Openlog wont log data if its conected to battery but when conected with usb (Micro;bit)

[heaofl]

first of all im not good when it comes to coding so im sorry for that in the first place, but i try to explain the problem as good as i can

I got a microbit and i have written the code. If i conect the micobit and power it over the usb port, the code works and the data logger logs the data that i want. When i plug in the batterie and dont insert a sd card, the blue light blinks and shows that he is in idle mode and that no sd card is inserted. that menas it should get enough power to work. but as soon as i put in the sd card, the blue light goes out and the green light flickers and no data is logged. I tryed different batteries, checked every cable but the only thing that is different is that im not using the usb to charge it but the batteries. WIth the usb its working but with the batteries not. Does anyboody know how to fix the problem ?