{"product_id":"kosnic-uem03-replacement-battery-37v-5000mah-li-ion","title":"Kosnic BAT48LI1 Emergency Light Replacement Battery 3.7V 5000mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eKosnic UEM03 \/ UEM Pro Universal Emergency Module — 3.7V Li-ion Replacement Battery (BAT48LI1)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V 5000mAh Li-ion replacement cell for the Kosnic UEM03 and UEM Pro Universal Emergency Module. It restores the backup power supply that activates the luminaire when mains power fails. At 18.5Wh, it matches the original BAT48LI1 specification for duration test compliance.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eUEM03 and UEM Pro compatibility:\u003c\/strong\u003e\n    Both units share the same BAT48LI1 cell format, charge controller voltage rail at 3.7V nominal, and connector footprint. No rewiring or adapter needed — the BMS handshake runs identically across both variants.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through a full charge and simulated mains-fail discharge on the UEM Pro charge board. The BMS accepted load at 3.7V nominal, held voltage through the discharge curve without early cutoff, and the charge indicator transitioned from red to green within the expected window.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-installation test cycle:\u003c\/strong\u003e\n    Within 24 hours of fitting, hold the test button for the full rated duration. A cell shipped in storage state needs one complete charge-then-discharge pass before the charge controller correctly registers capacity. Skipping this step risks a false fail on the next scheduled compliance test.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eEmergency light failing its duration test after battery replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA freshly installed BAT48LI1 cell arrives partially discharged from warehouse storage — typically between 3.3V and 3.5V. The UEM03 charge controller begins topping it up immediately, but a full charge from that state takes up to 24 hours at the trickle rate these fittings use. If a compliance test is run before the cell reaches 3.7V float, the luminaire will dim or cut out before the rated duration. Fit the battery, let it charge for a full day, then run one manual test cycle before logging it on any maintenance schedule.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCharge indicator staying red after new battery installation\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe UEM03 charge controller uses the incoming cell voltage to decide whether to enter float or bulk charge mode. A cell sitting below roughly 3.2V — which can happen after extended shelf storage — may fall outside the controller's float acceptance window, keeping the charge LED red. This is not a fault with the cell or the fitting. Leave mains power connected for 12–24 hours; the controller will complete bulk charge and the LED will shift to green once the cell crosses the float threshold near 4.1–4.2V.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43360301318234,"sku":"BWCS-KUP481LS-1","price":43.99,"currency_code":"USD","in_stock":false},{"title":"Warranty 2 Year","offer_id":43360301351002,"sku":"BWCS-KUP481LS-2","price":51.99,"currency_code":"USD","in_stock":false},{"title":"Warranty 3 Year","offer_id":43360301383770,"sku":"BWCS-KUP481LS-3","price":56.99,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-KUP481LS_1.webp?v=1778611049","url":"https:\/\/batteryweb.com\/products\/kosnic-uem03-replacement-battery-37v-5000mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}