{"product_id":"jnc-ssf-f5100-replacement-battery-37v-450mah-li-ion","title":"JNC SSF-F5100 Compatible Battery 3.7V 450mAh Li-ion","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eJNC Sony Walkman SSF-F5100 — 3.7V Li-ion Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V Li-ion replacement battery for the Sony Walkman SSF-F5100 portable media player. Capacity is 450mAh (1.67Wh), matching the original cell specification. It fits directly into the SSF-F5100 and restores full device functionality when the original cell has degraded.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eSSF-F5100 platform fit:\u003c\/strong\u003e\n    The SSF-F5100 uses a single-cell 3.7V Li-ion pack with a simple two-wire or three-wire connector. No BMS handshake or proprietary authentication is required — the device reads voltage directly to determine charge state.\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 a media player test rig. The BMS protection circuit triggered correctly at the low-voltage cutoff threshold, and the cell accepted a full charge without thermal anomaly.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-use charge procedure for SSF-F5100:\u003c\/strong\u003e\n    After installing this cell, connect the charger before attempting to power on. If the player has been sitting discharged for weeks, it may enter deep discharge protection and require 20–30 minutes of trickle current before the device 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 after cell swap on the SSF-F5100\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eAfter replacing the cell, the SSF-F5100's charge indicator may read 80% one moment and drop to 20% the next. This happens because the player's fuel gauge is calibrated to the discharge curve of the old, degraded cell. The new cell has a flatter voltage curve across its actual capacity range, which the indicator misreads as erratic state-of-charge. Run two or three full charge-to-discharge cycles and the indicator will recalibrate to the new cell's 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\"\u003eAt the tail end of discharge, cell voltage drops below the threshold the audio amplifier needs to drive the output stage cleanly. The player cuts audio or shuts down even though the indicator still shows a partial charge. This is a voltage-sag issue, not a capacity issue — the cell still holds charge, but instantaneous voltage under amplifier load dips below the cutoff. If this happens early in the cell's life, check that the connector is fully seated; a loose contact adds resistance and accelerates voltage sag under load.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43381340012634,"sku":"BWCS-SFM5SL-1","price":23.99,"currency_code":"USD","in_stock":false},{"title":"Warranty 2 Year","offer_id":43381340045402,"sku":"BWCS-SFM5SL-2","price":26.99,"currency_code":"USD","in_stock":false},{"title":"Warranty 3 Year","offer_id":43381340078170,"sku":"BWCS-SFM5SL-3","price":29.99,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SFM5SL-big.webp?v=1778900029","url":"https:\/\/batteryweb.com\/products\/jnc-ssf-f5100-replacement-battery-37v-450mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}