{"product_id":"kenwood-nx-p500-replacement-battery-36v-2350mah-li-ion","title":"Kenwood NX-P500 KNB-81L Compatible Battery 3.6V 2350mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eKenwood NX-P500 \/ PKT-300 \/ TK-3601D — 3.6V Li-ion Replacement Battery (KNB-81L)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.6V, 2350mAh Li-ion replacement battery for the Kenwood NX-P500, PKT-300, and TK-3601D two-way radios. It replaces OEM part numbers KNB-81L and KNB-81LI. Capacity is sourced from product data at 2350mAh (8.46Wh) — do not use third-party capacity claims.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eNX-P500, PKT-300, TK-3601D platform fit:\u003c\/strong\u003e\n    These three models share the same 3.6V single-cell Li-ion architecture, identical battery bay dimensions (56.80 × 34.40 × 10.80mm), and the same BMS handshake protocol. One battery SKU covers all three 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 charge and discharge on the NX-P500 platform. The BMS accepted the dock handshake on first insertion, held voltage within spec under PTT-triggered transmit loads, and did not trip overcurrent cutoff during sustained RF output bursts.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst insertion on the Kenwood dock:\u003c\/strong\u003e\n    If the charger shows a fault LED on first seating, remove the pack, wipe the gold contact strip with a dry cloth, and reseat firmly. The Kenwood dock requires a clean contact cycle to complete the BMS handshake before charging begins — this is a contact issue, not a pack fault.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the NX-P500 cuts out mid-transmission on a fresh KNB-81L\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe NX-P500 draws a sharp current spike the moment PTT is pressed — transmit current can exceed standby draw by a factor of five or more in the first milliseconds. A new pack sitting at storage voltage (typically around 3.6–3.7V) has not yet been conditioned, and the BMS may interpret this spike as an overcurrent event and trip. The fix is one full charge cycle before first operational use. After that initial cycle, the BMS recalibrates its overcurrent threshold against the actual cell's internal resistance and the cutout stops.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBar indicator showing one fewer bar than expected after fitting the KNB-81L\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe NX-P500 uses a voltage-threshold bar indicator — each bar maps to a fixed voltage band. A new cell shipped at storage voltage (around 3.6V) sits at or near the boundary between bar levels, so the radio may display one bar fewer than expected immediately after fitting. This is not a capacity fault. Charge the pack fully in the dock until the charge LED goes green, then power on the radio — the indicator will reflect the correct resting voltage of approximately 4.1–4.2V and display the expected bar count.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43426167750746,"sku":"BWCS-KNB810TH-1","price":43.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43426167783514,"sku":"BWCS-KNB810TH-2","price":51.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43426167816282,"sku":"BWCS-KNB810TH-3","price":56.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-KNB810TH_1.webp?v=1779930437","url":"https:\/\/batteryweb.com\/products\/kenwood-nx-p500-replacement-battery-36v-2350mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}