Tefal TY8751RH9A0 Replacement Battery 18V 3000mAh

Tefal TY8751RH9A0 / TY8758RH9A0 — 18V Ni-MH 3000mAh Replacement Battery

This is an 18V Ni-MH 3000mAh replacement battery for the Tefal TY8751RH9A0 and TY8758RH9A0 cordless handheld vacuum cleaners. It slots into the original battery housing and restores motor power to the suction head. Capacity matches the factory specification at 54Wh.

• TY8751RH9A0 and TY8758RH9A0 compatibility: Both models run the same 18V power rail, share the same battery connector format, and use the same BMS handshake. One cell fits both without modification.
• Bench tested on actual hardware: We ran this battery through full charge and discharge cycles on the TY8751RH9A0 motor platform. The BMS held steady under sustained suction load and tripped correctly when the filter restriction test pushed draw above threshold — then recovered cleanly once load dropped.
• Dock charging habit on these vacuums: Do not leave the vacuum sitting on the charging dock permanently. Tefal cordless vacuums on continuous dock charge develop capacity fade significantly faster than those charged only when depleted. Charge to full, then remove from the dock.

Suction dropping before the battery indicator reaches low

Ni-MH cells show a sharper voltage sag than lithium chemistry under heavy motor draw. On the TY8751RH9A0, the battery indicator reads remaining charge at rest voltage — not under load. When the motor spins up on thick carpet or against a partial blockage, the cell voltage dips fast, the motor loses torque, and suction drops noticeably while the indicator still shows partial charge. The fix is to clear any filter restriction first, then check that resting voltage after a full charge sits at or above 21.6V before use.

Motor cuts out mid-clean and then recovers after a pause

This is a BMS overcurrent trip, not a dead battery. When the filter is partially blocked, the motor draws more current than its rated load to maintain suction — the BMS reads this as an overcurrent event and shuts output to protect the cells. The vacuum recovers after a short pause because the BMS resets once current demand drops. Remove, clean, and dry the filter fully before the next run — a clean filter is the single fix that stops repeat trips on this platform.