{"product_id":"nikon-1-j1-replacement-battery-74v-850mah-li-ion","title":"NiKon EN-EL20 Replacement Battery 7.4V 850mAh Li-ion","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eNiKon 1 J1 \/ 1 J2 \/ 1 J3 \/ Coolpix A — 7.4V Li-ion Replacement Battery (EN-EL20)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 7.4V, 850mAh Li-ion cell built to the EN-EL20 \/ EN-EL20a specification. It fits the NiKon 1 J1, 1 J2, 1 J3, and Coolpix A mirrorless cameras, along with five additional compatible bodies. The battery powers the camera's sensor, autofocus motor, and image processing unit.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003e1-series and Coolpix A compatibility:\u003c\/strong\u003e\n    These bodies share the same EN-EL20 form factor, contact pinout, and BMS handshake protocol. One cell covers the full list — no hardware differences between variants.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through the 1 J1 body and monitored BMS communication across charge and discharge. The protection circuit responded correctly to cutoff thresholds and the body accepted the cell without error flags on repeated insertion.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle charge protocol:\u003c\/strong\u003e\n    Run the first full charge from inside the camera body using the OEM MH-27 charger or USB body-charge if supported. Some NiKon BMS builds require one internal charge cycle before the battery-remaining indicator maps correctly to the new cell's discharge curve.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the 1 J1 battery indicator reads full then drops sharply mid-shoot\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe 1 J1 maps remaining charge by reading cell voltage against a stored discharge curve from the original NiKon cell. A new third-party cell has a slightly different voltage-to-capacity curve, so the indicator can read optimistic at the top of the charge then fall steeply once voltage drops past the camera's first threshold point. This is a calibration lag in the BMS, not a cell fault. After one or two full charge-discharge cycles through the camera body, the indicator tracking stabilises and becomes consistent.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCamera displaying \"no battery\" on a charged replacement cell at first insert\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe 1-series body runs an authentication check on every new cell at insertion. If the BMS has not yet completed a full charge handshake with the replacement cell, it can flag the cell as unrecognised even when the cell carries a charge. The fix is straightforward: insert the cell, place the camera on charge via the MH-27 charger, and allow a full charge cycle to complete. Once the handshake completes, the body accepts the cell and the error clears — typically resolved at 8.4V full-charge state.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43333804261466,"sku":"BWCS-ENEL20-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43333804294234,"sku":"BWCS-ENEL20-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43333804327002,"sku":"BWCS-ENEL20-3","price":29.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-ENEL20-1.webp?v=1778213127","url":"https:\/\/batteryweb.com\/products\/nikon-1-j1-replacement-battery-74v-850mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}