Nintendo Switch HAC-003 Compatible Battery 3.85V 4300mAh

Nintendo Switch HAC-001 / HAC-S-JP/EU-C0 — 3.85V Li-Polymer Replacement Battery (HAC-003)

This 3.85V, 4300mAh (16.55Wh) Li-Polymer cell replaces the original HAC-003 battery inside the Nintendo Switch console. It fits both the original HAC-001 and the HAC-S-JP/EU-C0 hardware revisions. Install it when the console no longer holds a charge through a handheld play session or fails to power on at all.

• HAC-001 and HAC-S-JP/EU-C0 compatibility: Both Switch hardware revisions use the same battery bay dimensions, connector pinout, and BMS communication protocol — so this single cell fits either board without modification.
• Bench tested on actual hardware: We seated this cell in a HAC-001 unit, confirmed BMS handshake on first boot, and watched the charge IC step through its constant-current and constant-voltage phases cleanly to termination with no fault flags.
• Fuel gauge calibration on first use: After installation, run one complete handheld session to automatic low-battery cutoff before recharging. The Switch fuel gauge IC sets its empty reference point against the first full discharge cycle — skipping this step produces inaccurate percentage readings from day one.

Why the Switch fuel gauge jumps or reads incorrectly after a cell swap

The Switch uses a gas-gauge IC that tracks charge by counting coulombs against a stored discharge curve learned from the original cell. A new cell has a different internal resistance profile, so the IC's stored curve no longer matches reality. Until the IC re-learns the new cell's behaviour across at least one full discharge cycle, it interpolates against stale data and the percentage display jumps — often from 40% to 5% with no warning. One complete discharge-to-cutoff followed by a full charge resets the reference and stabilises the readout.

Console shuts down before the battery indicator hits empty

This happens when the cell's resting voltage drops sharply under the combined load of the display, SoC, and wireless radio — faster than the fuel gauge can track. The BMS hits its low-voltage cutoff threshold before the percentage display reaches zero. It is common in the first three to five charge cycles on a new cell before the electrodes are fully conditioned. After conditioning cycles, internal resistance drops, voltage sag flattens, and the console reaches cutoff at a percentage much closer to 0%.