{"product_id":"omron-c20-replacement-battery-36v-2700mah-li-mno2","title":"Omron C20 PLC Replacement Battery 3.6V 2700mAh 3G2A9-BAT08","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eOmron C20 \/ C20P Series PLC — 3.6V Li-MnO2 Replacement Battery (3G2A9-BAT08)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3.6V lithium manganese dioxide cell replaces the backup battery in Omron C20, C20P, C20PF, C28P, and compatible series PLCs. It supplies 2700mAh of standby power to keep SRAM program memory and the real-time clock alive when main power drops. The OEM part numbers covered are 3G2A9-BAT08 and C500-BAT08.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eC20 and C20P series compatibility:\u003c\/strong\u003e\n    These controllers share the same battery bay, connector pinout, and 3.6V SRAM retention rail. The BMS handshake is passive — voltage threshold only, no authentication — so a direct cell swap is all that's needed provided the dimensions match the 51.20 × 18.90 × 17.10mm footprint.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell against the C20's SRAM retention circuit and confirmed stable voltage delivery at the low-current draw typical of PLC memory backup. The cell held above the 3.0V SRAM dropout threshold throughout the test window.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eHot-swap protocol — critical for C20 series:\u003c\/strong\u003e\n    Always replace this battery with the PLC powered on and in RUN mode. If the controller is powered off during the swap, SRAM loses its retention voltage immediately and the program is wiped. A full reload from the programming device is then required before the machine can return to service.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003ePLC battery alarm not clearing after a confirmed good installation\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eOn C20 series controllers, the battery alarm flag is latched in software — fitting a new cell does not automatically clear it. The alarm must be reset manually through the programming software or the handheld programmer once the new cell is seated and the PLC is in RUN mode. If the flag stays set, check that the cell contacts are making clean contact and the connector is fully engaged. After a confirmed reset, the BAT LED should extinguish within one scan cycle.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eNew cell reading below 3.6V immediately after installation\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-MnO2 cells ship at a storage voltage that can sit noticeably below their rated open-circuit voltage. This is normal — the cell is not defective. Once seated in the PLC, the float charge from the controller's backup circuit brings the measured voltage up over several hours. If the cell still reads below 3.4V after 12 hours on a powered controller, check for excessive voltage drop across the connector pins before replacing the cell.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43415979327578,"sku":"BWCS-PLC276SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43415979360346,"sku":"BWCS-PLC276SL-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43415979393114,"sku":"BWCS-PLC276SL-3","price":28.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-PLC276SL-1.webp?v=1779758818","url":"https:\/\/batteryweb.com\/products\/omron-c20-replacement-battery-36v-2700mah-li-mno2","provider":"BatteryWeb","version":"1.0","type":"link"}