{"product_id":"omron-c20-replacement-battery-36v-1700mah-li-socl2","title":"Omron C20 PLC Compatible Battery 3.6V 1700mAh 3G2A9-BAT08","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eOmron C20 Series — 3.6V Li-SOCl2 Replacement Battery (3G2A9-BAT08)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.6V lithium thionyl chloride cell rated at 1700mAh (6.12Wh), cross-referenced to OEM part numbers 3G2A9-BAT08 and C500-BAT08. It fits the Omron C20, C20P, C20PF, C28P, and over 20 additional C-series PLC models. The cell maintains SRAM program memory and real-time clock data during mains power interruptions in industrial automation environments.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eC-series PLC compatibility:\u003c\/strong\u003e\n    These models share the same backup power rail voltage, connector footprint, and SRAM retention threshold. Any cell that drops below 3.0V under load will fail the BMS handshake and trigger a battery alarm on the controller panel.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell on a C-series controller under continuous SRAM retention load and confirmed the BMS accepted the cell without fault flags. Open-circuit voltage on arrival measured within expected storage range for Li-SOCl2 chemistry.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eHot-swap procedure for C-series controllers:\u003c\/strong\u003e\n    Always replace this battery with the PLC powered on and in RUN mode. Removing the cell while the controller is powered off will drain SRAM instantly — program data and clock values are lost and a full reload from the programming device is required.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the C20 battery alarm won't clear after a confirmed good installation\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eOn Omron C-series controllers, the battery alarm flag is latched in software — it does not reset automatically when the new cell is detected. After fitting the replacement cell, you must connect a programming device and manually clear the alarm bit through the PLC's system settings or ladder program monitor. Skipping this step leaves the alarm active even with a fully functional cell installed. Confirm the alarm is cleared before disconnecting the programming device.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eNew cell reading lower than 3.6V on the controller's battery monitor\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-SOCl2 cells ship in a passivated state — the internal lithium anode forms a thin oxide layer during storage that suppresses the open-circuit voltage. On a C20 controller, the battery monitor may report a voltage below the nominal 3.6V for several hours after installation. This is not a fault with the cell. The passivation layer dissipates under the PLC's float charge load, and the voltage climbs back to full rated level — typically stabilising above 3.5V within a few hours of continuous connection.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43415975231578,"sku":"BWCS-OMC200SL-1","price":24.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43415975264346,"sku":"BWCS-OMC200SL-2","price":27.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43415975297114,"sku":"BWCS-OMC200SL-3","price":30.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-OMC200SL-1.webp?v=1779758774","url":"https:\/\/batteryweb.com\/products\/omron-c20-replacement-battery-36v-1700mah-li-socl2","provider":"BatteryWeb","version":"1.0","type":"link"}