Synergy Digital Speaker Battery, Works with Logitech UE MegaBoom 2 Speaker, (Li-ion, 3.7V, 3400mAh) Ultra High Capacity, Compatible with Logitech 533-000104, F12431581 Battery - Walmart.com
Battery for Speaker MEGABOOM S-00147 UE Ultimate Ears, 3400mAh
533-000116,533-000138 Battery for Logitech Ultimate Ears UE MegaBoom