{"product_id":"virgin-mobile-montage-replacement-battery-37v-900mah-li-ion","title":"Virgin Mobile Montage 3.7V Compatible Battery 900mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eVirgin Mobile Montage \/ SPH-M350 — 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 Virgin Mobile Montage (SPH-M350) smartphone. It fits the battery bay directly and connects to the phone's charge and fuel gauge circuits. Capacity is 900mAh (3.33Wh), matching the original cell specification.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eMontage \/ SPH-M350 fitment:\u003c\/strong\u003e\n    Both model names refer to the same handset sold across different retail channels. The battery bay dimensions, connector pinout, and BMS communication protocol are identical across both variants — one cell fits both.\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 SPH-M350 platform. The BMS accepted the cell without error flags, and the charge IC negotiated current correctly from the first cycle.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    On first installation, run one complete discharge-charge cycle with fast charging disabled. The SPH-M350 fuel gauge IC holds calibration data from the old cell — one full cycle against the new discharge curve resets it and stops erratic percentage readings.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the Montage reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe SPH-M350 uses a coulomb counter in the fuel gauge IC that builds its model against the old cell's discharge curve. When you install a fresh cell, that model is stale. The phone reads voltage and maps it against the old curve, so the percentage shown can be off by 15–25% until the IC relearns. One full discharge to auto-shutoff followed by a complete charge cycle forces the IC to recalibrate against the new cell. After that cycle, percentage accuracy returns to normal.\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 phone's load — modem transmit bursts or screen brightness spikes — pulls more current than the cell voltage can sustain. The cell voltage drops below the BMS cutoff threshold even though the fuel gauge still shows charge remaining. It is a voltage cliff, not a capacity problem. The fix is to let the fuel gauge IC complete one full calibration cycle as above — once the IC has an accurate model of the new cell, it adjusts the low-voltage warning point and the early shutdowns stop.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43405118996570,"sku":"BWCS-SMT560SL-1","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43405119029338,"sku":"BWCS-SMT560SL-2","price":25.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43405119062106,"sku":"BWCS-SMT560SL-3","price":27.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SMT560SL-1.webp?v=1779370243","url":"https:\/\/batteryweb.com\/products\/virgin-mobile-montage-replacement-battery-37v-900mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}