Schneider DBK 021 | AEG Modicon PLC Memory Backup Battery

The DBK 021 provides backup power for Modicon PLC memory modules. This lithium battery preserves user programs and retained data during main power loss. It connects directly to compatible CPU or memory cards in the rack. Consequently, your control logic remains safe even during extended outages.

You can install this battery as a replacement for exhausted original units. The DBK 021 fits AEG Modicon models including the 140 CPU series. It also supports various older Modicon 800 and 400 series processors. Therefore, this battery serves many legacy automation systems effectively.

Battery Chemistry and Energy Storage

The unit uses stable lithium-thionyl chloride chemistry for long life. The DBK 021 delivers 3.6 volts nominal output for consistent operation. It stores 2.6 ampere-hours of total energy capacity. This storage supports memory retention for several years under normal conditions.

The battery includes built-in reverse polarity protection for safety. The DBK 021 also features a flame-retardant casing for fire resistance. It contains no hazardous heavy metals like mercury or cadmium. Below is a complete breakdown of its technical characteristics.

Specification	Detail
Product Type	Memory Backup Battery
Battery Chemistry	Lithium-Thionyl Chloride (LiSOCl₂)
Nominal Voltage	3.6V DC
Capacity	2.6 Ah (2600 mAh)
Continuous Current	100 mA (Maximum)
Operating Temperature	-40°C to +85°C
Connector Type	2-pin Molex (Standard)
Dimensions (L x Dia)	50 mm x 33 mm (Approx.)
Weight	0.05 kg (50 grams)
Shelf Life	10 years (Unused)

Connector Interface and Installation

The battery features a pre-attached 2-pin Molex connector. The DBK 021 plugs directly into the battery port on the PLC module. A polarity key on the housing prevents incorrect insertion. The connector locks securely to withstand vibration in industrial environments.

You should replace this battery every five to seven years for reliability. The DBK 021 requires no soldering or special tools for installation. Simply disconnect the old battery and plug in the new one. Therefore, maintenance teams can perform replacements in under two minutes.

Operational Benefits for Legacy Systems

This battery keeps critical data safe during power supply maintenance. The DBK 021 prevents program loss when you disconnect main power. It also maintains real-time clock values and retentive counters reliably. Engineers value this insurance against costly reprogramming efforts.