The PT-90 requires four AAA batteries to operate. The manual specifies that they must be fresh, alkaline (non-rechargeable) batteries. This unit is VERY sensitive to batteries that are even a tiny bit weak, even one of the four. If you try to print a label and the charge isn’t up to it, the unit shuts off.
https://www.amazon.com/Brother-P-touch-Personal-Labeler-PT-90/dp/B002M7W9GW

