{"product_id":"t-mobile-galaxy-s-ii-replacement-battery-37v-1800mah-li-ion","title":"Galaxy S II EB-L1D7IBA Compatible Battery 3.7V 1800mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eT-Mobile Galaxy S II SGH-T989 — 3.7V Li-ion Replacement Battery (EB-L1D7IBA)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 1800mAh Li-ion battery for the T-Mobile Galaxy S II (SGH-T989). It replaces OEM part EB-L1D7IBA and fits directly into the original battery bay. Cells degrade over charge cycles — this unit restores power to the processor, display, and wireless radios.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eSGH-T989 fit:\u003c\/strong\u003e The T989 uses a specific connector orientation and contact pitch that matches this cell's terminal layout. The BMS embedded in this pack communicates with the Galaxy S II's charge IC over the same three-pin interface as the original EB-L1D7IBA.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e We cycled this battery through charge and discharge on a T989 unit. The BMS held upper cutoff at 4.2V and triggered low-voltage cutoff cleanly without tripping the phone into a hard shutdown loop.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e After installing this cell, disable fast charging and run one full discharge to 5% followed by a complete charge to 100%. This gives the coulomb counter a known baseline against the new cell's 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 SGH-T989\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis is a voltage cliff issue. As Li-ion cells age, their internal resistance rises — under screen or modem load, voltage drops sharply even when the fuel gauge still shows charge remaining. The phone's hardware protection circuit reads real-time cell voltage, not the fuel gauge estimate, so it shuts down when voltage sags below the cutoff threshold. A fresh cell with lower internal resistance eliminates the sag. After fitting this replacement, run one full cycle so the coulomb counter re-maps the discharge curve — reported percentage will stabilise by the second cycle.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003ePhone reports wrong battery percentage after cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe Galaxy S II's fuel gauge IC stores a learned discharge model calibrated to the old cell's impedance and capacity curve. After a replacement, that model no longer matches the new cell — the chip interpolates incorrectly and shows skewed percentages. This causes jumps, stalls at certain levels, or early low-battery warnings. One full discharge from 100% down to automatic shutdown, then a full uninterrupted charge, forces the fuel gauge IC to rebuild its reference curve against the new cell. Percentages should read accurately within two cycles.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43405041565786,"sku":"BWCS-SMT989XL-1","price":28.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43405041598554,"sku":"BWCS-SMT989XL-2","price":32.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43405041631322,"sku":"BWCS-SMT989XL-3","price":34.99,"currency_code":"USD","in_stock":true}],"url":"https:\/\/batteryweb.com\/products\/t-mobile-galaxy-s-ii-replacement-battery-37v-1800mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}