Apple AirPods Pro A1596 Replacement Battery 3.8V 390mAh

Apple AirPods Pro / AirPods 2 Charging Case — 3.8V Li-Polymer Replacement Battery (A1596)

This is a 3.8V, 390mAh lithium-polymer cell that replaces the original A1596 battery inside the AirPods Pro and AirPods 2 Charging Case. It fits case models MRXJ2ZP/A and MV7N2ZP/A, along with the standard AirPods Charging Case. Swap this in when the case stops holding charge or fails to top up the earbuds before the day is out.

• Case model compatibility: The MRXJ2ZP/A and MV7N2ZP/A cases share the same internal cell footprint, connector tab position, and BMS voltage thresholds — one cell covers both. The A1596 part number confirms the correct cell chemistry and charge curve expected by the case's charge controller.
• Bench tested on actual hardware: We ran the A1596 cell in a MRXJ2ZP/A case on the bench. The BMS accepted the cell without error, charge current stepped down correctly at 4.35V, and the case passed charge through to paired earbuds normally.
• First-charge protocol for case batteries: After fitting, place the case on a Lightning or MagSafe charger and run one full charge cycle before placing earbuds inside. The case controller recalibrates its state-of-charge estimate against the new cell during that first cycle — skipping this causes the LED to misread remaining capacity.

Why the AirPods case LED shows full but earbuds die faster than expected

The case stores its state-of-charge estimate in firmware, not in the cell itself. When a new cell goes in at storage voltage — typically 3.6–3.7V — the controller maps that voltage to a partial charge percentage rather than zero. The LED can show two or three bars while the usable capacity hasn't been fully characterised yet. One complete charge and discharge cycle resets the estimate. After that cycle, the LED reading and actual earbud top-up count will align.

Case not charging the earbuds after battery replacement

If the case charges via cable but the earbuds show no charge increase when seated, the cell voltage is likely still below the threshold the BMS requires before it enables the earbud charging rails. This typically happens when a new cell ships at storage voltage and the case hasn't completed its first full charge. Connect the case to a charger, wait until the LED holds steady white, then seat the earbuds. If the issue continues, check that the earbud contacts are clean — oxidation on the gold pads blocks current transfer regardless of case charge state.