidity, it is necessary to make a selection. Common dry battery selection method: pay attention to check the production date, the shorter the storage period, the better; using a multimeter DC500mA block short-circuit current measurement, this method is simple but not accurate, and not safe, the essence is to judge its internal resistance from the instantaneous short-circuit current, the smaller the internal resistance, the better. If the method of twice measuring voltage is safe and reliable, two 2.2 V small electric balls are connected in parallel and then two clips are drawn out by a wire. The open circuit voltage of the battery is measured first, and then the small electric ball clips are clamped on the watch pen, then measure the voltage from the pool with load, compare the difference between the two voltages as small as possible. This method is more practical to distinguish 6 ~ 9V stacked batteries, at which point the small beads should be connected in series. All disposable batteries except rechargeable batteries are feasible. It is more accurate to use digital voltmeter instead.