{"product_id":"zebra-ql420-replacement-battery-74v-3800mah-li-ion","title":"Zebra QL420 Replacement Battery AT16293-1 7.4V 3800mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eZebra QL420 \/ QL420+ Series — 7.4V Li-ion Replacement Battery (AT16293-1)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 7.4V, 3800mAh Li-ion battery replaces part number AT16293-1 in the Zebra QL420, QL420+, and QL420 Plus portable thermal printers. It restores full motor drive voltage to the paper feed and thermal print head. Used across retail, logistics, and healthcare mobile printing deployments.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eQL420 and QL420+ shared platform:\u003c\/strong\u003e\n    Both the QL420 and QL420+ share the same 7.4V battery bay, connector pinout, and BMS handshake protocol — AT16293-1 fits both without modification or adapter.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this battery through charge and discharge on a QL420 unit. The BMS negotiated correctly, the thermal head reached operating temperature without voltage sag, and the paper feed motor drew consistent current across multiple print runs.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-deploy print sequence:\u003c\/strong\u003e\n    After installing, charge to full and run 5 test label prints before putting the unit into service. The feed motor and thermal head together draw a specific current profile — running that sequence lets the BMS record the correct load signature for the new cell.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the QL420 stops printing after sitting in a drawer\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eLi-ion cells self-discharge at roughly 1–2% per month under no-load storage. After several months, the QL420's BMS may read the pack voltage as below its minimum motor drive threshold — typically around 6.4V — and refuse to power the print head or feed motor. The printer may appear to power on but produce no output. Charge the battery fully before testing; if the pack has dropped into deep-discharge territory, use a charger that includes a recovery or trickle pre-charge mode to bring cell voltage back above 3.0V per cell before standard charging resumes.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBluetooth drops mid-print job on QL420\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe QL420's Bluetooth radio shares the same 7.4V supply rail as the thermal head and feed motor. When the battery is low or a cell is degraded, a sudden current draw from the feed motor causes a momentary voltage sag on that rail. The radio drops its connection to prevent a brownout. This shows up as repeated disconnects when printing multi-label batches, not during idle pairing. Check resting cell voltage — if it reads below 7.0V under no load, the pack no longer holds sufficient charge to handle simultaneous radio and motor current demand.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43415998562394,"sku":"BWCS-ZBL420BL-1","price":50.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43415998595162,"sku":"BWCS-ZBL420BL-2","price":58.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43415998627930,"sku":"BWCS-ZBL420BL-3","price":65.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-ZBL420BL-1.webp?v=1779759122","url":"https:\/\/batteryweb.com\/products\/zebra-ql420-replacement-battery-74v-3800mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}