{"product_id":"thorn-voyager-twinspot-replacement-battery-48v-4000mah-ni-cd","title":"Thorn Voyager TwinSpot 4.8V 4000mAh Ni-CD Replacement Battery","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eThorn Voyager TwinSpot — 4.8V Ni-CD Replacement Battery (4VTD70 787296)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 4.8V 4000mAh Ni-CD battery for the Thorn Voyager TwinSpot emergency lighting fixture. It provides backup power during mains failure, keeping the twin-spot heads active for safe evacuation lighting. The OEM references for this cell are 4VTD70 787296 and 621-0792.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eVoyager TwinSpot platform fit:\u003c\/strong\u003e\n    The TwinSpot uses a dedicated 4.8V Ni-CD cell block that connects directly to the onboard charge controller. The cell voltage, connector orientation, and physical dimensions (130 × 62 × 32.90mm) match the original housing without modification.\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 load discharge on the TwinSpot controller. The BMS accepted the cell voltage on first connection, the charge indicator transitioned correctly, and the cell delivered rated capacity without thermal event.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle conditioning for compliance testing:\u003c\/strong\u003e\n    Run a full manual test within 24 hours of installation by holding the test button for the complete rated duration. This confirms the new cell accepts load under real conditions and lets the charge controller register cell capacity before the next scheduled compliance inspection.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the TwinSpot charge controller rejects a new cell straight out of the packaging\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eNi-CD cells self-discharge during storage. By the time a replacement arrives, its resting voltage may sit below the float acceptance threshold of the TwinSpot charge controller — typically around 4.2–4.5V for a discharged 4.8V pack. The controller interprets this as a fault condition rather than a fresh cell needing charge. Leave the fitting powered with mains for 12–24 hours before testing. The controller will top-charge the cell into its acceptance window and clear the fault state on its own.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eEmergency light dims noticeably partway through a duration test\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis is a first-activation issue, not a cell defect. A Ni-CD cell that has not completed one full charge cycle from storage cannot sustain rated discharge current for the full test duration — voltage sags early under the twin-spot lamp load. The fix is a full 24-hour mains charge before the test. If dimming persists after one complete charge cycle, measure the resting voltage across the cell terminals: a fully charged 4.8V Ni-CD pack should read above 5.6V open circuit.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43360353648730,"sku":"BWCS-LPN400LS-1","price":58.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43360353681498,"sku":"BWCS-LPN400LS-2","price":68.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43360353714266,"sku":"BWCS-LPN400LS-3","price":75.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-LPN400LS-1.webp?v=1778611162","url":"https:\/\/batteryweb.com\/products\/thorn-voyager-twinspot-replacement-battery-48v-4000mah-ni-cd","provider":"BatteryWeb","version":"1.0","type":"link"}