{"product_id":"sony-ericsson-a2638-replacement-battery-37v-1400mah-li-ion","title":"BHC-11 Sony Ericsson A2638 Replacement Battery 3.7V 1400mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSony Ericsson A2638 Series — 3.7V Li-ion Replacement Battery (BHC-11)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V 1400mAh Li-ion replacement for the original BHC-11 battery. It fits the Sony Ericsson A2638, A2218, A2618s, and R300 — phones that share the same battery bay dimensions and connector pinout. Capacity matches the factory cell at 1400mAh (5.18Wh).\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eA2638 \/ A2218 \/ R300 platform fit:\u003c\/strong\u003e\n    These models use the same 3.7V rail, identical connector orientation, and a shared BMS handshake protocol. One battery revision covers the full range without modification.\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 the A2638 platform. The BMS accepted charge current without fault flags, and voltage held stable under modem-active load across the full discharge curve.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    After installing this cell, run one full uninterrupted discharge down to automatic shutdown, then charge to 100% without interruption. This gives the fuel gauge IC a clean reference curve for the new cell before the OS starts reporting percentage to the user.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the A2638 reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe A2638 uses a coulomb-counting fuel gauge IC that builds its charge model against the original cell's discharge curve. When a new cell goes in, the IC still references the old curve — so the percentage shown on screen doesn't match actual cell state. The mismatch can show up as a sudden jump from 40% to full, or a slow drain that reads 60% right until shutdown. One complete discharge-charge cycle resets the counter and trains the IC against the new cell's actual curve.\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 is a voltage cliff issue, not a capacity fault. Under peak load — active call, screen at full brightness, radio scanning — cell voltage can drop faster than the fuel gauge IC expects, hitting the BMS low-voltage cutoff while the display still shows 20–30%. The BMS trips at approximately 3.0V per cell to protect the chemistry. After shutdown, leave the phone off and place it on charge immediately; this lets the cell recover above the cutoff threshold before you power on again.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43409472520282,"sku":"BWCS-ERA2618XL-1","price":23.99,"currency_code":"USD","in_stock":false},{"title":"Warranty 2 Year","offer_id":43409472553050,"sku":"BWCS-ERA2618XL-2","price":26.99,"currency_code":"USD","in_stock":false},{"title":"Warranty 3 Year","offer_id":43409472585818,"sku":"BWCS-ERA2618XL-3","price":28.99,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-ERA2618XL-1.webp?v=1779579784","url":"https:\/\/batteryweb.com\/products\/sony-ericsson-a2638-replacement-battery-37v-1400mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}