1, digital marking: the production dates of some batteries are marked with numbers. For example, "12 10 17" means that the production date is 201710 June12.

2. Coding: Some batteries need to be carefully identified when checking the production date. For example, the battery is printed with "4h3 1 1608 1". "4" stands for the output of 20 14 years, and "h" stands for August (1 month from a); "3 1" means random coding on the last day of 3 1.

3. Laser coding: Some production dates on the battery are laser coding, such as "20171123041a", which stands for 201765438+1October 23rd.