Motorola Droid Razr XT912 EB20 Replacement Battery 3.7V 1700mAh

Motorola Droid Razr XT912 / XT910 — 3.7V Li-Polymer Replacement Battery (EB20 / SNN5899A)

This is a 3.7V, 1700mAh lithium-polymer replacement battery for the Motorola Droid Razr XT912 and XT910 smartphones. It replaces OEM part numbers EB20, SNN5899A, SNN5899, and SNN5899B. The cell fits the ultra-slim Razr chassis at 87.14 × 54.22 × 2.90mm and connects to the device's charge IC and fuel gauge IC through the standard three-contact flex connector.

• XT910 and XT912 platform compatibility: Both variants share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The EB20 cell works across the full Droid Razr lineup — hardware differences between XT910 and XT912 are radio band configurations, not power architecture.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the XT912 platform. The BMS accepted the cell without fault codes, charge current ramped correctly through CC/CV phases, and the fuel gauge IC tracked state-of-charge without erratic jumps after the first full cycle.
• Fuel gauge recalibration on first use: After fitting this cell, disable fast charging and run one full discharge-charge cycle before normal use. The fuel gauge IC retains the old cell's discharge curve in memory — one complete cycle lets it remap against the new cell and report accurate percentages going forward.

Sudden shutdown at 20–30% on the Droid Razr after a cell swap

The Droid Razr's processor, LTE modem, and AMOLED display can pull sharp current spikes simultaneously. A fresh lithium-polymer cell has slightly higher internal impedance than a broken-in cell, which causes voltage to sag under these combined loads. When pack voltage dips below the BMS's minimum threshold — typically around 3.2V under load — the phone shuts down even though the fuel gauge still reads 20–30%. After one or two full discharge-charge cycles, cell impedance drops and voltage sag under peak load normalises. If shutdowns persist past three cycles, check that the battery contacts are fully seated and clean.

Phone not powering on after the replacement battery sat in storage

Lithium-polymer cells discharge slowly during storage. If this battery shipped or sat unused long enough, the pack voltage may have dropped below 3.0V — the point where the BMS enters lockout mode to prevent cell damage. The phone will show no response on the power button because the BMS is blocking current output. Connect the phone to a wall charger, not a computer USB port, and leave it for 15–20 minutes without touching the power button. Most BMS circuits accept a slow trickle from the charge IC and will exit lockout once pack voltage climbs back above 3.2V.