{"product_id":"amoi-md-1-replacement-battery-37v-800mah-li-ion","title":"AMOI MD-1 Replacement Battery 3.7V 800mAh Li-ion","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eAMOI MD-1 — 3.7V Li-ion Replacement Battery (MD-1)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V 800mAh Li-ion battery for the AMOI MD-1 mobile phone. It replaces the original cell when the factory battery no longer holds a charge or fails to power the device. Capacity is 800mAh (2.96Wh), matching the original specification.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eMD-1 platform fit:\u003c\/strong\u003e\n    The MD-1 uses a single Li-ion cell at 3.7V nominal with a compact footprint measuring 51.76 × 37.98 × 4.34mm. This replacement matches that cell geometry and voltage rail so the device's charge IC sees the correct input parameters on startup.\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 a controlled rig. The BMS held the cutoff voltage correctly at both ends — no premature termination at the top and no undervoltage lockout triggered during normal draw at the bottom.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first cycle:\u003c\/strong\u003e\n    On first use after installation, run the phone down to automatic shutdown, then charge it uninterrupted to 100% before use. The MD-1's fuel gauge IC is calibrated to the old cell's discharge curve — one full cycle resets that reference against the new cell.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the MD-1 reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe MD-1 uses a fuel gauge IC that tracks charge state by comparing current draw against a stored discharge curve from the original cell. When a new cell goes in, that stored curve no longer matches actual cell behaviour, so the reported percentage drifts. This shows up most often as the phone displaying 40% and then shutting down without warning. One full discharge-to-shutdown followed by an uninterrupted charge to 100% forces the IC to re-map the curve against the new cell's actual capacity and internal resistance.\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 load threshold faster than the fuel gauge IC expects — a voltage cliff. Under screen-on or active-radio load, the cell cannot sustain voltage above the protection cutoff even though the reported percentage says it should have capacity remaining. The root cause is a mismatch between the IC's stored model and the new cell's actual voltage-versus-capacity curve. Complete the recalibration cycle first — discharge fully to auto-shutdown, then charge to 100% — and confirm the cell resting voltage reads 4.1–4.2V at full charge before normal use.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43405064896602,"sku":"BWCS-AMD001SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43405064929370,"sku":"BWCS-AMD001SL-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43405064962138,"sku":"BWCS-AMD001SL-3","price":28.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-AMD001SL_1.webp?v=1779369883","url":"https:\/\/batteryweb.com\/products\/amoi-md-1-replacement-battery-37v-800mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}