KV8 210C Replacement Battery 14.4V Ni-MH 3500mAh

KV8 210C / 210XR — 14.4V Ni-MH Replacement Battery

This is a 14.4V Ni-MH battery pack rated at 3500mAh (50.4Wh), built to fit the KV8 210C and 210XR cordless vacuum cleaners. It replaces the original pack when capacity has dropped and the vacuum no longer holds a useful charge. No OEM part number is published for this model — fit is confirmed by voltage, connector, and physical dimensions.

• 210C and 210XR compatibility: Both models run the same 14.4V motor rail, use the same battery bay dimensions (90.06 × 69.53 × 45.45mm), and share the same connector orientation. One replacement cell covers both variants without modification.
• Bench tested on actual hardware: We cycled this pack through repeated discharge and charge sequences on a 14.4V Ni-MH test rig. The BMS maintained stable voltage delivery across the full discharge curve and responded correctly to charger termination signals with no false cutoffs.
• Dock charging habit on the 210C: Do not leave the 210C sitting on the charging dock continuously between uses. Ni-MH cells in cordless vacuums develop capacity fade noticeably faster under constant trickle charge than cells charged only when depleted. Charge to full, then remove the unit from the dock.

Suction dropping before the battery indicator reaches low on the 210C

This happens when the motor is pulling more current than rated — usually because a partially blocked filter is forcing the motor to work harder against restricted airflow. The battery voltage sags under that elevated draw even though the pack still has capacity remaining. The vacuum interprets this as normal operation, so the indicator stays mid-range while actual suction falls off. Clean or replace the filter first; if suction recovers, the battery is not the cause.

Motor cutting out mid-clean and recovering after a short pause

This is a BMS overcurrent trip, not a dead battery. When the motor sustains a high-draw condition — typically caused by a blocked brush roll or a clogged post-filter — current spikes past the BMS protection threshold and the pack shuts output. A short pause lets the BMS reset and the motor restarts, only to cut again if the restriction remains. Clear the brush roll and inspect both filters before assuming the battery is at fault. If the cutout persists on an unobstructed vacuum, verify pack voltage under load sits above 12.5V.