Electrolux 7.2V Cordless Vacuum Compatible Battery OSBP72LI25

Electrolux 900257877 / ERV7210TG Series — 7.2V Li-ion Replacement Battery (OSBP72LI25)

This is a 7.2V 3400mAh Li-ion battery for Electrolux cordless stick and handheld vacuum cleaners. It fits model 900257877, ERV7210TG, ERV7200DB, 900257983, and 28 additional Electrolux cordless vacuum models using OEM part OSBP72LI25. Voltage and capacity match the original cell exactly.

• ERV7210TG and 900257877 platform: These models share a common 7.2V battery bay and BMS handshake protocol. The connector pinout and cell voltage threshold are identical across this range, so one replacement covers the full group without modification.
• Bench tested on actual hardware: We cycled this battery under vacuum motor load on a 900257877 unit. The BMS held the discharge cutoff correctly and the cell delivered consistent voltage across the full draw curve without premature shutdown.
• Dock charging behaviour on Electrolux stick vacs: Do not leave the vacuum sitting on the charging dock between uses. These models trickle-charge when docked continuously, and that sustained low-current charge degrades cell capacity faster than normal cycle use. Charge to full, then remove from the dock.

Suction dropping before the battery indicator shows low

The indicator LED on these Electrolux models reads state-of-charge from voltage alone, not from actual motor draw. When the filter is partially blocked, the motor pulls more current than rated, which collapses cell voltage under load faster than the indicator tracks. The vacuum loses suction while the light still shows adequate charge. Clean the filter first — if suction recovers immediately, the battery is not the fault. If suction remains weak after a clean filter, cell capacity has dropped below the threshold needed to sustain motor voltage above 6.5V under load.

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

This is a BMS overcurrent trip, not a flat battery. When suction is restricted — blocked filter, clogged nozzle, or hair wrapped around the brush roll — the motor stalls briefly and draws a current spike. The BMS reads that spike as an unsafe overload and cuts power to protect the cell. It resets after a few seconds once the current drops. Clear the blockage completely before the next run. If the cut-out continues on a clear filter with a new battery, check the brush roll bearing for drag, as a worn bearing produces the same sustained current spike that triggers the trip.