Not holding charge. Might need a new motherboard?

Anybody know where I can buy a new motherboard for my JBL Charge 5? I've been having issues with the battery not holding charge (which I've replaced and it still won't go past 60% plus drains quickly.) My guess is that this is my next logical step bar buying a new speaker altogether, guess it depends on how much a motherboard is. Thanks in advance for any and all help.