{"product_id":"blu-bar-q-replacement-battery-37v-900mah-li-ion","title":"BLU Bar Q N5B80T Compatible Battery 3.7V 900mAh Li-ion","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eBLU Bar Q — 3.7V Li-ion Replacement Battery (N5B80T)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 900mAh Li-ion replacement battery for the BLU Bar Q mobile phone. It carries OEM part number N5B80T and fits the Bar Q directly. Install it when the original cell no longer holds a charge through a normal day of calls and messaging.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eBar Q compatibility:\u003c\/strong\u003e\n    The Bar Q uses a low-voltage 3.7V single-cell pack with a specific connector pitch and BMS handshake tied to the N5B80T part. Swapping to any other cell risks a BMS rejection at the charge IC, preventing the phone from accepting current at all.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran the N5B80T through charge cycles on a Bar Q unit and monitored BMS communication throughout. The protection circuit engaged correctly at both low-voltage cutoff and over-current thresholds. No false rejection from the phone's charge IC was observed.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first install:\u003c\/strong\u003e\n    On first use after fitting this cell, disable any fast-charging mode and complete one full discharge-charge cycle. The fuel gauge IC on the Bar Q is still calibrated to the old cell's discharge curve. Running one uninterrupted cycle lets the coulomb counter reset against the new cell before reporting accurate percentages.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the Bar Q reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe Bar Q uses a fuel gauge IC that builds its charge model from the previous cell's discharge curve. When a new cell goes in, that stored curve no longer matches the actual chemistry. The IC will over- or under-report state of charge until it has seen at least one complete cycle from 100% down to auto-shutoff and back to full. After that cycle, the percentage readout stabilises against the new cell's actual capacity.\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 fuel gauge IC still holds the old cell's voltage-to-capacity map and the new cell hits a steeper voltage cliff under load. When the modem fires during a call or data burst, current draw spikes and cell voltage drops sharply — faster than the IC predicts. The phone's hardware protection reads that as an imminent under-voltage event and cuts power before the display shows 0%. Complete one full discharge cycle to let the coulomb counter recalibrate, and target a resting cell voltage of around 3.85V before the next full charge.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43405106970714,"sku":"BWCS-NK5BHL-1","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43405107003482,"sku":"BWCS-NK5BHL-2","price":25.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43405107036250,"sku":"BWCS-NK5BHL-3","price":27.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-NK5BHL-1.webp?v=1779369992","url":"https:\/\/batteryweb.com\/products\/blu-bar-q-replacement-battery-37v-900mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}