{"product_id":"sony-action-cam-mini-az1-replacement-battery-37v-640mah-li-ion","title":"Sony NP-BY1 Action Cam Compatible Battery 3.7V 640mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eSony Action Cam Mini AZ1 \/ HDR-AZ1 Series — 3.7V Li-ion Replacement Battery (NP-BY1)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V, 640mAh (2.37Wh) Li-ion cell built to the NP-BY1 specification. It fits the Sony Action Cam Mini AZ1, HDR-AZ1, HDR-AZ1\/W, and HDR-AZ1VR. The cell matches the original's footprint exactly at 38.20 × 26.82 × 7.34mm, so it seats and locks without modification.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eAZ1 series compatibility:\u003c\/strong\u003e\n    The HDR-AZ1 family shares a single battery bay spec — same voltage rail, same lock tab position, same BMS handshake protocol across all variants. One cell works across the full lineup listed above.\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 an HDR-AZ1 body. The BMS accepted the cell on first install, reported state-of-charge without error, and held the protection circuit cutoff at the correct low-voltage threshold.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle initialisation on the AZ1:\u003c\/strong\u003e\n    The AZ1's battery indicator can misread a new cell if you pull it mid-charge. Run the first charge to 100% uninterrupted — either in the camera body or the BC-BY1 charger — before shooting. This lets the BMS map the cell's discharge curve accurately from the start.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the AZ1 rejects a third-party cell on first install\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eSony's AZ1 BMS runs a voltage-window check the moment a battery seats. If the cell arrives at the camera below roughly 3.0V — common after extended warehouse storage — the body flags it as unreadable and shows a blinking battery icon. This is not a compatibility fault. Place the cell in the BC-BY1 external charger first and bring it to full charge before inserting it into the camera. Once the BMS sees the cell enter from a known-good voltage, it accepts and tracks it normally on every subsequent cycle.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBattery percentage jumping erratically on the AZ1 display\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe AZ1 maps remaining capacity using voltage thresholds calibrated to Sony's original NP-BY1 discharge curve. A new replacement cell — even a spec-matched one — can show percentage jumps of 20–30% between readings until the camera's BMS has logged one or two full charge-discharge cycles. The cause is a mismatch between the camera's expected voltage steps and the actual curve of the new cell. Run two full cycles from 100% charge to automatic shutoff and the indicator stabilises.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43333718835290,"sku":"BWCS-SAZ100MC-1","price":22.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43333718868058,"sku":"BWCS-SAZ100MC-2","price":25.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43333718900826,"sku":"BWCS-SAZ100MC-3","price":27.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-SAZ100MC_1.webp?v=1778213084","url":"https:\/\/batteryweb.com\/products\/sony-action-cam-mini-az1-replacement-battery-37v-640mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}