Motorola MZ604 Xoom SNN5881A Replacement Battery 7.4V 3250mAh

Motorola Xoom MZ604 Series — 7.4V Li-Polymer Replacement Battery (SNN5881A)

This 7.4V, 3250mAh Li-Polymer battery replaces the OEM SNN5881A cell in the Motorola Xoom tablet line. It fits the MZ604, MZ500, MZ600, and related Xoom variants that share the same battery bay and connector. Capacity figures come from the product data — 24.05Wh total.

• Xoom MZ500 / MZ600 / MZ604 platform fit: These Xoom variants share the same 7.4V battery rail, physical form factor, and BMS handshake protocol. One cell covers all of them — no connector modification needed.
• Bench tested on actual hardware: We ran this battery through charge and discharge cycles on a Xoom unit and confirmed the BMS communicates state-of-charge data correctly to the OS. Charge acceptance was normal across the full voltage range.
• Post-swap fuel gauge reset: After fitting this battery, run one full discharge to automatic shutoff, then charge uninterrupted to 100%. This forces the fuel gauge IC to recalibrate against the new cell's actual capacity curve and clears the erratic percentage readings that typically appear after a swap.

Xoom shutting down at 15–25% battery remaining

The Xoom's display backlight and WiFi radio together draw a sharp current spike that the original fuel gauge IC was calibrated to handle. When a new cell goes in, the IC still uses the old cell's voltage-to-capacity curve, so it misreads the actual remaining charge. The firmware triggers a protective shutdown when the reported voltage hits its cutoff threshold — even though real cell voltage is higher. One full discharge-to-shutoff cycle followed by an uninterrupted full charge resets that curve. After one cycle the shutdowns at 20% should stop.

Fast charging unavailable after Xoom battery replacement

The Xoom charge IC uses a negotiation handshake on the first accepted charge cycle to confirm cell chemistry and set the charge rate. With a new cell installed, this handshake has not yet completed, so the device defaults to a conservative slow-charge rate. This is not a fault with the battery or the charger. Plug into the original Motorola charger and allow one complete charge cycle from low to 100% — fast charge availability is restored after that first accepted cycle.