{"product_id":"jbl-free-charging-case-replacement-battery-37v-1350mah-li-polymer","title":"JBL Free Charging Case Compatible Battery GSP803450 3.7V 1350mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eJBL Free Charging Case — 3.7V Li-Polymer Replacement Battery (GSP803450 01)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 1350mAh Li-Polymer replacement battery for the JBL Free Charging Case and JBL Free X TWS Charging Case. It fits directly inside the case housing and powers the internal cell that recharges the earbuds between wall top-ups. When the original cell degrades, the case stops holding enough charge to complete even one full earbud cycle — swapping this battery restores that function.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eFree and Free X TWS Case compatibility:\u003c\/strong\u003e\n    Both the JBL Free and Free X TWS charging cases use the same GSP803450 01 cell with the same connector and footprint. The BMS in both cases communicates with this cell the same way, so no firmware or hardware change is needed when swapping.\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 case PCB and confirmed the BMS accepted the pack, reported charge status correctly, and passed current to the earbud contacts without interruption.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eCase reconditioning after swap:\u003c\/strong\u003e\n    After fitting this battery, run the case from flat to full on wall power before placing the earbuds inside. This lets the case BMS calibrate its charge gauge against the new cell's actual capacity — skipping this step can cause the LED indicators to misread the charge level for the first several cycles.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the JBL Free Case LED shows full but the earbuds die after short use\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe case stores its charge estimate in firmware based on the original cell's behaviour. When the internal cell degrades heavily, the BMS can still show a full charge state while the actual deliverable capacity has dropped significantly. A new replacement cell won't fix the LED mismatch immediately — the case needs two or three full charge-discharge cycles before the firmware recalibrates to the new cell's real output. After those cycles, the LED indicators should track accurately again.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCase gets warm during charging but earbuds won't reach full charge\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis usually means the original cell has an elevated internal resistance, drawing more current as heat rather than storing it. The case PCB still drives charge current, but most of it dissipates before reaching the earbud contacts at useful voltage. Replacing the cell removes the high-resistance load. After fitting the new battery, confirm the case output voltage at the earbud contacts reads between 4.1V and 4.2V during active charging — anything below 3.9V points to a contact or connector issue rather than the cell itself.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43428114759770,"sku":"BWCS-JBX100SL-1","price":24.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43428114792538,"sku":"BWCS-JBX100SL-2","price":27.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43428114825306,"sku":"BWCS-JBX100SL-3","price":30.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-JBX100SL-1.webp?v=1779934164","url":"https:\/\/batteryweb.com\/products\/jbl-free-charging-case-replacement-battery-37v-1350mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}