About this replacement
Amazon Kindle Fire 7" 7th Generation — 3.7V Li-Polymer Replacement Battery (ST18 / 58-000177)
This 3.7V, 2950mAh Li-Polymer battery replaces the original cell in the Amazon Kindle Fire 7" and Kindle Fire 7th Generation 2017 (model SR043KL / B01GEW27DA). It matches the original form factor at 96.95 × 85.15 × 3.00mm and uses OEM part numbers ST18, ST18C, 58-000177, GB-S10-308594-060L, and MC-308594. Direct swap for a degraded or non-charging factory cell.
- Kindle Fire 7 and 7th Gen 2017 fitment: Both the standard Fire 7 and the 2017 refresh share the same 3.7V single-cell architecture, connector pinout, and BMS handshake — which is why one cell covers both generations. The fuel gauge IC communicates over the same line; no firmware difference affects compatibility.
- Bench tested on actual hardware: We cycled this cell on a Fire 7 7th Gen unit and confirmed the BMS accepted charge immediately, voltage held stable at 3.7V nominal under display-plus-WiFi load, and no protection cutoff triggered during normal operation.
- Fuel gauge reset after installation: After fitting the new cell, run the tablet down to automatic shutoff, then charge uninterrupted to 100% without using the device. This single full cycle recalibrates the fuel gauge IC against the new cell's actual capacity and clears the inaccurate percentage readings that typically appear after a swap.
Kindle Fire 7 shutting down at 15–25% remaining
This happens when the fuel gauge IC is calibrated to an aged cell with a steep voltage drop at the low end. The new cell has a flatter discharge curve, so the gauge misjudges the remaining capacity. When the display backlight and WiFi radio both draw current simultaneously, the combined load causes a voltage dip the BMS reads as a cutoff threshold. One full discharge-to-shutoff cycle followed by an uninterrupted charge to 100% resets the calibration and eliminates the early shutdown.
Fast charging not available after battery swap
The Kindle Fire 7 uses a proprietary charge negotiation sequence that runs one accepted charge cycle before the charge IC recognises the new cell's parameters. Plugging in after a cold swap often results in standard 5W input rather than the faster rate. Use the original Amazon power adapter — third-party adapters may not complete the negotiation handshake. After one full charge cycle with the Amazon adapter, fast charging resumes at the normal rate.