About this replacement
Samsung Galaxy Tab S 8.4 — 3.8V Li-Polymer Replacement Battery (EB-BT705FBC)
This is a 3.8V, 4200mAh Li-Polymer replacement battery for the Samsung Galaxy Tab S 8.4. It fits SM-T700, SM-T705, and SM-T705C variants. Install it when the original cell no longer holds charge, drains unpredictably, or fails to power the tablet at all.
- SM-T700 and SM-T705 compatibility: Both Wi-Fi and LTE variants of the Tab S 8.4 use the same 3.8V cell with identical connector pitch and BMS handshake. The modem rail on the T705 draws from the same voltage bus, so one battery spec covers the full range.
- Bench tested on actual hardware: We cycled this cell on an SM-T705 under combined display and Wi-Fi load. The BMS held stable across charge and discharge without triggering low-voltage cutoff prematurely. Cell voltage at full charge measured within 0.05V of spec.
- Fuel gauge recalibration after install: After fitting this battery, run the tablet down to automatic shutoff, then charge uninterrupted to 100% before using it again. This resets the fuel gauge IC against the new cell and clears the inaccurate percentage readings that typically appear after a swap.
Tab S 8.4 shutting down between 15–25% remaining
The Exynos 5 chipset, AMOLED display, and Wi-Fi radio draw simultaneously during active use. When cell voltage dips under that combined load, the BMS reads it as a low-voltage fault and cuts power before the OS percentage reaches zero. This is a voltage-sag issue, not a capacity defect. A new cell with full charge capacity reduces the voltage drop under load and pushes the actual cutoff point much lower on the gauge.
Fast charging not available after battery swap
After a battery replacement, the charge IC sometimes defaults to standard charging until it completes one accepted charge cycle with the new cell. If the tablet is only showing slow charge speeds, plug into the original Samsung adaptive charger and let it run a full uninterrupted cycle to 100%. The charging protocol negotiation re-establishes after that cycle. If fast charge still does not activate, check that the charger output is at least 5V/2A — generic 1A adapters will not trigger the adaptive charging path.