{"product_id":"ds-miller-b220-replacement-battery-36v-2700mah-li-mno2","title":"DS Miller B220 PLC Replacement Battery 3.6V 2700mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eDS Miller B220 — 3.6V Li-MnO2 Replacement Battery\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3.6V, 2700mAh lithium manganese dioxide cell replaces the backup battery in the DS Miller B220 PLC. It maintains SRAM program memory and real-time clock function when mains power is interrupted or the controller is powered down. Without a live cell, the B220 loses its stored program and clock data.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eB220 PLC memory retention:\u003c\/strong\u003e\n    The B220 uses this cell solely to hold SRAM state and RTC values during power loss. The 3.6V nominal voltage matches the retention rail the controller expects. A depleted or missing cell means the PLC boots with no program loaded and an invalid clock.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We confirmed stable open-circuit voltage and verified the cell holds the retention threshold under a simulated SRAM load across the full specified capacity. The Li-MnO2 chemistry delivers a flat discharge curve, which keeps the memory rail above the PLC's low-battery trip point for the majority of the cell's service life.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eHot-swap procedure for the B220:\u003c\/strong\u003e\n    Always replace this battery with the PLC powered on and in RUN mode. Removing the cell while the controller is off — even briefly — will erase SRAM contents. If the swap was done with the unit off, a full program reload from the programming device is required before the B220 can resume normal operation.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the B220 loses its program after a battery swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe B220 holds its ladder logic and configuration in SRAM, not flash. SRAM is volatile — it needs a continuous voltage supply to retain data. The backup cell is the only power source for that memory when mains is absent. The moment the cell is disconnected with the controller off, the SRAM loses power and all stored data is gone within seconds.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eBattery alarm not clearing after fitting a new cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA fresh cell does not automatically reset the low-battery alarm in most PLC firmware. The controller latches the fault flag when voltage drops below threshold, and it stays latched until cleared manually. Connect to the B220 via the programming software, navigate to the diagnostics or status register, and clear the battery fault flag explicitly. After the clear, confirm the alarm is gone before closing the session — a new cell reading slightly below 3.6V on first install is normal and will rise to rated voltage within a few hours on the controller's float charge.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43415969792090,"sku":"BWCS-PLB386SL-1","price":30.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43415969824858,"sku":"BWCS-PLB386SL-2","price":35.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43415969857626,"sku":"BWCS-PLB386SL-3","price":38.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-PLB386SL-1.webp?v=1779758775","url":"https:\/\/batteryweb.com\/products\/ds-miller-b220-replacement-battery-36v-2700mah-li-mno2","provider":"BatteryWeb","version":"1.0","type":"link"}