{"product_id":"yokogawa-s9548fa-hhr-21ahf2a1-2-4v-1900mah-dcs-battery-unit","title":"Yokogawa S9548FA HHR-21AHF2A1 2.4V 1900mAh DCS Battery Unit","description":"\u003ch2\u003eYokogawa S9548FA Battery Unit\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eYokogawa S9548FA\u003c\/strong\u003e, also cataloged as the \u003cstrong\u003eS9548FA\u003c\/strong\u003e (HHR-21AHF2A1) Battery Unit, operates as a dedicated hardware component for backup power retention and volatile memory preservation within Yokogawa DCS controllers and memory modules. The assembly delivers continuous DC energy to safeguard critical system parameters and system configuration data during main power disruptions.\u003c\/p\u003e\n\u003ch3\u003eHardware Specifications\u003c\/h3\u003e\n\u003cfigure class=\"table\"\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eParameter\u003c\/strong\u003e\u003c\/th\u003e\n\u003cth\u003e\u003cstrong\u003eSpecification\u003c\/strong\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003eS9548FA (HHR-21AHF2A1)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eYokogawa\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOrigin\u003c\/td\u003e\n\u003ctd\u003eJapan\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.02 kg (20 g)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e45 x 20 x 5 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temp\u003c\/td\u003e\n\u003ctd\u003e-20 to 55 deg C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Consumption\u003c\/td\u003e\n\u003ctd\u003ePassive battery backup cell\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eChemistry Type\u003c\/td\u003e\n\u003ctd\u003eNickel-Metal Hydride (Ni-MH)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNominal Voltage\u003c\/td\u003e\n\u003ctd\u003e2.4 VDC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNominal Capacity\u003c\/td\u003e\n\u003ctd\u003e1900 mAh\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery Cell Configuration\u003c\/td\u003e\n\u003ctd\u003e2-cell series pack\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eForm Factor\u003c\/td\u003e\n\u003ctd\u003eInternal DCS memory backup pack\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCertifications\u003c\/td\u003e\n\u003ctd\u003eRoHS, SGS, UN38.3 compliance\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003e4-20 mA HART Loop Protocol \u0026amp; Channel Isolation\u003c\/h3\u003e\n\u003cp\u003eThe S9548FA backup battery pack provides isolated secondary power directly to memory retention circuits inside DCS processor units, maintaining internal system clock operation and volatile register states independently of the 24 VDC main power bus. By maintaining logic memory integrity during emergency shutdown (ESD) events or total line dropouts, the unit prevents loss of calibration parameters, field device mapping tables, and baseline tuning values associated with connected 4-20 mA HART loop protocol instruments. The physical isolation of the battery pack preserves ground reference integrity across processing nodes and prevents stray supply noise from coupling into high-resolution analog measurement circuits.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003eQ: What is the procedure for replacing the S9548FA battery pack without interrupting active DCS system operations?\u003c\/p\u003e\n\u003cp\u003eA: Technicians can safely hot-swap the S9548FA battery pack while the host controller module remains fully energized by primary 24 VDC system power. When main line power is active, the controller draws operating current from the backplane, permitting technical personnel to disconnect the depleted battery assembly and land the replacement pack without losing SRAM contents or real-time system clock synchronization.\u003c\/p\u003e\n\u003cp\u003eQ: What diagnostic indicators or system alerts signal a depleted S9548FA battery?\u003c\/p\u003e\n\u003cp\u003eA: The host Yokogawa DCS module continuously monitors the cell terminal voltage of the S9548FA. When the voltage drops below the minimum logic backup threshold, the processor triggers a system diagnostic alarm on the operator console and illuminates a dedicated BATTERY LOW LED on the module front panel, indicating that maintenance personnel should replace the pack prior to any scheduled maintenance outage.\u003c\/p\u003e\n\u003ch3\u003eField Installation Guidelines\u003c\/h3\u003e\n\u003cp\u003eWhen installing the S9548FA battery pack into a Yokogawa DCS controller or memory module, first inspect the wiring harness and polarized connector plug for physical damage. Carefully align the keying tabs of the connector with the module mating socket to ensure correct polarity before pressing the connector housing firmly into place. Secure the battery casing into its dedicated retaining clip within the module enclosure to prevent mechanical vibration from dislodging the assembly. Handle the battery pack avoiding short-circuiting the exposed terminal pins, and dispose of depleted Ni-MH cells in full compliance with local environmental regulations.\u003c\/p\u003e","brand":"Yokogawa","offers":[{"title":"Default Title","offer_id":43832098095194,"sku":"HHR-21AHF2A1","price":99.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0710\/5957\/0778\/files\/18._aa26bd06-9571-47b4-b765-05fbe005cc49.jpg?v=1786506508","url":"https:\/\/www.spareoil.com\/products\/yokogawa-s9548fa-hhr-21ahf2a1-2-4v-1900mah-dcs-battery-unit","provider":"SpareOil Automation","version":"1.0","type":"link"}