Protect the terminals: tape, a cap, or one bag per battery.

Daiso Myeongdong Main Store (43 Myeongdong-gil) and Myeongdong Station Store (134-1 Toegye-ro) are both open 10 am-10 pm. The ₩2,000 gadget pouch (443 reviews) keeps batteries and cables apart. Insulating tape is 2 rolls for ₩1,000 with 1,444 reviews.