{"product_id":"sony-nw-e435-replacement-battery-37v-570mah-li-polymer","title":"Sony NW-E435 Replacement Battery 3.7V 570mAh 1-756-819-11","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSony NW-E435 \/ NWZ-E436 Series — 3.7V Li-Polymer Replacement Battery (1-756-819-11)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V 570mAh Li-Polymer battery for the Sony NW-E435, NW-E435F, SOK-NWZ-E435F(B), and NWZ-E436 Walkman digital audio players. It replaces OEM part number 1-756-819-11. The slim 3.56mm cell profile matches the original and fits the device's tight internal cavity without modification.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eNW-E435 and NWZ-E436 platform fit:\u003c\/strong\u003e\n    These models share the same 3.7V single-cell architecture, connector pinout, and BMS handshake protocol. One cell covers the full listed range without any wiring or adapter changes.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell through charge and discharge cycles on the NW-E435 platform. The BMS accepted the cell without error flags, and the charge controller stepped through the expected constant-current and constant-voltage phases cleanly.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-charge protocol after cell swap:\u003c\/strong\u003e\n    After installing a new cell, connect the player to a charger before attempting to power on. Media players in this series often enter a deep-discharge protection state during storage, which requires a slow trickle charge — sometimes 20 to 30 minutes — before the device accepts a normal charge current and responds to the power button.\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 erratically after cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe NW-E435 uses a voltage-threshold method to estimate charge level. After a cell replacement, the player's internal reference points no longer match the new cell's discharge curve. This causes the percentage display to jump — sometimes skipping from 80% to 20% without warning. Run two or three full charge-to-discharge cycles and the indicator recalibrates to the replacement cell's actual voltage curve.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003ePlayback cutting out before the battery indicator shows empty\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe audio amplifier in the NW-E435 draws a brief current spike when driving headphone output at higher volumes. Near the end of a discharge cycle, cell voltage sags under that load and briefly drops below the amplifier's minimum operating threshold. The player cuts audio output as a protective response, even if the battery indicator still reads a few percent remaining. If this happens consistently, the replacement cell is likely at or near end of discharge — connect the charger until the device reports full, then check that resting voltage reads 4.15V to 4.20V.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43381351481434,"sku":"BWCS-SAE430SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43381351514202,"sku":"BWCS-SAE430SL-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43381351546970,"sku":"BWCS-SAE430SL-3","price":29.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SAE430SL_1.webp?v=1778900081","url":"https:\/\/batteryweb.com\/products\/sony-nw-e435-replacement-battery-37v-570mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}