From PinkDragonTuning:
“A battery door that extends your battery tray space! Fits any large 2200mAH 3s up to 27mm thick.
Offered with styling greeblies or flat plain for moar sticker space
Possibly even fits some insano capacity 5000mAHs! I have not tested or bought a battery this large this myself but the dimensions check out!
Square compartment dimensions excluding non square nooks: 142mm x 54mm x 27mm”
You can purchase a physical print from the creator’s Etsy store here and/or download the files below.