{"product_id":"kddi-is01-replacement-battery-37v-650mah-li-ion","title":"KDDI IS01 Replacement Battery 3.7V 650mAh SA001UAA","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eKDDI IS01 \/ SA001 Series — 3.7V Li-ion Replacement Battery (SA001UAA)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 650mAh Li-ion cell for the KDDI IS01, SA001, SA002, and K007 Android smartphones released in Japan. It replaces part numbers SA001UAA and KY003UAA. The cell matches the original dimensions at 53.70 × 34.80 × 3.80mm and slots into the same battery bay.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eIS01 \/ SA001 \/ SA002 \/ K007 platform fit:\u003c\/strong\u003e\n    These four models share the same battery bay dimensions, connector pinout, and BMS handshake protocol — one cell covers all four without any adapter or modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran a charge-discharge cycle on the IS01 and confirmed the BMS accepted the cell, reported voltage correctly, and held the charge IC in CC\/CV mode through a full cycle without tripping a protection cutoff.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    On the first charge after installation, disable any fast-charge mode if your charger supports it and run one complete discharge-charge cycle. This lets the fuel gauge IC map its coulomb counter to the new cell's actual discharge curve before high-current charging begins.\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 IS01 after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe IS01's fuel gauge IC retains the discharge curve from the old, degraded cell. When a new cell is installed, the IC does not immediately know where the real voltage cliff sits. Under screen or modem load, voltage can drop sharply at around 3.5–3.6V — below what the IC expected — and the BMS trips an undervoltage cutoff before the displayed percentage reaches zero. One full discharge-charge cycle resets the coulomb counter and moves the reported cutoff to match the new cell's actual curve.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eIS01 not powering on after the replacement battery sat in storage\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-ion cells self-discharge in storage. If the cell dropped below approximately 2.5V per cell, the BMS enters a hard lockout to prevent damage and will not respond to a normal charger. Connect the phone to a USB charger and leave it for 15–30 minutes without pressing the power button — the charge IC will trickle current into the cell at a low rate until voltage climbs above the BMS re-enable threshold, typically around 2.9V. Once the phone shows the charging indicator, proceed with a normal full charge cycle before first use.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43405116899418,"sku":"BWCS-KSA001SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43405116932186,"sku":"BWCS-KSA001SL-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43405116964954,"sku":"BWCS-KSA001SL-3","price":28.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-KSA001SL-1.webp?v=1779369992","url":"https:\/\/batteryweb.com\/products\/kddi-is01-replacement-battery-37v-650mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}