About this replacement
Amazon Kindle HDX 7.0 — 3.7V Li-Polymer Replacement Battery (26S1001-A1)
This 3.7V, 4400mAh lithium-polymer battery fits the Amazon Kindle HDX 7.0 tablet and its related variants, including the P48WVB4, Kindle Fire HD 3rd generation, and KC5. It replaces OEM part numbers 26S1001-A1, 58-000055, 26S1005, and S12-T2-D. Capacity is 16.28Wh — matching the original cell specification for this 7-inch tablet platform.
- HDX 7.0 platform fit: The P48WVB4, KC5, and Fire HD 3rd generation share the same connector pinout, voltage rail, and BMS handshake protocol as the HDX 7.0. All pull from the same OEM part number family, which is why one cell covers the full group.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a Kindle HDX 7.0 unit. The BMS accepted the new cell without fault flags, held voltage through combined display and WiFi load, and hit 4400mAh within the second cycle.
- Post-swap fuel gauge reset: After installing this battery, run the tablet down to automatic shutoff, then charge uninterrupted to 100%. This forces the fuel gauge IC to recalibrate against the new cell. Without this step, the percentage display often reads incorrectly for several days.
Kindle HDX 7.0 shutting down at 15–25% battery remaining
This happens when the fuel gauge IC is still calibrated to the old, degraded cell. The original cell had a steep voltage cliff at low charge — the gauge mapped its cutoff point accordingly. A new cell with a flatter discharge curve hits that same voltage threshold later, but the IC triggers shutdown early because it's reading against the wrong profile. Running one full discharge to automatic shutoff followed by an uninterrupted charge to 100% resets the calibration. After that cycle, shutdowns below 20% stop.
Fast charging not available after battery swap on Kindle HDX 7.0
Amazon's charge controller requires at least one completed charge cycle before it unlocks higher charge rates on a new cell. This is a BMS-level protection — the IC runs the first cycle at a reduced current to profile the new cell's internal resistance. Plug in using the original Amazon 9W charger, let it run a full charge uninterrupted, and disconnect only after the indicator shows 100%. Fast charge typically becomes available from the second cycle onward.