UniStrong UG-9LH Replacement Battery 3.7V 5700mAh

UniStrong UG903 7-inch Ruggedized Tablet — 3.7V Li-Polymer Replacement Battery (UG-9LH)

This is a 3.7V, 5700mAh Li-Polymer replacement battery for the UniStrong UG903 7-inch Ruggedized Tablet. It replaces OEM part number UG-9LH when the original cell degrades or no longer holds a charge. At 21.09Wh, it matches the factory energy rating for this platform.

• UG903 platform fit: The UG903 uses a single-cell Li-Polymer pack at 3.7V nominal. The BMS on this tablet communicates state-of-charge via a dedicated fuel gauge IC — the connector pinout and cell geometry must match exactly, and this replacement does.
• Bench tested on actual hardware: We cycled this battery through charge and discharge on the UG903 platform. The BMS accepted the cell without fault flags, and the charge IC held a stable taper current into the full-charge threshold.
• Post-swap fuel gauge reset: After fitting this battery, run the tablet down to automatic shutoff, then charge it uninterrupted to 100% without using it. The UG903 fuel gauge IC calibrates against actual cell voltage curves — skipping this step causes the percentage display to drift or jump.

UG903 shutting down at 15–25% battery remaining

The UG903 runs a high-contrast display alongside GPS and wireless radios simultaneously in the field. Under that combined load, the cell voltage drops sharply near the lower state-of-charge range — faster than the fuel gauge IC expects. The BMS reads this voltage sag as a critically low cell and triggers a protective shutdown before the percentage counter reaches zero. One full discharge-to-shutoff cycle followed by an uninterrupted charge recalibrates the fuel gauge and shifts the shutdown point back to the correct threshold.

Fast charging not available after battery swap on the UG903

The UG903 charge controller re-negotiates charging parameters after a new cell is fitted. On the first charge cycle post-swap, the device often defaults to standard charge current while the IC profiles the new cell's internal resistance. This is normal behaviour — not a fault with the replacement battery. Charge the tablet once to 100% at standard rate and fast-charge availability typically restores on the second cycle. If it does not, verify the charge cable supports the required current for the UG903's charge IC.