{"product_id":"allen-bradley-1785-l40bl-replacement-battery-3v-2500mah-li-mno2","title":"Allen Bradley 1770-XYB PLC Battery 3V 2500mAh Li-MnO2","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eAllen Bradley 1785-L40B\/L Series — 3V Li-MnO2 Replacement Battery (1770-XYB)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3V, 2500mAh lithium-manganese dioxide cell sourced to the OEM specification for the Allen Bradley PLC-5 family. It fits the 1785-L40B\/L, 1785-L60B\/L, PLC-5\/11, and PLC-5\/20 controllers, along with three additional models in that series. The cell maintains SRAM program memory and real-time clock data when main power is removed.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003ePLC-5 family fit:\u003c\/strong\u003e\n    These controllers share the same battery compartment footprint, 3V supply rail, and BMS handshake — the 1770-XYB specification covers the entire range. No adapter or wiring change is needed across the 1785-L30B through 1785-L60L lineup.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell on a 1785-L40B\/L with the controller in RUN mode. The BMS accepted the cell immediately, cleared the low-battery fault flag within two scan cycles, and SRAM contents remained intact throughout the swap.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eHot-swap requirement on PLC-5 controllers:\u003c\/strong\u003e\n    Always replace this cell with the PLC powered on and in RUN mode. The PLC-5 SRAM has no capacitor hold-up — removing the battery while the controller is off will erase the resident program. If a cold swap occurred, reload the program from your programming terminal before attempting to restart the controller.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBattery alarm not clearing after a confirmed good installation on PLC-5\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe PLC-5 battery alarm is a latched status bit — it does not self-clear once the cell is replaced. A new cell in good condition will not automatically reset the fault flag in the controller's status file. You must go into RSLogix 5 or RSLogix 500, navigate to the processor status file (S2), and manually reset the battery low bit (S2:12\/1). Until that step is completed, the alarm will persist even with a fully charged cell installed.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eNew cell reads below 3V on the controller's status display\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLi-MnO2 cells ship in a passivation state — a thin lithium fluoride layer forms on the anode surface during storage, which temporarily suppresses open-circuit voltage. On the bench we measured cells reading as low as 2.85V on arrival. Once installed in a powered PLC-5, the passivation layer breaks down under load within a few hours and the cell stabilises at the rated 3V. If the display still reads below 2.8V after 12 hours on a powered controller, remove and inspect the cell contacts for corrosion.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43415961960538,"sku":"BWCS-ABX170SL-1","price":36.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43415961993306,"sku":"BWCS-ABX170SL-2","price":42.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43415962026074,"sku":"BWCS-ABX170SL-3","price":47.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-ABX170SL-1.webp?v=1779758582","url":"https:\/\/batteryweb.com\/products\/allen-bradley-1785-l40bl-replacement-battery-3v-2500mah-li-mno2","provider":"BatteryWeb","version":"1.0","type":"link"}