{"product_id":"zoom-q4-replacement-battery-37v-1050mah-li-ion","title":"Zoom Q4 Replacement Battery BT-02 3.7V 1050mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eZoom Q4 Handy Video Recorder — 3.7V Li-ion Replacement Battery (BT-02)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3.7V, 1050mAh lithium-ion cell replaces the OEM BT-02 battery in the Zoom Q4 Handy Video Recorder. It fits the Q4 and Q4-series units (including 247-9036) used for field audio and video capture. Dimensions are 43.30 × 31.30 × 7.10mm — match these before fitting if you are unsure of your unit revision.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eQ4 and Q4 Handy Video Recorder compatibility:\u003c\/strong\u003e\n    Both models run the same 3.7V single-cell architecture with the BT-02 connector and contact layout. The BMS in each unit reads the same voltage thresholds, so one cell covers both variants without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell through charge and discharge cycles on Q4 hardware. The BMS accepted the cell without error flags, completed a full charge without thermal cutoff, and the recorder powered on normally at each stage of the discharge curve.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle conditioning on the Q4:\u003c\/strong\u003e\n    Charge this cell fully inside the Q4 body before your first recording session. The Q4's battery-remaining indicator calibrates its threshold map during the first in-body charge cycle — skipping this step can cause the indicator to report inaccurate levels until a full cycle is completed.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eQ4 battery indicator dropping to zero before the cell is actually flat\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe Q4 maps its battery-remaining display against a fixed voltage-threshold curve calibrated to the original BT-02's discharge profile. A replacement cell with a slightly different discharge curve can cause the indicator to hit zero while the cell still holds usable charge. This is a display mapping issue, not a cell fault. Run the recorder until it shuts down on its own, then charge fully in the body — one complete cycle usually brings the indicator back into step with actual capacity.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eQ4 not recognising the replacement cell on first install\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eIf the Q4 powers on but immediately displays a low-battery warning or shuts down after inserting a new cell, the BMS has not yet accepted the replacement. Remove the cell, reinsert it firmly, and connect the recorder to its charger before powering on. Allow a full charge cycle to complete from within the body. After that cycle, the unit should recognise the cell and resume normal operation at 3.7V nominal.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43333704646746,"sku":"BWCS-ZM400MC-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43333704679514,"sku":"BWCS-ZM400MC-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43333704712282,"sku":"BWCS-ZM400MC-3","price":29.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-ZM400MC-1.webp?v=1778213032","url":"https:\/\/batteryweb.com\/products\/zoom-q4-replacement-battery-37v-1050mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}