{"product_id":"myphone-q-smart-premium-replacement-battery-38v-2300mah-li-polymer","title":"MyPhone BM-09 Q-smart Premium Replacement Battery 3.8V 2300mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eMyPhone Q-smart Premium — 3.8V Li-Polymer Replacement Battery (BM-09)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.8V, 2300mAh Li-Polymer replacement battery for the MyPhone Q-smart Premium smartphone. It carries OEM part number BM-09 and fits directly into the Q-smart Premium's battery bay. It restores power to calls, messaging, apps, and display functions when the original cell has degraded or failed to hold a charge.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eQ-smart Premium compatibility:\u003c\/strong\u003e\n    The BM-09 cell matches the Q-smart Premium's 3.8V power rail and physical bay dimensions — 76.53 × 59.00 × 3.70mm. The BMS connector pinout aligns with the phone's charge IC, allowing normal charge and discharge handshaking without modifications.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through full discharge and charge sequences on the Q-smart Premium. The BMS held the charge cutoff at the correct upper voltage and the fuel gauge IC responded to cell data within two complete cycles.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle fuel gauge reset:\u003c\/strong\u003e\n    On first use after installation, disable fast charging and let the phone complete one full discharge-to-charge cycle. This lets the fuel gauge IC recalibrate its discharge curve against the new cell before high-current charging begins on an uncalibrated coulomb counter.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the Q-smart Premium reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe phone's fuel gauge IC stores a learned discharge curve from the original cell. When a new BM-09 cell goes in, the IC still references that old curve, so displayed percentage drifts from actual state of charge. This shows up as erratic jumps — the phone might read 45% and drop to 12% without significant use. One full discharge down to automatic shutdown, followed by a complete charge to 100%, forces the IC to rebuild its curve against the new cell's actual chemistry. After that cycle, percentage readings stabilise.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on the replacement BM-09 cell\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThis shutdown happens when the modem or screen draws a current spike that the new cell cannot sustain while the fuel gauge IC is still uncalibrated. The cell voltage sags below the BMS cutoff threshold — typically around 3.2V under load — and the phone shuts off even though the displayed percentage looks safe. It is not a faulty cell. Run the phone through two complete discharge-charge cycles without fast charging, and the IC will map the real voltage cliff of the new cell. Shutdowns at 20–30% should stop after calibration completes.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43392053248090,"sku":"BWCS-MYQ100SL-1","price":28.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43392053280858,"sku":"BWCS-MYQ100SL-2","price":32.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43392053313626,"sku":"BWCS-MYQ100SL-3","price":35.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-MYQ100SL-1.webp?v=1779143526","url":"https:\/\/batteryweb.com\/products\/myphone-q-smart-premium-replacement-battery-38v-2300mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}