{"product_id":"nokia-thr850-replacement-battery-37v-2000mah-li-ion","title":"Nokia THR850 Replacement Battery BLN-4 3.7V 2000mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eNokia THR850 Series — 3.7V Li-ion Replacement Battery (BLN-4)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.7V 2000mAh Li-ion battery for the Nokia THR850, THR880, THR880i, and THR880i Light two-way radios. It replaces OEM part numbers BLN-4 and BLN-4D. These radios run on professional land mobile networks and are common in security, construction, and hospitality operations.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eTHR850 and THR880 series compatibility:\u003c\/strong\u003e\n    All four models in this lineup share the same 3.7V battery bay, connector pinout, and BMS handshake protocol. One pack covers the full platform.\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 THR850 bench rig. The BMS held voltage stable under PTT current spikes and re-engaged correctly after each discharge cycle without tripping lockout.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst insertion into the charger dock:\u003c\/strong\u003e\n    If the dock LED shows a fault on first insertion, remove the pack, wipe the gold contact strip with a dry cloth, and reseat firmly. The THR platform requires a clean contact cycle to complete the BMS handshake 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\"\u003eTHR850 dropping to reduced TX power mid-shift on a new BLN-4\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eNew Li-ion cells ship at storage voltage — typically around 3.6V — not at full charge. The THR850 monitors supply voltage continuously and steps down transmit power when the rail drops below its threshold. This is not a faulty pack. Run the battery through one full charge cycle in the dock before putting it into active use. After that first full charge, the radio will operate at rated TX power without stepping down.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBar indicator showing one fewer bar than expected after BLN-4 swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe THR880 series uses a simple voltage-threshold bar indicator — it reads the pack's resting voltage and maps it to bars. A new cell at storage voltage reads lower than a fully charged cell, so the indicator shows one or two bars even on a fresh pack. This is not a capacity defect. Charge the pack fully in the dock until the LED goes green, then reinsert. The indicator will show a full bar reading once the cell sits above 4.1V.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43426373533786,"sku":"BWCS-NKN4SL-1","price":30.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43426373566554,"sku":"BWCS-NKN4SL-2","price":34.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43426373599322,"sku":"BWCS-NKN4SL-3","price":37.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-NKN4SL-1.webp?v=1779931026","url":"https:\/\/batteryweb.com\/products\/nokia-thr850-replacement-battery-37v-2000mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}