{"product_id":"amplicomms-powertel-m4000-replacement-battery-37v-1050mah-li-ion","title":"Amplicomms Powertel M4000 Compatible Battery 3.7V 1050mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eAmplicomms Powertel M4000 \/ M5000 Series — 3.7V Li-ion Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3.7V, 1050mAh Li-ion cell replaces the original battery in the Amplicomms Powertel M4000, M5000, M5010, and M5100 — senior-focused mobile phones with amplified audio and accessibility features. Dimensions are 53.00 × 33.90 × 5.60mm. If the original cell no longer holds a usable charge, this is the direct swap.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eM4000 \/ M5000 series platform:\u003c\/strong\u003e\n    These models share the same battery bay geometry and voltage rail. One cell fits the full range without adapter or 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 M-series platform. The BMS accepted charge normally, protection circuits tripped correctly at low voltage, and no thermal anomalies were recorded during the charge phase.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    After installing a new cell, run the phone from 100% down to automatic shutdown without interruption, then charge uninterrupted to full. This gives the fuel gauge IC a complete reference curve for the new cell. Skip this step and the percentage readout will drift from the first day.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the Powertel M4000 reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe fuel gauge IC on the Powertel M-series uses a stored discharge curve calibrated to the original cell's impedance profile. A replacement cell — even at the same capacity — has a slightly different internal resistance. The IC maps percentage against voltage, so until it learns the new curve, it reports inaccurate figures. One full uninterrupted discharge-to-shutdown followed by a full charge resets the coulomb counter reference and brings the percentage display back into line.\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 — typically during a call, when the modem draws a sharp current spike. A new cell that hasn't completed a calibration cycle can show 25% on screen while the actual resting voltage is already near 3.5V. Under modem load, that drops fast enough to trip the low-voltage cutoff. Complete one full discharge cycle first. If shutdowns continue after that, check that resting voltage at \"20%\" reads above 3.6V with a multimeter at the battery terminals.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43405113720922,"sku":"BWCS-HFC250SL-1","price":21.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43405113753690,"sku":"BWCS-HFC250SL-2","price":24.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43405113786458,"sku":"BWCS-HFC250SL-3","price":26.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-HFC250SL-1.webp?v=1779369992","url":"https:\/\/batteryweb.com\/products\/amplicomms-powertel-m4000-replacement-battery-37v-1050mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}