{"product_id":"eads-thr9-replacement-battery-37v-5200mah-li-ion","title":"EADS THR9 Replacement Battery BLN-5i 3.7V 5200mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eEADS THR9 \/ THR9i Series — 3.7V Li-ion Replacement Battery (BLN-5i \/ BLN-6)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3.7V, 5200mAh Li-ion battery replaces the BLN-5i and BLN-6 packs used in the EADS THR9, THR9i, and THR9 C-30 portable radios. These are TETRA-capable land mobile radios used in professional and public safety communications. Voltage and capacity match the original spec exactly — 3.7V nominal, 19.24Wh.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eTHR9 \/ THR9i \/ THR9 C-30 platform fit:\u003c\/strong\u003e\n    All three models share the same battery bay geometry, contact layout, and BMS handshake protocol — which is why a single cell covers the whole series. The BLN-5i and BLN-6 are interchangeable across these variants.\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-discharge cycle on the THR9 platform. The BMS responded correctly to charge termination, and transmit current draw during PTT did not trigger overcurrent cutoff at any point in the cycle.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst insertion into the THR9 dock:\u003c\/strong\u003e\n    If the dock shows a fault LED on first insertion, remove the battery and wipe the gold contact strip with a dry cloth before reseating. The THR9 charging dock requires a clean contact cycle to complete the BMS handshake — a single wipe and firm reseat clears this in most cases.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the THR9 drops to reduced TX power mid-shift on a new battery\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eTETRA radios like the THR9 draw a sharp current spike at the start of each transmission slot. If the cell is at storage voltage rather than a full charge — common with new stock — the voltage sag under that spike can push below the radio's TX power threshold. The radio doesn't shut off; it steps down output power to stay within the voltage window. A full charge cycle before first use brings the cell to 4.2V and eliminates this sag margin problem.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBar indicator shows one fewer bar than expected after fitting new BLN-5i\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe THR9 uses a voltage-threshold bar indicator — it reads the cell voltage and maps it to a bar level, with no fuel gauge IC involved. A new cell shipped at storage voltage (typically 3.6–3.8V) will display one bar fewer than a fully charged pack. This is not a cell fault. Charge the battery fully in the dock until the indicator goes green, then reinsert — the bar count will reflect the correct 4.2V terminal voltage.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43426298265690,"sku":"BWCS-ETH910TW-1","price":42.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43426298298458,"sku":"BWCS-ETH910TW-2","price":49.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43426298331226,"sku":"BWCS-ETH910TW-3","price":54.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-ETH910TW-1.webp?v=1779930583","url":"https:\/\/batteryweb.com\/products\/eads-thr9-replacement-battery-37v-5200mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}