{"product_id":"manta-4091s-replacement-battery-37v-1000mah-li-ion","title":"Manta 4091S Replacement Battery 3.7V 1000mAh Li-ion","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eManta 4091S \/ 4091S Dual SIM — 3.7V Li-ion Replacement Battery (TEL4091S)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 1000mAh Li-ion cell that replaces part number TEL4091S in the Manta 4091S and 4091S Dual SIM smartphones. It fits both single and dual-SIM variants, which share the same battery bay dimensions and connector pinout. Capacity matches the original spec at 3.7Wh.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003e4091S and 4091S Dual SIM compatibility:\u003c\/strong\u003e\n    Both handset variants run the same voltage rail and use an identical physical connector with the same BMS handshake protocol. The cell dimensions — 62 × 38 × 4.50mm — match the original battery bay exactly, so no modification is needed to fit either variant.\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 discharge on a Manta 4091S unit. The BMS accepted the new cell without fault codes, charge termination triggered correctly at 4.2V, and low-voltage cutoff held at the expected threshold without tripping prematurely under load.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    After fitting this cell, disable fast charging if your handset supports it and run one complete discharge-charge cycle before normal use. This gives the fuel gauge IC time to map the new cell's discharge curve — without it, the percentage readout can drift by 15–20% until calibration catches up.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the Manta 4091S reports the wrong battery percentage after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe fuel gauge IC on the 4091S uses a coulomb counter that was calibrated against the original cell's internal resistance and discharge curve. When a new cell goes in, that stored calibration no longer matches the actual cell chemistry. The gauge reads a voltage point and maps it to a percentage using old data, so it can appear 30% full when the cell is nearly flat — or vice versa. One full discharge down to automatic shutdown, followed by an uninterrupted charge to 100%, resets the coulomb counter against the new cell's real parameters.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–25% with the replacement cell installed\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the modem or display draws a surge of current and the cell voltage drops faster than the gauge expects — the phone hits the hardware undervoltage cutoff before the OS percentage reaches zero. It is a calibration issue, not a faulty cell. The BMS is cutting power at the correct voltage; the percentage shown is simply wrong because the fuel gauge has not yet mapped the new cell's voltage-to-capacity curve. Run the phone down to shutdown once, charge it fully without interruption, and the gauge will recalibrate — shutdown should then align with a reading below 5%.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43409489952858,"sku":"BWCS-NK4USL-1","price":21.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43409489985626,"sku":"BWCS-NK4USL-2","price":24.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43409490018394,"sku":"BWCS-NK4USL-3","price":26.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-NK4USL-1.webp?v=1779579814","url":"https:\/\/batteryweb.com\/products\/manta-4091s-replacement-battery-37v-1000mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}