{"product_id":"vertex-standard-vx-820-replacement-battery-72v-2600mah-li-ion","title":"Vertex Standard VX-820 Compatible Battery FNB-V86LI 7.2V 2600mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eVertex Standard VX-820 \/ VX-824 Series — 7.2V Li-ion Replacement Battery (FNB-V86LI)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 7.2V, 2600mAh lithium-ion battery for the Vertex Standard VX-820, VX-821, VX-824, and VX-829 portable two-way radios. It replaces OEM part numbers FNB-V86LI, FNB-V87LI, and FNB-V86. The battery mounts and latches using the same housing geometry as the original pack.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eVX-820 series platform fit:\u003c\/strong\u003e\n    The VX-820, VX-821, VX-824, and VX-829 share the same 7.2V rail, battery latch, and contact pin layout. One pack covers all four models because Vertex Standard held that hardware constant across the series.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this pack through a full charge cycle and verified the BMS handshake with the standard Vertex charger dock. The protection circuit tripped correctly at the expected current thresholds during transmit-load simulation.\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, wipe the gold contact strip with a dry cloth, and reseat firmly. The Vertex platform requires a clean contact cycle before the dock accepts a new BMS and begins 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 freshly inserted battery\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003ePressing PTT on the VX-820 draws a sharp current spike as the RF output stage ramps to full power. If the battery shipped at storage voltage — typically 3.6–3.7V per cell — the BMS may read that spike as an overcurrent event and momentarily cut the output. This is not a faulty pack. Placing the battery in the charger for at least one full charge cycle before use brings cell voltage up to the threshold where the BMS handles transmit spikes without tripping.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBar indicator showing one fewer bar than expected on a new pack\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe VX-820 reads battery level from cell voltage alone — it has no capacity-tracking circuit. A new pack at storage voltage sits below the top voltage threshold, so the radio displays one bar fewer than a fully charged cell. This is a voltage reading, not a sign the pack is weak or undersized. Charge the battery fully in the dock first; once cell voltage reaches approximately 8.4V, the indicator will show correctly.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43426332311642,"sku":"BWCS-FNB87TW-1","price":40.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43426332344410,"sku":"BWCS-FNB87TW-2","price":46.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43426332377178,"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\/vertex-standard-vx-820-replacement-battery-72v-2600mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}