APPLICATION NOTE
7
Table 1 Cell Parameters
Cell Model Parameter Meaning
LEAD-ACID
CAPACITY
Capacity of the battery measured at the 20 hour rate
RESISTANCE Mid-discharge cell resistance in ohms
CELLS
The number of cells that make up the battery(6V = 3
cells, 12V = 6, etc.)
Note: These parameters are only needed at a discharge rate greater than 5C to account for cell temperature rise.
Since little standardization exists for rating methods between manufacturers, the popular typical parameters are
summarized in Table 2 for the most common consumer batteries
Table 2 Subcircuit Parameters for the Cell Models
Cell Type Capacity(Amp-hour) Resistance(Ohms) Volume(in3) Weight(gm) Cell Number
Alkaline Cells
Typical subcircuit call for a single Alkaline N cell:
X1 +node -node SOC RATE ALKALINE PARAMS: CAPACITY=0.9,RESISTANCE=5
N
0.9 0.8
— — —
AAA
1.2 0.6
— — —
AA
2.5 0.3
— — —
C
7.5 0.2
— — —
D
16.4 0.07
— — —
Nickel-Cadmium Cells (Standard)
1
Typical subcircuit call for a single NICD N cell:
X1 +node -node SOC RATE CELL_TEMP NICD PARAMS: CAPACITY=0.15, RESISTANCE=5,
VOLUME=0.2, WT=9
N
0.15 0.027 0.2 9
—
AAA
0.18 0.021 0.24 10
—
AA
0.48 0.012 0.48 24
—
SUBC
1.2 0.005 1.1 50
—
C
2
1.8 0.0045 1.6 80
—
D
2
4.0 0.0035 3.4 160
—
Nickel-Metal-Hydride Cells
Typical subcircuit call for a single NIMH AA cell:
X1 +node -node SOC RATE NIMH PARAMS: CAPACITY=1.1,RESISTANCE=0.03
AA
1.1 0.03
— — —
4/5A
1.5
0.02(estimated) — — —
Lead-Acid Cells
Typical subcircuit call for a 6 Volt, 1.3 Amp-hour Lead-Acid battery:
X1 +node -node SOC RATE LEADACID PARAMS: CAPACITY=1.3,RESISTANCE=0.06,CELLS=3
6V-1.3A-hr
1.3 0.06
— —
3
6V-4.0A-hr
4.0 0.025
— —
3
6V-6.5A-hr
6.5 0.02
— —
3
6V-10A-hr
10 0.015
— —
3
12V-1.3A-hr
1.3 0.12
— —
6
12V-4.0A-hr
4.0 0.05
— —
6
12V-6.5A-hr
6.5 0.04
— —
6
12V-10A-hr
10 0.03
— —
6
