LapBook Pro charging problem

Hello, i have a problem with charging my laptop. Yesterday I have received my Lapbook Pro and I started to charge it and it stoped at 89%, even after addisional 4 hours charging it stayed the same. Today I tried again and from 75% to 82% it needed 1 hour and again stoped at 82%. Do you have any advice? Should I send it back?

Try to calibrate the battery, draining the battery until it turns off for two charging cycles (there are tutorials on youtube on how to do it) and check if afterwards the battery level reaches the maximum level