{"product_id":"vertex-standard-d281-replacement-battery-74v-1800mah-li-ion","title":"Vertex Standard D281 FNB-Z182 Compatible Battery 7.4V 1800mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eVertex Standard D281 \/ VX-D281 — 7.4V Li-ion Replacement Battery (FNB-Z182)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 7.4V, 1800mAh Li-ion replacement battery for the Vertex Standard D281 and VX-D281 two-way radios. It replaces OEM part numbers FNB-Z182 and FNB-Z182ZI. The battery slots into the same housing footprint as the original and uses the same contact layout.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eD281 and VX-D281 platform fit:\u003c\/strong\u003e\n    Both model variants share the same battery bay dimensions, contact pin arrangement, and BMS handshake protocol — one pack covers both. The 7.4V nominal rail matches what the radio's power management circuit expects at startup and during transmit.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this pack on a D281 unit and logged the BMS response through PTT key-up events. The overcurrent protection triggered correctly at the transmit current spike and reset without faulting the radio's power circuit.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst insertion into the charger dock:\u003c\/strong\u003e\n    If the dock LED holds on amber or blinks fault on first seating, remove the battery, wipe the gold contact strip with a dry cloth, and reseat firmly. The Vertex Standard dock requires a clean contact cycle to complete the BMS handshake before it will begin charging.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the D281 drops to reduced TX power mid-shift on a new pack\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eNew Li-ion cells ship at storage voltage — typically 3.6–3.7V per cell — not at full charge. The D281 monitors the battery voltage rail continuously and steps down transmit power when voltage falls below its internal threshold. A pack that starts at storage voltage will hit that threshold earlier in the shift than a fully charged one. Fully charge the battery in the dock before the first use to bring both cells to 4.2V and avoid this voltage sag mid-transmission.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBar indicator showing one fewer bar than expected after fitting the FNB-Z182\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe D281 reads battery level using voltage-threshold steps, not a dedicated fuel gauge chip. A new pack at storage voltage will register one or two bars even though the cell capacity is intact. This is a voltage reading, not a capacity fault. Charge the battery fully — the dock LED will go green — then reinsert into the radio and the bar indicator will reflect the actual state of charge correctly.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43426302820442,"sku":"BWCS-MTD288TW-1","price":44.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43426302853210,"sku":"BWCS-MTD288TW-2","price":51.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43426302885978,"sku":"BWCS-MTD288TW-3","price":57.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-MTD288TW-1.webp?v=1779930602","url":"https:\/\/batteryweb.com\/products\/vertex-standard-d281-replacement-battery-74v-1800mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}