ABB SB822 3BSC760019E1 Memory Retention Battery — SRAM Backup for PM860/PM861/PM864/PM865 CPUs

Product Overview

The ABB 3BSC760019E1​ (ABB type designation SB822, cell code AB12G, manufacturing lot 364-1115) is a rechargeable lithium-ion memory-retention battery engineered as a critical accessory for ABB’s AC 800M and 800xA Distributed Control System (DCS) controller family. Housed inside the external SB822​ battery unit (product ID 3BSE018172R1), the ABB 3BSC760019E1​ performs one job, and performs it silently for years: it maintains the CPU’s volatile SRAM and real-time clock (RTC) when the 24 V DC control power disappears. That single function is the difference between a power interruption that the operator never notices and a “Memory Lost” event that costs a refinery, a paper machine, or a power block hours of production.

With a nominal voltage of 3.7 V DC​ and a rated capacity of 2.4 Ah​ (2400 mAh), the ABB 3BSC760019E1 SB822 AB12G​ is precisely matched to the standby current draw of the PM86x CPU family. In its intended duty cycle, the cell sits in a float-charge state during normal operation — the SB822 unit’s internal charging circuit holding it at approximately 3.75 V — and only discharges during actual outages. This is why its published backup time reaches up to 490 hours​ (roughly 20 days) of RAM retention: the load is measured in milliamperes, not amperes. The ABB 3BSC760019E1​ is therefore not a UPS substitute and must never be specified as one; it protects data, not actuators.

The cell chemistry is rechargeable lithium-ion, chosen by ABB over the NiCd and NiMH alternatives of earlier DCS generations for its low self-discharge, flat discharge curve, and superior energy-to-weight ratio. A fully depleted ABB 3BSC760019E1​ recovers to full charge in approximately 2 to 7 hours​ at room temperature, depending on the charging circuit revision, meaning a single planned maintenance shift restores full backup capability. The cell is rated for a minimum of 500 charge cycles, with 1000 cycles​ typical under shallow-discharge float service, and an expected calendar life of 3 to 5 years​ in a cabinet held below 40°C. The ABB SB822 3BSC760019E1​ is supplied as new-original stock, individually lot-traceable, with the date code and cell code (AB12G, Anit 365-731) legible on the cell wrap — a detail that matters, because a battery that looks identical but carries a 2015 date code is already past its useful life regardless of its open-circuit voltage.

Technical Specifications