Roborock 1C Replacement Battery 14.4V 2500mAh Li-ion

Roborock 1C / STYTJ01ZHM — 14.4V Li-ion Replacement Battery (P1904-4S1P-MM)

This 14.4V, 2500mAh Li-ion battery replaces the original P1904-4S1P-MM pack in the Roborock 1C robotic vacuum (also sold as SKV4093GL, XM2000021, and STYTJ01ZHM). It fits directly into the battery bay with the original connector and BMS communication lines intact. Use it when the original cell can no longer hold a full charge or the robot shuts down mid-clean.

• 1C series compatibility: The 1C, SKV4093GL, XM2000021, and STYTJ01ZHM all share the same 14.4V 4S cell configuration and P1904-4S1P-MM connector housing. The BMS on this pack communicates the same charge and discharge status signals the robot's main board expects — no pairing step required.
• Bench tested on actual hardware: We ran this pack through full charge and discharge cycles on the 1C platform. The BMS held cell balance across all four series cells and triggered undervoltage cutoff cleanly at the expected threshold without nuisance trips during the motor-start surge.
• Dock charging habit on the 1C: The 1C has no active charge-termination logic that pulls itself off dock power once full. Leave it docked permanently and the cells trickle-charge continuously — this accelerates capacity fade faster than normal use cycles would. Charge to full, then remove from the dock.

Suction dropping before the battery indicator reaches low

The 1C motor draws significantly more current when the filter is partially blocked or the brush roll is tangled — often double the rated draw. That extra load pulls cell voltage down faster than the indicator's SOC algorithm expects, so the robot behaves as though the battery is depleted while the display still shows mid-charge. The BMS reads real cell voltage, not the displayed estimate, and will cut power to protect the cells. Clean the filter and check the brush roll before assuming the new battery is the cause.

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

This is a BMS overcurrent trip, not a dead battery. It happens when the motor sustains a restricted-airflow condition — usually a clogged filter or a partial brush-roll jam — long enough for current draw to exceed the BMS trip threshold. The pack resets itself once the overcurrent condition clears, which is why the robot restarts on its own. Clear the filter and inspect the brush roll; if the cutouts stop, the pack is functioning correctly. If cutouts persist on a clean machine, check that cell voltage at rest reads above 14.0V.