About this replacement
Trifo Emma Pet / Lucy — 14.4V Li-ion Replacement Battery (SUN-INTE-212)
This 14.4V, 5200mAh Li-ion battery replaces the original pack in the Trifo Emma Pet and Lucy robot vacuums. It fits both models directly, using OEM part numbers SUN-INTE-212 and SUN-INTE-278. Capacity figure is taken from the product data — 74.88Wh total energy.
- Emma Pet and Lucy compatibility: Both models run the same 14.4V power rail and use the same battery bay connector with matching BMS communication lines. One battery fits both — no adapter or modification needed.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge on a Trifo Emma Pet unit. The BMS handshook with the charger correctly, reported state-of-charge accurately to the vacuum's indicator, and held voltage above 13V through sustained high-suction load without tripping overcurrent cutoff.
- Dock charging behaviour on the Emma Pet and Lucy: Do not leave either vacuum sitting on the charging dock indefinitely between uses. These models apply a continuous trickle once full, which accelerates cell degradation faster than charge cycles alone. Charge to full, then remove from the dock until the next clean.
Suction dropping before the battery indicator shows low on the Emma Pet
This happens because the motor is drawing more current than rated, pulling pack voltage down early — not because the cell is empty. A partially clogged filter or brush roll tangle forces the motor to work harder, increasing current draw until the BMS sags voltage under load. The suction indicator reflects motor speed, not true battery percentage, so it drops before the battery LED signals anything. Clear the filter and check the brush roll first — if suction recovers immediately, the battery was not the cause.
Motor cuts out mid-clean and then recovers after a few seconds
This is a BMS overcurrent trip, not a dead battery. When suction is sustained against a blockage — packed pet hair in the brush channel, a saturated filter, or carpet fibres wrapped around the axle — current spikes past the BMS threshold and it cuts output to protect the cells. The pack recovers once current demand drops, which is why the vacuum restarts on its own. Clear the blockage, check the filter, then restart. If the trip repeats on a clean, unobstructed floor, verify pack voltage is above 14V before suspecting a fault.