{"product_id":"bea-fon-c70-replacement-battery-37v-900mah-li-ion","title":"Bea-fon C70 Replacement Battery 3.7V 900mAh Li-ion","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eBea-fon C70 \/ S400 Series — 3.7V Li-ion Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3.7V 900mAh (3.33Wh) Li-ion cell replaces the original battery in the Bea-fon C70, S400, S400 EU001B, S400 EU001W, and compatible variants. These are slim feature phones built around a compact battery bay — a flat cell measuring 53 x 34 x 4.30mm. Fit is exact; no trimming or adapter needed.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eC70 and S400 platform compatibility:\u003c\/strong\u003e\n    Both models share the same battery bay dimensions and voltage rail. The connector orientation and BMS handshake protocol are identical across the S400 EU001B and EU001W variants, so one cell covers the full lineup without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell through full charge and discharge cycles on the S400 platform. The BMS accepted the cell without fault codes, protection cut-off triggered correctly at low voltage, and charge termination fired at 4.2V as expected.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first install:\u003c\/strong\u003e\n    After fitting this cell, let the phone discharge fully to auto-shutdown, then charge to 100% uninterrupted. This gives the fuel gauge IC one complete reference cycle against the new cell's discharge curve before normal use.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the Bea-fon C70 reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eFeature phones like the C70 use a basic fuel gauge IC that builds its capacity model from the cell it first trained on. Swap the cell and the IC is now reading an unfamiliar discharge curve against an old map. The percentage displayed reflects where the old cell would have been at that voltage — not where the new cell actually sits. One full discharge-to-shutdown followed by a complete charge cycle resets the reference points the IC uses to calculate remaining capacity.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on the Bea-fon S400 after replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the fuel gauge IC hasn't calibrated to the new cell and the phone is still using the old discharge curve to estimate state-of-charge. Under load — an active call or backlight at full brightness — the cell voltage drops faster than the stale map predicts, and the BMS cuts power before the displayed percentage reaches zero. Run one full discharge cycle to auto-shutdown without interrupting charge. After that cycle, the IC recalculates the voltage cliff point and the shutdowns stop. Target a resting voltage of 3.6–3.7V at the 20% mark to confirm calibration is tracking correctly.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43405016236122,"sku":"BWCS-DEP510SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43405016268890,"sku":"BWCS-DEP510SL-2","price":27.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43405016301658,"sku":"BWCS-DEP510SL-3","price":29.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DEP510SL_1.webp?v=1779369805","url":"https:\/\/batteryweb.com\/products\/bea-fon-c70-replacement-battery-37v-900mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}