{"product_id":"boostmobile-sph-m840-replacement-battery-37v-1900mah-li-ion","title":"EB494865VO Samsung SPH-M840 Compatible Battery 3.7V 1900mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eBoostMobile SPH-M840 \/ Galaxy Prevail II — 3.7V Li-ion Replacement Battery (EB494865VO)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V Li-ion cell rated at 1900mAh (7.03Wh), built to the EB494865VO specification. It fits the Samsung SPH-M840 (Boost Mobile variant), Galaxy Prevail II, and Galaxy Prevail 2. Install it when the original cell no longer holds a charge through a standard day of calls, texts, and data.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eSPH-M840 and Prevail II compatibility:\u003c\/strong\u003e\n    These models share the same battery bay dimensions, 3.7V nominal rail, and connector footprint. The EB494865VO spec covers all variants listed — no adapter or modification needed.\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-M840 platform. The BMS accepted the charge handshake on the first cycle, and voltage held within the expected window under both idle and active modem load.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    After installation, disable fast charging if available and run one full discharge down to automatic shutoff before recharging to 100%. This gives the fuel gauge IC a clean reference curve against the new cell before the OS starts reporting percentages.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on the SPH-M840\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens because the fuel gauge IC was calibrated to the old cell's discharge curve. When the new cell hits a voltage region the IC hasn't mapped yet, it misreads remaining capacity and the phone cuts out before the gauge reaches zero. The fix is a full discharge-recharge cycle with no interruptions. After one complete cycle, the coulomb counter resets its reference and percentage reporting stabilises.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003ePhone stays at 0% and won't power on after storage\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eIf a Li-ion cell drops below roughly 2.5V from extended storage, the BMS enters a lockout state to prevent unsafe charging. The SPH-M840 will show nothing on screen or a flat-battery icon and refuse to boot. Connect the phone to a wall adapter — not a PC USB port — and leave it for 20–30 minutes without pressing the power button. The charge IC delivers a low-current trickle that brings the cell back above the BMS re-enable threshold, typically around 3.0V, after which normal charging resumes.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43404319227994,"sku":"BWCS-SMM840XL-1","price":28.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43404319260762,"sku":"BWCS-SMM840XL-2","price":32.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43404319293530,"sku":"BWCS-SMM840XL-3","price":35.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SMM840XL-1.webp?v=1779369734","url":"https:\/\/batteryweb.com\/products\/boostmobile-sph-m840-replacement-battery-37v-1900mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}