{"product_id":"itt-easymax-replacement-battery-37v-1050mah-li-ion","title":"ITT Easymax BL666 Replacement Battery 3.7V 1050mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eITT Easymax — 3.7V Li-ion Replacement Battery (BL666)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 1050mAh Li-ion cell for the ITT Easymax smartphone. It replaces part number BL666 when the original cell can no longer hold a charge or has failed completely. Voltage and physical dimensions match the original slot: 53.00 × 33.90 × 5.60mm.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eEasymax platform fit:\u003c\/strong\u003e\n    The Easymax uses a single-cell 3.7V nominal architecture with a dedicated charge IC on the main board. This cell matches that voltage rail and connector pinout, so the board's charge IC communicates with the replacement BMS without 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 Easymax platform and confirmed the BMS handshake completed correctly. The charge IC accepted the cell without throwing a fault, and the protection circuit tripped cleanly at the expected low-voltage cutoff.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle fuel gauge reset:\u003c\/strong\u003e\n    On first use after fitting, disable fast charging if your carrier or app allows it, then run one full discharge-to-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated state.\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 Easymax after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA new cell has a slightly different voltage-to-capacity curve than the aged cell the fuel gauge IC was calibrated against. When the modem fires up for a call or the screen hits full brightness, it pulls a current spike the cell can sustain — but the reported 20–30% figure is wrong. The real state of charge is already near the protection cutoff, so the BMS trips and the phone shuts down. One full discharge-to-charge cycle recalibrates the coulomb counter against the actual new cell curve. After that cycle, the percentage readings stabilise.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eUSB charging not recognised on the first connection after replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eWhen a new cell sits below roughly 3.0V from storage, the BMS may not present the expected handshake signal to the phone's charge IC on first plug-in. The phone sees a connected cable but registers no charging current. Connect the phone to a low-current USB source — a standard 5V 500mA port rather than a fast charger — for 10–15 minutes to bring the cell above the BMS re-engagement threshold of approximately 2.9–3.0V per cell. Once the BMS exits lockout, normal charging resumes and a fast charger will be recognised.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43405115981914,"sku":"BWCS-HFC250SL-1","price":21.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43405116014682,"sku":"BWCS-HFC250SL-2","price":24.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43405116047450,"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\/itt-easymax-replacement-battery-37v-1050mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}