BT - Synergy 3000, 3100, 3105, 3105 Twin, 3106, 3200, 3500, 3505, 4500, 5100, 5500, Mango, Fusion Homehub, Digital Clarity

NiCad 300mAh batteries are compatible with earlier 250 and 280mAh batteries NiMH 650 are compatible with 550, 600, 700mAh batteries NiMH 850mAh batteries are compatible with 750 and 800mAh batteries