{"product_id":"standard-horizon-hx280s-replacement-battery-74v-1800mah-li-ion","title":"Standard Horizon HX280S Replacement Battery 7.4V 1800mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eStandard Horizon HX280S Series — 7.4V Li-ion Replacement Battery (FNB-V105Li)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 7.4V, 1800mAh Li-ion replacement for the FNB-V105Li battery pack. It fits the Standard Horizon HX280S, HX280, HX280E, and HX380 handheld VHF marine radios. Same voltage, same connector, same BMS handshake protocol as the original.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eHX280S, HX280, HX280E, HX380 compatibility:\u003c\/strong\u003e\n    These four models share the same battery bay geometry, 7.4V rail, and contact pinout. The FNB-V105Li BMS communicates directly with the radio's charge controller — swapping packs across these models works without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this pack through full charge and discharge on an HX280S dock. The BMS held stable under PTT transmit loads and tripped cleanly at low-voltage threshold without locking out the radio's charge circuit.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eContact strip care on first dock insertion:\u003c\/strong\u003e\n    If the dock shows a fault LED on first insertion, remove the pack, wipe the gold contact strip with a dry cloth, and reseat firmly. The Standard Horizon charge controller requires a clean contact cycle to register the new BMS before charging begins.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the HX280S drops transmit power mid-call on a new FNB-V105Li\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe HX280S draws a sharp current spike the moment PTT is pressed — marine VHF transmit loads hit around 1.5A. A new cell shipped at storage voltage (roughly 3.7V per cell) has higher internal impedance than a fully charged cell. That impedance causes a voltage sag under the transmit spike, and the radio's BMS interprets it as a low-voltage condition. One full charge cycle to 8.4V brings impedance down and eliminates the drop.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBar indicator showing one fewer bar than expected after installing FNB-V105Li\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe HX280S uses a simple voltage-threshold bar indicator — each bar maps to a fixed voltage band, not a charge percentage. Fresh packs ship at storage voltage, which sits in the second bar's threshold range. This is not a capacity fault. Charge the pack fully in the dock until the charge LED goes green, then power the radio on — the indicator will read correctly at full charge voltage.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43426296365146,"sku":"BWCS-VRX280TW-1","price":40.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43426296397914,"sku":"BWCS-VRX280TW-2","price":46.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43426296430682,"sku":"BWCS-VRX280TW-3","price":51.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-VRX280TW-1.webp?v=1779930602","url":"https:\/\/batteryweb.com\/products\/standard-horizon-hx280s-replacement-battery-74v-1800mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}