About this replacement
Amazon Kindle Fire 8 7th Generation — 3.7V Li-Polymer Replacement Battery (26S1014)
This 3.7V, 4650mAh lithium-polymer battery replaces the original cell in the Amazon Kindle Fire 8 7th Generation tablet, covering models SX034QT and SX0340T. It restores power to the display, processor, and wireless radio when the original cell no longer holds adequate charge. OEM part numbers 58-000181, MC-31A0B8, and 58-000219 also cross-reference to this replacement.
- Kindle Fire 8 7th Gen platform fit: The SX034QT and SX0340T share an identical connector pinout, cell footprint (119.86 × 98.85 × 2.70mm), and charge IC handshake — one cell covers all variants in this generation without modification.
- Bench tested on actual hardware: We cycled this cell through the Fire 8's charge controller and confirmed BMS communication, charge acceptance at the correct 4.2V cutoff, and stable output under simultaneous display and WiFi load.
- Fuel gauge reset after installation: After fitting this cell, run the tablet down to automatic shutoff, then charge uninterrupted to 100%. This resets the fuel gauge IC calibration against the new cell and clears the inaccurate percentage readings that commonly appear after a swap.
Kindle Fire 8 shutting down at 15–25% remaining
The Kindle Fire 8 runs a combined display and WiFi load that pulls enough current to cause a sharp voltage sag near the bottom of the discharge curve. The fuel gauge IC reads this sag as a critically low cell voltage and triggers an emergency cutoff — even though percentage still shows double digits. An aged original cell with higher internal resistance makes this worse. A new cell with lower internal resistance reduces the sag, but the fuel gauge still needs one full calibration cycle before it tracks the new cell's curve accurately.
Fast charging unavailable after battery swap on the Fire 8
Amazon's charge IC uses a negotiation cycle on the first accepted charge to confirm adapter and cell compatibility before enabling higher charge rates. After a battery replacement, this handshake resets. Plug the tablet into the original Amazon 5W or 9W adapter — not a third-party charger — and let it complete one full uninterrupted charge to 100%. After that cycle, the charge IC re-enables the faster charge profile and the amber-to-green indicator behaves normally again.