earbuds

I throw away the swollen battery of my xiaomi earbuds2 but I wanted to use it without the case battery. It doesent charge without battery, so I connected the battery protection board to the board. It worked, but it makes a loud high pitched noise and kinda concerns me. Is it safe? And how do I...

I bought some rechargeable Earbuds. Very cheaply made. I cannot return them because I do not have the receipt. Besides, it's not worth the return. I plug them in to charge and the charge light on them go from Red for a split second and then stuck on Blue, but..turning them on does nothing. I...