{"product_id":"telstra-f480-replacement-battery-37v-850mah-li-ion","title":"Telstra F480 Replacement Battery 3.7V 850mAh Li-ion","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eTelstra F480 \/ F480T — 3.7V Li-ion Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V 850mAh Li-ion replacement battery for the Telstra F480 and F480T mobile phones. It slots into the original battery bay and restores power to these early-2000s handsets. Capacity is 850mAh — matching the original cell specification.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eF480 and F480T compatibility:\u003c\/strong\u003e\n    Both models share the same battery bay dimensions, voltage rail, and connector pinout. One cell covers both variants — no hardware modification needed.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran a full discharge-charge cycle on the F480 platform. The BMS accepted the cell on first insertion, and the charge IC engaged normally without throwing a fault state.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first cycle:\u003c\/strong\u003e\n    After installing this cell, run one complete discharge down to automatic shutoff, then charge to 100% without interruption. The F480's fuel gauge IC is calibrated to the old cell's discharge curve — skipping this step causes erratic percentage readings from the first day of use.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the F480 reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe F480 uses a fuel gauge IC that tracks charge state against a stored discharge curve from the previous cell. A new cell has a different internal impedance profile, so the IC's stored curve no longer matches real voltage behaviour. The result is percentage readings that jump around or stall at values like 40% before the phone cuts off. One full discharge-charge cycle rewrites the reference curve and brings the percentage display back in line with actual charge state.\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 BMS cutoff threshold under load — even though the fuel gauge still shows charge remaining. On the F480, the display backlight and call radio pulling current simultaneously can cause a brief voltage sag that triggers the protection circuit. It is most common in the first few cycles before the fuel gauge IC recalibrates. Run one full cycle and check that resting voltage reads above 3.6V before the next use.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43409448599642,"sku":"BWCS-SMF480SL-1","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43409448632410,"sku":"BWCS-SMF480SL-2","price":25.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43409448665178,"sku":"BWCS-SMF480SL-3","price":27.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SMF480SL-1.webp?v=1779579708","url":"https:\/\/batteryweb.com\/products\/telstra-f480-replacement-battery-37v-850mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}