Battery Sizing Calculator

Size battery banks for backup power per IEEE 485/1115.

%
Typical: 1.25
% (typical 10-20%)
Per cell minimum

Temperature Capacity Factors

Temperature Lead-Acid NiCd Li-Ion
77°F (25°C)100%100%100%
60°F (16°C)92%95%98%
40°F (4°C)82%90%95%
32°F (0°C)75%85%90%
0°F (-18°C)55%70%75%

Battery Type Characteristics

Type Cycles Typical DOD
VRLA AGM200-40050-80%
VRLA Gel400-60050-80%
Flooded500-150050-80%
NiCd1500-200080-100%
Li-Ion2000-500080-90%

IEEE Battery Sizing Standards

IEEE 485 (Lead-Acid)

  • Size for duty cycle profile
  • Account for end-of-life capacity
  • Temperature correction required
  • Design margin: 10-25%

IEEE 1115 (NiCd)

  • Higher discharge rate capability
  • Better low-temp performance
  • Longer cycle life
  • Memory effect considerations