{"product_id":"biackphone-bp1-replacement-battery-37v-2000mah-li-ion","title":"Biackphone BP1 Replacement Battery 3.7V 2000mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eBiackphone BP1 — 3.7V Li-ion Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 2000mAh (7.4Wh) Li-ion cell built to replace the original battery in the Biackphone BP1 smartphone. It matches the factory voltage and capacity spec, and fits within the BP1's 70.05 x 59.95 x 4.31mm battery bay. Use it when the original cell no longer holds a charge or fails to power the device through a full day.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eBP1 fitment:\u003c\/strong\u003e\n    The BP1 uses a single-cell 3.7V Li-ion pack with a dedicated fuel gauge IC that tracks charge via coulomb counting. This replacement cell matches the voltage rail and connector pinout that the BP1's charge controller expects.\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 calibrated rig, confirming the BMS accepts charge from the BP1's charge IC without cutoff or rejection on the first cycle at standard current.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\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 actual discharge curve before the OS starts reporting percentage from it.\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 the Biackphone BP1\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe BP1's modem and display draw current in short, high bursts. If the cell's internal resistance is elevated — either from age on the original or from an uncalibrated state on a new cell — terminal voltage drops sharply under that load. The fuel gauge IC reads voltage, not just stored charge, so a voltage dip below the cutoff threshold triggers an immediate shutdown even when the reported percentage looks safe. Running one full discharge cycle from 100% to auto-off and then charging to 100% uninterrupted recalibrates the coulomb counter and reduces false shutdowns.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBP1 reporting wrong battery percentage after cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe fuel gauge IC on the BP1 stores a learned discharge curve from the old cell in firmware registers. After a cell swap, that stored curve no longer matches the new cell's actual voltage-to-capacity profile. The OS pulls percentage from that stale curve, so the number on screen can read 40% and drop to zero without warning — or read 15% while the phone still has usable charge. One full uninterrupted charge to 100%, followed by a discharge to auto-off, forces the IC to rewrite the curve against the new cell. After that cycle, percentage reporting stabilises.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43404201754714,"sku":"BWCS-WKM001SL-1","price":24.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43404201787482,"sku":"BWCS-WKM001SL-2","price":27.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43404201820250,"sku":"BWCS-WKM001SL-3","price":30.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-WKM001SL-1.webp?v=1779369370","url":"https:\/\/batteryweb.com\/products\/biackphone-bp1-replacement-battery-37v-2000mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}