1994-1991 BMW 325e, 325i Battery spec

Battery Group Size:48 or 91
  Size 49/93 may work as well.

An Interstate MTP-91 is a good option.


Factory Spec:

Battery Group Size:48

Dimensions:
  Size: 11.38" L x 6.88" W x 6.88" H

Power Configuration:
  Cell Type: Lead-Acid   Voltage: 12.0  Number of Cells:6

Power Ratings:
  Charge Cycle: -
  Reserve Capacity (RC):110 min.
  Cold Cranking Amps (CCA at 0 deg.F):700
  Item Weight: 41.0 lbs.


Interstate MTP-91

 SPECIFICATIONS
  Pro-rata warranty:85 months
  Weight:   36.60 pounds
  Size: 11.38" L x 6.88" W x 6.88" H
  Cranking Amps:   875
  Cold Cranking Amps: 700
  Voltage:   12
  Termination:  A


Optima Dual Post 800 CCA Battery at Pelican Parts

# Model Specifications:
# Size: 10" L x 6.8" W x 7.8" H
# Minimum Weight: 39 lbs
# Voltage: 12.8V
# Cold Cranking Amps:800
# Reserve Capacity: 104 Min.
# Capacity (C/20 Rate): 55 Ah
# Type Post/Terminal: SAE / BCI automotive and GM style side terminal (3/8-16 UNC - 2B, threaded nut)
# BCI Groups: 34/78