{"product_id":"samsung-galaxy-a40-replacement-battery-385v-3000mah-li-polymer","title":"Samsung Galaxy A40 EB-BA405ABE Replacement Battery 3.85V 3000mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSamsung Galaxy A40 — 3.85V Li-Polymer Replacement Battery (EB-BA405ABE)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.85V, 3000mAh Li-Polymer battery for the Samsung Galaxy A40 smartphone. It fits the SM-A405FM\/DS, SM-A405FN\/DS, and related A40 2019 variants. It replaces OEM part numbers EB-BA405ABE and GH82-19582A directly.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eA40 series compatibility:\u003c\/strong\u003e\n    All SM-A405 variants share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The 3.85V nominal rail matches what the Exynos 7904 power management IC expects — swapping in a different voltage cell would trip the PMIC's overvoltage protection.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell on an SM-A405FN\/DS unit and confirmed the BMS completed charge termination correctly at 4.35V. The fuel gauge IC accepted the new cell and began coulomb counting without error flags on the first full cycle.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle fast charge tip:\u003c\/strong\u003e\n    After installation, disable fast charging in Settings and run one full discharge-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated cell — skipping this step causes erratic percentage readings in the first week.\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 Galaxy A40 after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThis is a voltage cliff, not a calibration error. A new cell with a slightly different discharge curve can hit a voltage floor that the PMIC reads as critical shutdown — even though the coulomb counter still shows capacity remaining. The Exynos 7904's PMIC cuts power when the cell drops below approximately 3.4V under modem or display load, and a fresh cell under peak current draw can sag to that point faster than the fuel gauge predicts. Run two complete discharge cycles without fast charging to let the coulomb counter recalibrate its end-of-discharge voltage model against the actual cell behavior.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eUSB-PD fast charge not activating on the first cycle after replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eOn the first charge cycle after a cell swap, the Galaxy A40's charge IC may not negotiate the 15W fast charge protocol because the BMS on the new cell has not yet confirmed a valid cell state to the PMIC. The charger falls back to standard 5V\/1A as a safety measure. This typically resolves after one complete charge cycle — plug in the original Samsung charger, allow a full charge to 100% at standard rate, then disconnect and reconnect to trigger fast charge renegotiation. If it still does not activate, check that the USB-C port is clean and the adapter output is 9V\/1.67A or higher.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43392010944602,"sku":"BWCS-SMA400SL-1","price":25.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43392010977370,"sku":"BWCS-SMA400SL-2","price":28.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43392011010138,"sku":"BWCS-SMA400SL-3","price":31.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SMA400SL-1.webp?v=1779142920","url":"https:\/\/batteryweb.com\/products\/samsung-galaxy-a40-replacement-battery-385v-3000mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}