{"product_id":"hqrs-777-replacement-battery-37v-1200mah-li-ion","title":"HQRS 777 Smartphone Replacement Battery 3.7V 1200mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eHQRS 777 — 3.7V Li-ion Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 1200mAh (4.44Wh) Li-ion cell built to replace the original battery in the HQRS 777 smartphone. It targets devices where the stock cell has degraded, holds a short charge, or no longer powers on. Dimensions are 53.00 × 33.90 × 5.70mm — measure your original before installing.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eHQRS 777 fit:\u003c\/strong\u003e\n    The 777 uses a fixed 3.7V single-cell architecture with a direct connector to the charge IC. This cell matches that voltage rail and connector pinout, so the charge IC can communicate with the BMS without a logic mismatch.\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 3.7V single-cell platform, monitoring BMS cutoff at both ends. The protection circuit tripped correctly at low voltage and the charge IC accepted the cell without fault codes.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first cycle:\u003c\/strong\u003e\n    On first use after installation, disable fast charging and run one complete discharge-to-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging begins on an uncalibrated reference.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the HQRS 777 reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe fuel gauge IC on the 777 uses a coulomb counter calibrated to the original cell's discharge curve. When you install a new cell, that reference is stale. The IC doesn't know the new cell's actual capacity, so it reports percentages against the old curve. One full discharge-then-charge cycle forces the IC to relearn the endpoints and recalculate from a clean baseline.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on the replacement cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the cell voltage drops below what the modem or display load needs — typically under 3.5V — even though the gauge still reads 20–30%. It's a voltage cliff caused by the fuel gauge running on the wrong discharge curve after a cell swap. The fix is the same recalibration cycle: discharge the phone until it shuts off naturally, then charge uninterrupted to 100% with fast charging off. After one full cycle the gauge re-anchors and the shutdowns stop.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43404286066778,"sku":"BWCS-DEP215SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43404286099546,"sku":"BWCS-DEP215SL-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43404286132314,"sku":"BWCS-DEP215SL-3","price":28.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DEP215SL-1.webp?v=1779369550","url":"https:\/\/batteryweb.com\/products\/hqrs-777-replacement-battery-37v-1200mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}