Lilin Robot LL-A320 Replacement Battery 14.4V 3500mAh

Lilin Robot LL-A320 Series — 14.4V Ni-MH Replacement Battery

This is a 14.4V, 3500mAh Ni-MH replacement battery for the Lilin Robot robotic vacuum cleaner range. It fits the LL-A320, LL-A325, LL-A335, and LL-A336 among others. Capacity is sourced from the product specification — 3500mAh (50.4Wh).

• LL-A320 series compatibility: The LL-A320, LL-A325, LL-A335, and LL-A336 share the same 14.4V battery platform and connector format. The motor drive circuit and BMS voltage thresholds are consistent across this model family, which is why one cell pack covers all of them.
• Bench tested on actual hardware: We cycled this cell through full discharge and recharge sequences on compatible hardware. The BMS held cutoff voltage correctly at low-end draw and did not trip during the motor start surge typical of robotic vacuum units on hard-floor-to-carpet transitions.
• Dock charging behaviour on Lilin Robot vacuums: Do not leave this vacuum sitting on the charging dock between uses. Lilin Robot's dock delivers a trickle charge that does not stop when the cell is full. Remove the unit from the dock once charging is complete to slow capacity fade.

Suction dropping before the battery indicator reaches low on the LL-A320

This happens when cell capacity has faded enough that voltage sags under motor load before the indicator circuit registers a low-battery state. The indicator measures resting or lightly loaded voltage — not the voltage under the full draw of the suction motor. A partially blocked filter makes this worse because the motor compensates by drawing harder, accelerating the voltage sag. Replacing the battery cell restores the voltage headroom the motor needs to maintain consistent suction through a full cleaning run.

Motor cuts out mid-clean and then recovers after a few seconds

This is a BMS overcurrent trip, not a motor fault. When the filter is restricted or the vacuum picks up a blockage, the motor pulls current above the BMS's safe threshold and the pack shuts output to protect the cells. After a few seconds the BMS resets and power returns. Clean or replace the filter first — if the cutouts stop, the battery was fine. If cutouts continue with a clean filter and a new battery, check the brush roll for hair or debris jamming the motor and forcing sustained high-current draw. Confirm the BMS trip threshold by checking that pack voltage returns to above 13.0V within 10 seconds of cutout.