{"product_id":"barnes-noble-nook-hd-7-tablet-replacement-battery-37v-4000mah-li-polymer","title":"Barnes \u0026 Noble NOOK HD 7 Replacement Battery BNA-B0002 3.7V 4000mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eBarnes \u0026amp; Noble NOOK HD 7 (BNRV400 \/ BNTV400) — 3.7V Li-Polymer Replacement Battery (BNA-B0002)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V 4000mAh lithium-polymer battery for the Barnes \u0026amp; Noble NOOK HD 7 tablet. It fits the BNRV400 and BNTV400 model numbers and replaces OEM part BNA-B0002 and L83-4977-266-01-4. Swap this in when the original cell no longer holds charge or the tablet shuts down unexpectedly under load.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eBNRV400 and BNTV400 compatibility:\u003c\/strong\u003e\n    Both model codes refer to the same NOOK HD 7 hardware platform. They share an identical battery bay, connector pinout, and charge IC handshake, so one part number covers 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 NOOK HD 7 platform. The BMS accepted the charge profile without fault codes, and voltage held steady across display-on and Wi-Fi-active load states.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge reset after installation:\u003c\/strong\u003e\n    After fitting this battery, run the tablet down to automatic shutoff, then charge uninterrupted to 100%. This forces the fuel gauge IC to recalibrate against the new cell and eliminates the inaccurate percentage readings that commonly appear after a swap.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eNOOK HD 7 shutting down at 15–25% remaining\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe NOOK HD 7 combines a power-hungry 7-inch IPS display with active Wi-Fi into a relatively narrow voltage window. When the cell ages, voltage sags faster than the fuel gauge tracks — the tablet reads 20% but the cell voltage has already dropped below the BMS cutoff threshold. This is a cell-level problem, not a software fault. Fitting a fresh 4000mAh cell restores the flat discharge curve and pushes the real cutoff back below 5%. After the swap, run one full recalibration cycle so the fuel gauge IC maps the new voltage curve correctly.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eTablet showing 100% charge but losing percentage within minutes of unplugging\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis is fuel gauge drift — the charge IC is reporting state-of-charge based on a calibration curve built around the old, degraded cell. The new cell has a different internal resistance and capacity profile, so the reported percentage detaches from actual charge state almost immediately. It is not a fault in the replacement battery. Discharge the tablet completely to auto-shutoff, then charge in one uninterrupted session to 100% at the standard 5V USB rate — this resets the calibration and the percentage display will track correctly from that point.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43426048639066,"sku":"BWCS-BNR007SL-1","price":30.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43426048671834,"sku":"BWCS-BNR007SL-2","price":35.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43426048704602,"sku":"BWCS-BNR007SL-3","price":38.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-BNR007SL-1.webp?v=1779930196","url":"https:\/\/batteryweb.com\/products\/barnes-noble-nook-hd-7-tablet-replacement-battery-37v-4000mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}