{"product_id":"eufy-t8140r-replacement-battery-37v-10400mah-li-ion","title":"Eufy T8140R Compatible Battery 3.7V 10400mAh Li-ion","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eEufy T8140R \/ Cam 2 Pro — 3.7V Li-ion Replacement Battery (1INR19\/66-4)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V Li-ion 18650 cell rated at 10400mAh (38.48Wh), built to replace the original battery in the Eufy T8140R and Cam 2 Pro wireless security cameras. Both cameras run on the same 1INR19\/66-4 cell format with identical connector and BMS handshake requirements. Swap this in when the original cell no longer holds a charge or the camera stops staying online.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eT8140R and Cam 2 Pro compatibility:\u003c\/strong\u003e\n    Both models use the same 18650 cell format, 3.7V nominal rail, and the same BMS communication protocol. The physical footprint — 67.00 x 38.80 x 37.00mm — matches the battery compartment on both 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 motion-trigger cycles, sustained IR LED draw, and WiFi reconnect events. The BMS held voltage above the cutoff threshold across all three load spikes without tripping into protection mode.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-install power cycle:\u003c\/strong\u003e\n    After inserting the battery, power cycle the camera once through the Eufy app. The firmware must register the new cell before motion events log correctly to cloud storage — skipping this step causes missed clips even when the camera appears online.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCamera going offline in the app after battery installation\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eReplacing the battery clears the camera's active session token. The Eufy app loses its authenticated link to the device even though the camera has power. This is not a faulty battery — it is a firmware re-registration event. Open the Eufy app, remove the camera from your device list, and re-add it. The camera will reconnect and resume normal recording.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eApp reporting 0% or incorrect charge percentage after swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eEufy cameras use a voltage-threshold indicator, not a fuel gauge IC. After a battery swap, the firmware has no baseline reference and defaults to 0% or an inaccurate reading. Run the camera through one full charge cycle — charge to 100%, allow normal use until the app shows a low-battery alert, then charge fully again. After that cycle, the voltage thresholds recalibrate and the percentage display tracks correctly.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43377756504154,"sku":"BWCS-EFT814SL-1","price":50.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43377756536922,"sku":"BWCS-EFT814SL-2","price":59.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43377756569690,"sku":"BWCS-EFT814SL-3","price":66.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-EFT814SL-1.webp?v=1778771922","url":"https:\/\/batteryweb.com\/products\/eufy-t8140r-replacement-battery-37v-10400mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}