Samsung plans to upgrade the battery of its upcoming foldable mobile phone. Interestingly, new evidence suggests that the company is testing two batteries for the Galaxy Z Flip 4. The good news is that the rated capacity of these two battery packs is higher than that of the Galaxy Z Flip 3 dual battery system.
 The Galaxy Z Flip 4 will be powered by two batteries, just like the previous Samsung folding phone. The file indicates that the 3300mAh unit inside the Galaxy Z Flip 3 has increased by 100mAh compared with the previous 3300mAh unit. However, according to the latest 3C certification file (via MyFixGuide), Samsung is also testing the battery pack with a rated capacity of 3595mAh.
 Galaxy Z Flip 4 will address one of the biggest weaknesses of Flip 3
 Samsung is testing two types of batteries, EB-BF723ABY and EB-BF724ABY. The rated capacity of the former is 2555mAh, and that of the latter is 1040mAh. Together, their capacity is 3595mAh.
 The models, especially the "F723" and "F724" components, indicate that these batteries will fall inside the Galaxy Z Flip 4.
 All this information should make it easier to guess the battery specifications of the Galaxy Z Flip 4, but this is not the case. 3C calls these two batteries "secondary batteries", which may also indicate that each of these batteries is applicable to different Z Flip models. After all, according to previous reports, Samsung may release three folding phones later this year.
 Or Samsung may have tested both batteries, but will decide which one to use as the auxiliary unit of the Galaxy Z Flip 4.
 In any case, Samsung plans to upgrade the batteries of the Z Flip series. Time will tell if it is 100mAh or more, but flip phone fans should welcome any improvements in this regard.