{"product_id":"samsung-sch-u940-replacement-battery-37v-1000mah-li-ion","title":"Samsung SCH-U940 Replacement Battery AB603443EZ 3.7V 1000mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSamsung SCH-U940 \/ SCH-U940v — 3.7V Li-ion Replacement Battery (AB603443EZ)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 1000mAh Li-ion cell for the Samsung SCH-U940 and SCH-U940v flip phones. It slots directly into the original battery bay and uses the same OEM connector footprint. Voltage and capacity match the AB603443EZ specification exactly.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eSCH-U940 and U940v compatibility:\u003c\/strong\u003e\n    Both variants share the same battery bay dimensions, connector pinout, and 3.7V nominal voltage rail. The AB603443EZ part number covers both, so no hardware modification is needed to fit either model.\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 SCH-U940 platform. The BMS accepted charge current without flagging an error state, and the protection circuit tripped correctly at the low-voltage cutoff threshold.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    After fitting this cell, run one complete discharge down to automatic power-off, then charge uninterrupted to 100% before normal use. The phone's fuel gauge IC was calibrated to the old cell's discharge curve — this single full cycle resets the coulomb counter against the new cell's actual capacity.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the SCH-U940 reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe SCH-U940 tracks charge state using a fuel gauge IC that builds a discharge curve over many cycles. When you swap in a new cell, that stored curve no longer matches the actual cell chemistry. The IC reads voltage against the old curve and outputs an incorrect percentage. One full discharge-to-cutoff followed by a complete uninterrupted charge resets the reference table and brings the display percentage back in line with real capacity.\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 happens when the fuel gauge IC hasn't yet mapped the new cell's voltage cliff — the point where cell voltage drops sharply under load from the display or radio circuitry. The phone reads 20–30% on the old curve, but the actual cell voltage has already fallen below the BMS cutoff threshold under even moderate current draw. The fix is the same recalibration cycle: full discharge to auto power-off, then charge straight to 100%. After that cycle, the cutoff point should align correctly with what the display shows.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43405045006426,"sku":"BWCS-SMU940SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43405045039194,"sku":"BWCS-SMU940SL-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43405045071962,"sku":"BWCS-SMU940SL-3","price":28.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SMU940SL-1.webp?v=1779369859","url":"https:\/\/batteryweb.com\/products\/samsung-sch-u940-replacement-battery-37v-1000mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}