CSB MSJ400 2V 439Ah VRLA Battery Cell, Flame-Retardant Case

What is the CSB MSJ400?

The CSB MSJ400 is a 2 V, 439 Ah valve-regulated lead-acid (VRLA) battery with absorbent glass mat (AGM) construction from the CSB MSJ series (2 V High Capacity). It is sealed and maintenance-free: it never needs water.

CSB designs this series for high-capacity float service standby power. This part number has a flame-retardant (UL 94-V0) case as standard.

What are the specifications of the CSB MSJ400?

Figures published by CSB in the MSJ-400 datasheet (2026 edition), with the CSB price list attributes marked:

Nominal voltage: 2 V
Nominal capacity (CSB price list): 439 Ah
Rated capacity, 20-hour rate to 1.75 V/cell, 25 °C: 420 Ah
Rated capacity, 8-hour rate to 1.75 V/cell, 25 °C: 405.6 Ah
Maximum charge current: 120 A
Maximum discharge current: 2400 A
Internal resistance: approx. 0.3 mΩ
Terminal: I4 threaded insert for M8 bolt
Container: flame-retardant ABS, UL 94-V0
Flame-retardant case: standard on this part number (CSB price list)
Weight, approx.: 63.03 lb (28.6 kg)
Dimensions (W x D x H): 170 x 197 x 339 mm (6.69 x 7.76 x 13.15 in)
Design life: up to 20 years in standby service at 25 °C; Eurobat (20 °C) classification: >12 years, very long life
Discharge temperature range: -15 to 50 °C
Float charging voltage: 2.21 – 2.25 V per cell at 25 °C (77 °F)
Equalize / cycle charging voltage: 2.35 V per cell at 25 °C (77 °F)
Standards (CSB datasheet): IEC 60896-21/22:2004, UL1973 Listed (MH66728) and UL1989 Recognized (MH14533)

How do I request a quote for the CSB MSJ400?

Request a quote by the part number MSJ400. Tell us the quantity you need and, where CSB lists more than one terminal or case option, which one. We confirm price, availability and lead time with the quote.