ZTE V72 Tablet Li-Polymer Replacement Battery 3.7V 3400mAh

ZTE V72 / Velox — 3.7V Li-Polymer Replacement Battery (Li3734T42P5hC66045)

This is a 3.7V, 3400mAh Li-Polymer battery for the ZTE V72, V72a, and Velox tablets. It replaces OEM part Li3734T42P5hC66045. If your tablet no longer holds a charge or shuts down unexpectedly, this cell restores full power capacity to the board.

• V72, V72a, and Velox compatibility: All three models share the same 3.7V power rail, identical connector pinout, and the same BMS handshake protocol — which is why one cell covers the entire line without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a V72 unit. The BMS accepted the cell without fault flags, and the protection circuit triggered correctly at the low-voltage cutoff threshold.
• Fuel gauge recalibration after swap: After fitting this battery, run the tablet down to automatic shutoff — do not force power-off — then charge uninterrupted to 100%. This single full cycle lets the fuel gauge IC recalibrate against the new cell and eliminates the inaccurate percentage readings that almost always appear right after a replacement.

ZTE V72 shutting down at 15–25% remaining

This happens when the fuel gauge IC still holds calibration data from the old, degraded cell. When the display and Wi-Fi run together, the combined current draw causes a voltage dip the old calibration misreads as a low-battery cutoff. The tablet shuts down even though usable charge remains. One full discharge-to-shutoff and uninterrupted recharge to 100% resets the reference points the gauge uses — after that cycle, the shutoff point drops back to the correct level near 0%.

Fast charging stops working after battery replacement on the Velox

The Velox charge controller uses a proprietary negotiation step before enabling fast charge current. On a freshly installed cell, that negotiation sometimes fails on the first connection because the BMS has not yet completed an accepted charge cycle. Plug into the original ZTE charger — not a generic USB adapter — and let it complete one full charge without interruption. After that cycle, the controller recognises the cell and fast charge re-enables at the correct current level.