{"product_id":"yusun-la-i-replacement-battery-37v-1650mah-li-ion","title":"Yusun LA15 Replacement Battery 3.7V 1650mAh Li-ion","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eYusun LA-I \/ i2 \/ i2c — 3.7V Li-ion Replacement Battery (LA15)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V Li-ion cell rated at 1650mAh (6.11Wh), replacing the OEM LA15 battery in the Yusun LA-I, i2, and i2c smartphones. It fits the original battery bay without modification and connects to the same flex ribbon contact the phone's charge IC expects.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eLA-I, i2, and i2c compatibility:\u003c\/strong\u003e\n    All three models share the same 51.90 × 50.93 × 5.26mm battery footprint, identical 3.7V nominal voltage rail, and the same three-contact connector layout — so one cell covers the full platform without any wiring change.\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 LA-I platform and confirmed the BMS accepted the new cell without triggering a protection cutoff. The charge IC negotiated correctly and the cell held voltage within spec across the discharge curve.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    On first use after installation, disable fast charging and run one complete discharge-charge cycle. The fuel gauge IC is still calibrated to the old cell's discharge curve — this single cycle lets it re-anchor its coulomb counter to the new cell 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\"\u003eWhy the LA-I reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe phone's fuel gauge IC builds a discharge model based on the old cell's internal resistance and voltage curve. When a new cell goes in, the IC is still reading from its stored model, not the new cell's actual behaviour. This mismatch causes the percentage readout to jump ahead or fall behind real state of charge. One full discharge to 3.2V followed by a complete charge resets the coulomb counter and brings the gauge back into sync with the new cell.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on a freshly installed cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the modem, display, or both spike current demand and the cell voltage drops sharply under load — faster than the fuel gauge's rolling average catches. The phone's protection circuit reads the voltage dip as critically low and cuts power before the displayed percentage reaches zero. It is not a faulty cell. Run the first cycle without any active fast-charge protocol, which keeps charge current steady and lets the voltage floor settle predictably. After two full cycles the gauge average stabilises and the cutoff point tracks closer to the real 3.0V floor.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43404314050650,"sku":"BWCS-DVG250SL-1","price":28.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43404314083418,"sku":"BWCS-DVG250SL-2","price":32.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43404314116186,"sku":"BWCS-DVG250SL-3","price":34.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-DVG250SL-1.webp?v=1779369679","url":"https:\/\/batteryweb.com\/products\/yusun-la-i-replacement-battery-37v-1650mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}