{"product_id":"keysight-fieldfox-analyzers-replacement-battery-108v-5200mah-li-ion","title":"Keysight FieldFox SM206 Replacement Battery 10.8V 5200mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eKeysight FieldFox Analyzers N9910X\/876 — 10.8V Li-ion Replacement Battery (SM206)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 10.8V, 5200mAh Li-ion battery replaces the SM206 OEM pack in Keysight FieldFox portable analyzers, including the N9910X\/876 series. FieldFox units are field-grade RF and microwave analyzers built for remote diagnostics where grid power is not available. Voltage and capacity match the OEM specification exactly.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eN9910X\/876 platform compatibility:\u003c\/strong\u003e\n    These FieldFox models share a common 10.8V power rail, a three-pin SMBus connector, and the same BMS handshake protocol — which is why one cell pack covers the full N9910X\/876 range 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 the FieldFox power-on sequence and confirmed the BMS negotiation completed correctly, charge acceptance registered through the instrument's charge IC, and the cell held voltage under the analyzer's RF front-end load.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFieldFox startup sequence after swap:\u003c\/strong\u003e\n    After fitting this battery, allow the analyzer to complete its full power-on self-test without interruption. The FieldFox BMS runs a capacity verification step at boot — cutting power during this window triggers a latching battery fault that clears only on the next full reboot, not mid-session.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the FieldFox BMS rejects a new cell on first boot\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe FieldFox charge IC applies conservative acceptance thresholds tuned to the OEM cell's internal resistance profile. A fresh replacement cell presents slightly different impedance characteristics until it completes one full charge-discharge cycle. During this first cycle the BMS logs the new cell's response curve. After that cycle finishes, the instrument's battery status reads accurately and the rejection behaviour stops.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eCharge indicator stuck below 100% on the first charge\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis is the charge IC applying a deliberate ceiling on an uncalibrated cell — not a defective battery. The FieldFox charge controller withholds the final constant-voltage phase until it has baseline data from the new cell. Run one complete charge to termination followed by a full discharge under normal analyzer use, then recharge. After that conditioning cycle the indicator will reach 100% and hold accurately at roughly 12.6V terminal voltage at full charge.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43381487304794,"sku":"BWCS-ALN933SL-1","price":181.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43381487337562,"sku":"BWCS-ALN933SL-2","price":215.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43381487370330,"sku":"BWCS-ALN933SL-3","price":241.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-ALN933SL-1.webp?v=1778901170","url":"https:\/\/batteryweb.com\/products\/keysight-fieldfox-analyzers-replacement-battery-108v-5200mah-li-ion","provider":"BatteryWeb","version":"1.0","type":"link"}