{"product_id":"esia-music-box-replacement-battery-37v-1100mah-li-ion","title":"ESIA Music Box 3.7V 1100mAh Replacement Battery Li-ion","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eESIA Music Box — 3.7V Li-ion Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 1100mAh Li-ion cell for the ESIA Music Box portable audio device. It measures 54.70 × 34.33 × 7.10mm and matches the original cell's footprint and connector. Fit the replacement when the original cell no longer holds adequate charge through normal use.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eMusic Box power rail:\u003c\/strong\u003e\n    The Music Box runs its audio amplifier and Bluetooth stack off a single 3.7V Li-ion cell. This replacement targets that same voltage rail. No adapter or connector modification is needed — the cell slots into the same bay with the same orientation.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through a full charge-discharge sequence and monitored BMS cutoff at both the high-voltage ceiling (4.2V) and the low-voltage floor. The protection circuit tripped correctly at both limits with no thermal event.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first cycle:\u003c\/strong\u003e\n    On first use after installation, run one complete discharge down to auto-shutoff, then charge fully without interruption. This lets the fuel gauge IC build an accurate discharge curve against the new cell before reporting percentage readings to the device.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on a freshly installed cell\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThis is a voltage cliff issue, not a capacity fault. Under audio amplifier load, the new cell's terminal voltage drops faster than the fuel gauge IC expects — because the IC is still running a calibration curve from the old, degraded cell. The device interprets the voltage sag as a low-battery condition and shuts down before the displayed percentage reaches zero. One full discharge-to-shutoff cycle followed by a complete charge resets the coulomb counter and resolves the premature cutoff.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eDevice not powering on after the battery sat in storage\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-ion cells self-discharge during storage. If the cell drops below approximately 2.5V, the BMS enters lockout mode to prevent damage — and the device will show no signs of life when you press the power button. Connect the Music Box to a charger and leave it for 15–30 minutes without attempting to power it on. Most BMS circuits recover once a small trickle current pushes the cell voltage back above the 2.5V threshold, after which normal charging resumes.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43405094912090,"sku":"BWCS-HUC100SL-1","price":28.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43405094944858,"sku":"BWCS-HUC100SL-2","price":32.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43405094977626,"sku":"BWCS-HUC100SL-3","price":34.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-HUC100SL-1.webp?v=1779369956","url":"https:\/\/batteryweb.com\/products\/esia-music-box-replacement-battery-37v-1100mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}