About this replacement
HP Slate 8 Pro / Slate 8 Plus — 3.7V Li-Polymer Replacement Battery (HSTNH-C13C-S)
This 3.7V, 5650mAh (20.91Wh) lithium-polymer battery replaces part number HSTNH-C13C-S in the HP Slate 8 Pro and Slate 8 Plus tablets, including model variants 7600US and HSTNH-H408C. It fits the original battery bay without modification and connects via the stock internal connector. Capacity matches the factory specification listed in product data.
- Slate 8 Pro and Slate 8 Plus compatibility: Both models share the same 3.7V battery rail, physical footprint, and BMS handshake protocol — the HSTNH-C13C-S part number covers both. The BY02 and BY02021 references are alternate OEM codes for the same cell, not different batteries.
- Bench tested on actual hardware: We ran this cell through a full charge cycle on a Slate 8 Pro unit. The charge IC accepted the cell without fault flags, BMS communication stayed active throughout, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
- Fuel gauge recalibration after installation: Once installed, run the tablet down to automatic shutoff, then charge it uninterrupted to 100% before using it again. The fuel gauge IC was calibrated to the old cell — one complete cycle resets it against the new one and clears inaccurate percentage readings from the start.
Why the Slate 8 Pro shuts down at 15–25% remaining
The Slate 8 Pro drives a backlit display and active WiFi simultaneously — both are voltage-sensitive loads. When the cell voltage dips under combined draw, the BMS interprets it as a low-voltage condition and cuts power before the reported percentage reaches zero. This is a calibration issue, not a cell fault. After one full discharge-to-shutoff cycle followed by an uninterrupted charge to 100%, the fuel gauge IC remaps the actual voltage curve of the new cell and the early shutdowns stop.
Fast charging unavailable after battery swap on the Slate 8 Plus
Some users find the tablet reverts to standard charge speeds after a battery replacement. The charge controller re-negotiates its charging profile on the first accepted cycle with a new cell — this is expected behaviour, not a faulty battery. Let the tablet complete one full charge from near-zero to 100% via the original HP charger without interruption. After that cycle, the controller locks in the correct charge profile and faster input rates resume. Confirm with the original HP charger, not a third-party cable, as input voltage floor matters here.