What is the difference between the batteries of Ouda camera 1250mAh and 1300mAh?

The battery capacity differs by 50 mAh.

Although there is only a difference of 50mAH capacity, in actual use, you will feel that the battery power usage time is different. For example, 1300mAH can only be used for 2 hours, and changing to 1400mAH battery capacity can extend the service time. At the crucial moment, 50mAH can make the whole shooting work go on and end perfectly.

There is no difference except the battery capacity.

MAh: The unit of measurement of battery capacity is actually the total number of electrons in the battery that can be released for external use. The unit converted into the physical standard is the familiar coulomb. The international standard unit of coulomb is ampere-second of current multiplied by time:1mah = 0.001a× 3600s = 3.6as = 3.6 coulomb.