Amazon.com: MPF Products 2000mAh High Capacity 180AAHC3TMX, 993-000459 Battery Replacement Compatible with Logitech S315i, S715i, Z515 Portable Speaker : Electronics
2000mAh High Capacity 180AAHC3TMX, 993-000459 Battery Replacement for Logitech S315i, S715i, Z515 Portable Speakers - Newegg.com
Modding a logitech S715i with an external lithium battery - YouTube
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