{"product_id":"anextex-sp230-replacement-battery-37v-1500mah-li-ion","title":"Samsung Galaxy S2 AnexTEX Replacement Battery 3.7V 1500mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eAnexTEX SP230 — 3.7V Li-ion Replacement Battery (BTR-4100)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V 1500mAh Li-ion replacement battery for the Samsung Galaxy S2 SP230. It slots into the same compartment as the original BTR-4100 cell and restores power to the device. Capacity is 1500mAh — use only what the product data confirms.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eSP230 platform fit:\u003c\/strong\u003e\n    The SP230 shares a fixed connector pinout and voltage rail with the original BTR-4100 cell. The BMS handshake relies on voltage tolerance staying within the Galaxy S2's charge IC window — this cell meets that spec without modification.\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 SP230 platform and logged BMS response at cutoff thresholds. The protection circuit triggered correctly at low-voltage floor, and the charge IC accepted the cell without error flags on the second cycle.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    After installing this cell, disable fast charging and run one full discharge-charge cycle before normal use. The Galaxy S2 fuel gauge IC calibrates its coulomb counter against the new cell's discharge curve on that first cycle — skipping it causes the OS to report inaccurate percentages for days.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the Galaxy S2 reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe SP230's fuel gauge IC builds its percentage model from the original cell's discharge curve stored in memory. When a new cell goes in, that stored curve no longer matches the actual cell chemistry, so the reported percentage drifts from reality. The IC needs a full uninterrupted discharge to near shutdown, followed by a complete charge to 4.2V, to rewrite its internal model. Until that cycle completes, expect percentage readings to jump or stall — this is the gauge recalibrating, not a fault with the cell.\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 cell voltage drops below the modem or display load threshold before the OS percentage catches up. The Galaxy S2's charge IC holds a minimum voltage floor around 3.4V per cell — if the cell cannot sustain that under peak load, the phone cuts out even though the gauge still shows charge remaining. A fresh cell showing this behaviour usually has an uncalibrated coulomb counter, not a defective cell. Run one complete discharge to shutdown and recharge to 4.2V — the cutoff events should stop after the gauge IC recalibrates to the new discharge curve.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43405151567962,"sku":"BWCS-SP230SL-1","price":27.99,"currency_code":"USD","in_stock":false},{"title":"Warranty 2 Year","offer_id":43405151600730,"sku":"BWCS-SP230SL-2","price":30.99,"currency_code":"USD","in_stock":false},{"title":"Warranty 3 Year","offer_id":43405151633498,"sku":"BWCS-SP230SL-3","price":33.99,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SP230SL-big.webp?v=1779370298","url":"https:\/\/batteryweb.com\/products\/anextex-sp230-replacement-battery-37v-1500mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}