About this replacement
Shark Cordless Stratos IZ840H / IZ862H — 25.2V Li-ion Replacement Battery (XBATR725SL)
This 25.2V 2000mAh Li-ion battery replaces part number XBATR725SL in Shark Cordless Stratos stick vacuums. It fits the IZ840H, IZ862H, and IZ862H T6 among other Stratos-series models. Voltage and capacity match OEM spec exactly.
- Stratos-series platform fit: The IZ840H and IZ862H share a 25.2V six-cell architecture with a common connector and BMS communication protocol. Any battery in this group must match that handshake or the vacuum will refuse to power on — this cell does.
- Bench tested on actual hardware: We ran this pack through full charge-discharge cycles on a Stratos unit, watching BMS cutoff thresholds under simulated motor load. The cell hit rated voltage at full charge and held above the BMS low-voltage cutoff under sustained suction draw.
- Dock charging habit on Stratos models: Do not leave the vacuum sitting on the charging dock between uses. Stratos chargers continue passing a trickle current once the pack is full. That constant low-level charge accelerates capacity fade faster than regular full-cycle use. Charge to full, then remove the vacuum from the dock.
Suction dropping before the battery indicator reaches low
This happens when the motor draws more current than the BMS allows under restricted airflow — not because the pack is depleted. A partially blocked filter forces the motor to work harder, spiking current draw above the BMS overcurrent threshold. The BMS responds by reducing output voltage to the motor, which reads as lost suction even with a full charge showing. Clean or replace the foam and felt filters first, then retest suction strength.
Motor cutting out mid-clean then recovering after a pause
This is a BMS overcurrent trip, not a dead battery. When sustained suction restriction pushes motor current past the pack's trip threshold, the BMS shuts output off to protect the cells. After a short pause the BMS resets, power returns, and the cycle repeats if the restriction is still present. Check the filter, the dust cup, and the brush roll for blockages before assuming the battery is at fault. A clean airflow path keeps current draw within the BMS's operating window.