Battery won't change always 100%

I have installed 6 eufycam 2 pro cameras and used them for a week at the same place with same settings (recording 120 seconds when motion) to compare the batteries. 2 of 6 cameras showing 100% and 4 has dropped down to 89%. If i then try to charge those who has 100%, one is turning on the blue led for a second and then it turns off again. The second one seems to charge but it says 100% and the blue led staying on. Is those 2 defective? I have removed the cameras and added them again but it didn’t help.

The difference between 89% and 100% is minimal with new cameras. You don’t want them to be 100% all the time, it will damage your batteries and reduce capacity. Let them cycle until around 50-60%, then charge them.

No i don’t want them to be 100% all the time, I thought it was strange that 2 cameras was still at 100% after heavy use in a week and 4 dropped to 89% when they are mounted at the same place