{"product_id":"sony-nwz-a720-replacement-battery-37v-650mah-li-polymer","title":"Sony NWZ-A720 Replacement Battery 3.7V 650mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSony NWZ-A720 \/ NWZ-A728 Series — 3.7V Li-Polymer Replacement Battery (1-756-702-11)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3.7V, 650mAh Li-Polymer battery replaces the original cell in the Sony NWZ-A720, NWZ-A728, NWZ-A726, and NWZ-820 Walkman media players. It matches OEM part numbers 1-756-702-11, LIS1374HNPA, and related variants. If your player refuses to hold a charge or dies mid-session, this is the direct replacement cell.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eNWZ-A720 \/ A726 \/ A728 \/ NWZ-820 platform fit:\u003c\/strong\u003e\n    These models share the same compact Li-Polymer cell format, connector pinout, and BMS voltage thresholds. One cell covers the whole series without any wiring or connector modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through charge and discharge on the NWZ-A728 platform. The BMS accepted full charge current without fault, and the protection circuit triggered correctly at the low-voltage cutoff point.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-swap charge protocol for Walkman players:\u003c\/strong\u003e\n    After fitting a new cell, connect the player to its charger before attempting to power it on. NWZ-series players can enter a deep-discharge protection state during storage or transit, and the firmware requires a short trickle-charge phase before it will accept normal charge current or boot.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBattery percentage jumping after cell swap on NWZ-A series players\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eAfter replacing the cell, the NWZ-A720 and related models may display erratic or incorrect battery percentage readings for the first several charge cycles. The firmware's fuel gauge is calibrated to the voltage curve of the original aged cell, not a fresh one. The indicator recalibrates by comparing actual resting voltage against its stored thresholds over repeated cycles. Run two or three full charge and discharge cycles to let the gauge settle.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003ePlayback cutting out before the battery indicator reaches empty\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eAs a Li-Polymer cell approaches the end of its discharge curve, terminal voltage drops sharply under the load of the audio amplifier circuit. The NWZ-A720's amplifier requires a stable voltage floor to sustain output — when the cell can no longer hold that floor, the player shuts down even if the gauge still shows remaining charge. This is amplifier voltage sag, not a faulty cell. If it happens consistently with a fresh replacement battery, check that the cell connector is fully seated, as a loose contact increases resistance and accelerates the voltage drop.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43381351383130,"sku":"BWCS-SA720SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43381351415898,"sku":"BWCS-SA720SL-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43381351448666,"sku":"BWCS-SA720SL-3","price":29.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SA720SL-1.webp?v=1778900081","url":"https:\/\/batteryweb.com\/products\/sony-nwz-a720-replacement-battery-37v-650mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}