{"product_id":"kenwood-tk-250-replacement-battery-72v-1200mah-ni-mh","title":"Kenwood KNB-9A TK-250 Replacement Battery 7.2V 1200mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eKenwood TK-250 \/ TK-255 Series — 7.2V Ni-MH Replacement Battery (KNB-9A)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 7.2V, 1200mAh Ni-MH replacement battery for the Kenwood TK-250, TK-250G, TK-255, and TK-259 portable two-way radios. It replaces OEM part numbers KNB-9A, KNB-11, KNB-11A, KNB-11N, KNB-12, KNB-12A, KNB-18A, and KNB-19A. The pack slots into the same battery bay and connects via the same multi-pin contact strip as the original.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eTK-250 and TK-255 series fit:\u003c\/strong\u003e\n    These models share a common battery bay geometry and 7.2V voltage rail. The BMS handshake protocol and connector pinout are identical across the KNB-9A through KNB-19A family, which is why one pack covers multiple part numbers in this lineup.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this pack through transmit loads on the TK-250 platform. The BMS handled the PTT current spike without tripping overcurrent cutoff, and the voltage held stable across sustained RF output.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst insertion into the dock:\u003c\/strong\u003e\n    If the charger shows a fault LED on first insertion, remove the pack, wipe the gold contact strip with a dry cloth, and reseat it firmly. The Kenwood dock requires a clean contact cycle to complete the BMS handshake before it 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 TK-250 cuts out mid-transmission on a freshly inserted pack\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eNi-MH cells ship at partial storage voltage — typically around 6.0–6.4V for a 7.2V six-cell pack. When PTT is pressed, the transmitter pulls a sharp current spike. If the pack hasn't completed an initial charge cycle, that spike can drag cell voltage below the BMS cutoff threshold momentarily, killing the transmission. This isn't a faulty battery — it's a cell voltage condition. Run one full charge cycle in the Kenwood dock before first use in the field, and the cutout behaviour stops.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBar indicator showing one fewer bar than expected after swapping in this pack\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe TK-250 reads battery status using voltage-threshold detection — it maps resting pack voltage to a bar count on the display. A new Ni-MH pack at storage voltage sits in a lower threshold band than a fully charged one, so the radio correctly reports fewer bars. This is not a capacity or cell defect. Charge the pack fully in the Kenwood dock until the charger LED goes solid green, then reinsert — the indicator will read the correct bar count at or above 7.8V resting voltage.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43426360885338,"sku":"BWCS-KNB120TW-1","price":49.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43426360918106,"sku":"BWCS-KNB120TW-2","price":57.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43426360950874,"sku":"BWCS-KNB120TW-3","price":64.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-KNB120TW-1.webp?v=1779930808","url":"https:\/\/batteryweb.com\/products\/kenwood-tk-250-replacement-battery-72v-1200mah-ni-mh","provider":"BatteryWeb","version":"1.0","type":"link"}