A mobile phone manufacturer launched a new mobile phone, compared with the old model, except for the greatly improved battery life, the other styles and configurations of the new mobile phone have not changed  In the three months after the old phone was sold at the same time as the new phone, the sales of the old phone outsold the new phone
More and more consumers tend to buy portable battery to extend the battery life of their mobile phones
 As a result, the mobile phone manufacturer has come to the conclusion that battery life is not the primary consideration for customers