{"product_id":"yaesu-vx-820-replacement-battery-72v-2600mah-li-ion","title":"Yaesu FNB-V86LI VX-820 Replacement Battery 7.2V 2600mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eYaesu VX-820 \/ VX-821 \/ VX-824 \/ VX-829 — 7.2V Li-ion Replacement Battery (FNB-V86LI \/ FNB-V87LI)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 7.2V 2600mAh lithium-ion replacement battery for the Yaesu VX-820, VX-821, VX-824, and VX-829 portable transceivers. It replaces OEM part numbers FNB-V86LI and FNB-V87LI. The pack slots directly into the radio's battery compartment and engages the same contact array as the original.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eVX-820 series shared battery platform:\u003c\/strong\u003e\n    The VX-820, VX-821, VX-824, and VX-829 all run the same 7.2V battery rail and use an identical four-contact connector with the same BMS handshake protocol — one pack covers the full series 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 PTT transmit loads on the VX-820 and confirmed the BMS held steady through repeated high-current spikes without tripping into overcurrent lockout. Charge acceptance was clean on the standard desktop charger from the first cycle.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst insertion into the charger dock:\u003c\/strong\u003e\n    If the dock shows a fault LED on first insertion, remove the pack and wipe the gold contact strip with a dry cloth before reseating. The VX-series charger 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 VX-820 cuts out mid-transmission on a new FNB-V86LI\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eA new cell ships at storage voltage — typically around 3.6–3.7V per cell — not at full charge. When you key up on a full-power transmission, the radio draws a sharp current spike that can push the BMS into a momentary undervoltage trip if the pack hasn't been charged first. The radio goes silent mid-PTT, and the display may flicker before recovering. Charge the pack fully before first field use and the BMS will have enough headroom to absorb that transmit surge without tripping.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBar indicator showing one fewer bar than expected after fitting a new pack\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe VX-820 reads battery level from raw terminal voltage, not a charge counter. A new pack at storage voltage reads lower than a freshly charged one, so the radio displays one fewer bar even though the cells are healthy. This is not a fault with the pack. Charge the battery fully in the desktop dock, let it cool for ten minutes, then reinsert — the indicator should show all bars at a resting voltage of approximately 8.2–8.4V.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43426332115034,"sku":"BWCS-FNB87TW-1","price":40.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43426332147802,"sku":"BWCS-FNB87TW-2","price":46.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43426332180570,"sku":"BWCS-FNB87TW-3","price":51.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-FNB87TW-1.webp?v=1779930720","url":"https:\/\/batteryweb.com\/products\/yaesu-vx-820-replacement-battery-72v-2600mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}