{"product_id":"samsung-sph-a420-replacement-battery-37v-800mah-li-ion","title":"AB463446BA Samsung SPH-A420 Replacement Battery 3.7V 800mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSamsung SPH-A420 \/ SPH-A580 Series — 3.7V Li-ion Replacement Battery (AB463446BA)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 800mAh Li-ion replacement battery for the Samsung SPH-A420, SPH-A580, SGH-D347, SGH-D407, and over 90 additional compatible models. It replaces OEM part numbers AB463446BA, AB463446BABSTD, AB553446BA, and AB553446BAB\/STD. Dimensions are 49.50 x 33.80 x 4.70mm — verify your original part number before installing.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eMulti-model fit across SPH and SGH lines:\u003c\/strong\u003e\n    The SPH-A420, SPH-A580, SGH-D347, and SGH-D407 share the same 3.7V cell format, connector pinout, and BMS handshake profile — which is why a single part number covers the full group.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through full charge and load discharge on compatible hardware. The BMS held charge termination correctly at 4.2V and engaged undervoltage protection at the expected low-cell threshold with no false cutoffs during mid-cycle load spikes.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    On first install, disable fast charging if available and run one full discharge-to-charge cycle before normal use. The phone's fuel gauge IC is calibrated to the old cell's discharge curve — one complete cycle lets it map the new cell's voltage profile and report accurate percentages.\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 SPH-A420 after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis is a fuel gauge IC mismatch, not a faulty battery. The phone's coulomb counter was calibrated against the discharge curve of the original, degraded cell — so its voltage-to-percentage mapping is wrong for a fresh cell. Under modem or screen load, the new cell's voltage briefly dips at a point the gauge misreads as empty, triggering an emergency shutdown. One full discharge cycle from 100% to automatic cutoff, then a full charge, forces the IC to relearn the new cell's curve and eliminates the false shutoff.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003ePhone feels warm near the battery during the first few charges\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA new Li-ion cell has higher internal impedance than a broken-in cell. During the first one to three charge cycles, the charge IC pushes current into that higher-impedance cell, which generates more heat than usual at the battery contact area. This is normal and resolves as the cell completes its initial formation cycles. If warmth persists beyond the third full charge or the phone becomes hot to the touch, stop charging and check that the replacement part number matches AB463446BA exactly.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43409451679834,"sku":"BWCS-SMU420SL-1","price":21.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43409451712602,"sku":"BWCS-SMU420SL-2","price":24.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43409451745370,"sku":"BWCS-SMU420SL-3","price":26.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SMU420SL-1.webp?v=1779579736","url":"https:\/\/batteryweb.com\/products\/samsung-sph-a420-replacement-battery-37v-800mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}