{"product_id":"kddi-t618-replacement-battery-37v-900mah-li-ion","title":"KDDI T618 Replacement Battery 3.7V 900mAh Li-ion","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eKDDI T618 \/ T628 \/ T700 \/ T718 — 3.7V Li-ion Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 900mAh Li-ion replacement battery for the KDDI T618, T628, T700, and T718 mobile phones. It replaces a degraded original cell that no longer holds a full charge. Capacity figures come directly from the product specification — 900mAh \/ 3.33Wh.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eT618 \/ T628 \/ T700 \/ T718 platform fit:\u003c\/strong\u003e\n    These four KDDI handsets share the same physical cell footprint (53 × 34 × 4.80mm), voltage rail, and connector pinout. The battery slots into any of these models without modification to the housing or flex connector.\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. The BMS held the charge termination voltage at 4.2V and triggered protection cutoff cleanly at the low-voltage threshold — no false trips under steady load.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first install:\u003c\/strong\u003e\n    On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC build a fresh discharge curve against the new cell before high-current charging is applied to an uncalibrated state.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the T618 reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe fuel gauge IC in these KDDI handsets uses a stored discharge curve from the previous cell to calculate state of charge. When a new cell goes in, that curve no longer matches the actual cell chemistry — so the percentage shown on screen is wrong. The fix is one full uninterrupted discharge to auto-off followed by a full charge to 100% without interruption. After that cycle the coulomb counter resets its reference point and the percentage readout stabilises.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% charge remaining\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the cell voltage drops sharply under load — typically when the modem fires up for a call or data burst — and hits the BMS low-voltage cutoff even though the OS gauge still shows charge remaining. It is a fuel gauge calibration lag, not a faulty battery. Run one full discharge-charge cycle with all background sync and mobile data active so the gauge IC sees the actual voltage sag profile of the new cell. After calibration, the reported percentage and the real cutoff point align — target a resting voltage of around 3.7V at the 30% mark.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43405023805530,"sku":"BWCS-MY890SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43405023838298,"sku":"BWCS-MY890SL-2","price":27.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43405023871066,"sku":"BWCS-MY890SL-3","price":29.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-MY890SL-1.webp?v=1778767243","url":"https:\/\/batteryweb.com\/products\/kddi-t618-replacement-battery-37v-900mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}