About this replacement
Microsoft Surface Go 1943 — 7.58V Li-Polymer Replacement Battery (DYNZ02)
This is a 7.58V, 5100mAh Li-Polymer battery for the Microsoft Surface Go (Model 1943). It fits the 10-inch 2-in-1 tablet and replaces OEM part DYNZ02 and 916TA135H. Swap it in when the original cell no longer holds a usable charge across a full day of use.
- Surface Go 1943 fitment: The 1943 model uses a flat Li-Polymer pack with a specific connector pitch and BMS handshake tied to Windows battery reporting. This battery matches that connector and communicates correctly with the Surface firmware so Windows recognises the pack and reports charge state accurately.
- Bench tested on actual hardware: We ran this pack through charge and discharge cycles on a Surface Go 1943 unit. The BMS accepted the charge handshake on the first cycle, and Windows battery reporting initialised without a hardware flag or driver warning.
- Fuel gauge calibration after installation: After fitting this battery, run one full discharge to automatic shutoff, then charge uninterrupted to 100% without using the tablet. This gives the fuel gauge IC a complete reference curve against the new cell and clears the inaccurate percentage readings that commonly appear after a swap.
Why the Surface Go 1943 shuts down at 15–25% remaining
The Surface Go draws simultaneous load from the display, WiFi, and background sync processes. Under that combined load, cell voltage drops sharply below the BMS cutoff threshold before the percentage gauge reaches zero. The fuel gauge IC was calibrated to the old, degraded cell, so the percentage shown no longer maps accurately to actual voltage. Running one full discharge-to-shutoff cycle after the swap recalibrates the curve and stops premature cutoffs.
Fast charging unavailable after battery replacement
If the Surface Go shows a slow or standard charge rate after a battery swap, the USB-PD negotiation between the charger and the new cell's BMS may not have completed a full accepted cycle yet. The charge controller confirms pack parameters before enabling higher current draw. Plug in the original Microsoft charger and let the tablet complete one uninterrupted charge from below 20% to 100%. After that cycle, USB-PD negotiation completes and the faster charge rate becomes available.