{"product_id":"blu-hero-2-replacement-battery-37v-1200mah-li-ion","title":"BLU Hero 2 Replacement Battery N4D110J 3.7V 1200mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eBLU Hero 2 — 3.7V Li-ion Replacement Battery (N4D110J)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 1200mAh Li-ion battery for the BLU Hero 2 smartphone. It replaces the original N4D110J cell when the existing battery degrades, swells, or stops holding a charge. Capacity figures come from the product data: 1200mAh \/ 4.44Wh.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eHero 2 platform fit:\u003c\/strong\u003e\n    The Hero 2 uses a fixed 3.7V single-cell architecture with a compact 60.00 × 43.80 × 4.50mm footprint. This replacement matches that form factor and voltage rail exactly, so the charge IC and connector align 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 Hero 2 platform. The BMS accepted the new cell without error flags, and the charge IC completed a full cycle to 4.2V cutoff with no thermal interruption.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    Disable fast charging for the first complete discharge-charge cycle after installation. The fuel gauge IC on the Hero 2 is calibrated to the old cell's discharge curve — one full cycle at standard rate lets it relearn the new cell before high-current charging begins.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the Hero 2 reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe Hero 2 uses a coulomb-counter-based fuel gauge IC that stores a learned discharge curve from the original cell. When a new cell goes in, that stored curve no longer matches the actual voltage-to-capacity relationship of the replacement. The OS reads a percentage derived from the old curve, so it shows inflated or deflated numbers. One full discharge-charge cycle at standard current rate forces the IC to rewrite the reference curve against the new cell's actual behaviour.\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 is a voltage cliff issue, not a capacity defect. Under modem or screen load, the cell voltage drops sharply around 3.5–3.6V before the fuel gauge expects it, and the protection circuit cuts power to prevent under-voltage damage. On a fresh cell that hasn't been calibrated, the gauge doesn't anticipate that drop. Run one complete discharge to automatic cutoff, then charge uninterrupted to 100% — after that cycle, the fuel gauge IC maps the cliff correctly and the shutdowns stop.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43405105561690,"sku":"BWCS-NK4DXL-1","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43405105594458,"sku":"BWCS-NK4DXL-2","price":25.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43405105627226,"sku":"BWCS-NK4DXL-3","price":27.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-NK4DXL-1.webp?v=1779369970","url":"https:\/\/batteryweb.com\/products\/blu-hero-2-replacement-battery-37v-1200mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}