Amazon.com: Synergy Digital Dog Collar Battery, Works with Garmin TT15 Dog Collar, (Li-Ion, 3.7V, 2200 mAh), Compatible with Garmin 010-10806-30, Garmin - 010-11828-03, Garmin - 361-00029-02 Battery : Electronics
Alpha 100 with TT 15/TT 15 mini - Installing the New Battery
Garmin Mini Battery | Replacement for Mini TT15 or T5 | Okie Dog Supply