Synergy Digital Speaker Battery, Works with Logitech S715i Speaker, (Ni-MH, 3.6V, 1500 mAh) Ultra High Capacity, Compatible with Logitech 180AAHC3TMX Battery - Walmart.com
Kastar 4-Pack Battery Replacement for Logitech S315i Rechargeable Speaker with iPhone/iPod Dock S-00078 984-000088 984-000084 984-000083 - Walmart.com