{"product_id":"maxcom-m55-replacement-battery-37v-900mah-li-ion","title":"MaxCom M55 Replacement Battery 3.7V 900mAh Li-ion","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eMaxCom M55 \/ MM35D \/ MM36D \/ MM105 Series — 3.7V Li-ion Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V 900mAh Li-ion battery for the MaxCom M55 and compatible models including the MM35D, MM36D, and MM105. It covers a wide range of MaxCom handsets that share the same cell footprint and connector layout. Capacity is 3.33Wh as rated.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eM55, MM35D, MM36D, MM105 and extended range:\u003c\/strong\u003e\n    These models share a common 3.7V single-cell architecture with the same physical connector and BMS handshake protocol. Swapping between them uses the same cell format, so one replacement covers the full group without voltage rail or connector conflicts.\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 M55 platform. The onboard BMS accepted charge current without fault flags, and the fuel gauge IC tracked cell state across the full discharge curve as expected.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle fuel gauge reset:\u003c\/strong\u003e\n    After fitting this battery, disable fast charging if your device supports it and run one complete discharge-to-charge cycle. This lets the fuel gauge IC map its calibration points against the new cell's discharge curve before it starts reporting percentage to the OS accurately.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the M55 reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe MaxCom M55 uses a fuel gauge IC that builds its percentage model from the discharge curve of the original cell. When a new cell goes in, the IC is still referencing the old curve — so early readings will be off, sometimes by 15–25%. The gauge recalibrates itself over one or two full charge-discharge cycles by relearning the voltage-to-capacity relationship of the new cell. Until that calibration completes, percentage jumps and unexpected low-battery warnings are normal. Run the phone to near-empty and charge it fully twice to stabilise the readout.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on the replacement cell\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the fuel gauge IC is still calibrated to the old cell and the new cell hits a voltage cliff under load — typically when the modem fires or the screen brightness peaks — that the gauge didn't predict. The cell voltage drops below the BMS cutoff threshold faster than the percentage counter catches up. The fix is the same recalibration cycle: drain the battery until the phone shuts off on its own, then charge uninterrupted to 100% without removing it. After two full cycles the gauge aligns to the new cell's actual voltage floor, and shutdowns at false-high percentages stop.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43404206506074,"sku":"BWCS-KMC500SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43404206538842,"sku":"BWCS-KMC500SL-2","price":27.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43404206571610,"sku":"BWCS-KMC500SL-3","price":29.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-KMC500SL-1.webp?v=1779369391","url":"https:\/\/batteryweb.com\/products\/maxcom-m55-replacement-battery-37v-900mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}