Environmental Engineering Reference
In-Depth Information
discharge performance and Word 2 are charge acceptance and life effects. The
constituents of Word 1 and Word 2 are defined here:
Word 1
1.
Capacity point
The battery's ability to deliver charge at the
C
/2 rate; also sets a data point for Peukert's curve;
closely tied to reserve capacity
2.
Peukert's slope
Describes the battery's ability to deliver charge at
different rates
3.
Charged voltage
Open circuit voltage of a battery at equilibrium when
fully charged and at rest with no loads applied
4.
OCV/SOC slope
Slope of the curve that describes open circuit voltage
versus SOC
5.
Initial IR
Total ohmic resistance of a new battery that has been
charged and conditioned; measured in m
W
6.
Ionic/Elect
Ratio of ionic resistive component to the electronic
resistive component in the battery; a model of the
temperature dependence of the battery
7.
Kinetics
Describes the voltage drop due to the reaction to form
lead sulphate; a typically non-linear voltage drop plus
temperature corrected internal resistance that gives
the battery voltage drop under load
8.
Thermal time
Time constant of the battery in regard to heat dissipation;
defined as heat capacity divided by heat transfer
coefficient
Word 2
9.
At 40
C; test determines the time to charge from 80%
to 95% capacity at 40
C and 14.0 V
Charge
acceptance
At 0
C; test determines the time to charge from 80%
to 95% capacity at 0
C and 14.7 V
10.
Charge
acceptance
Current; measure of the charge acceptance at 40
Cat
1 min into test
11.
Charge
acceptance
12.
Shallow cycle
life
Number of cycles to 50% capacity at the 2 h rate of
discharge, tested at 40
C when charged to 80% of
capacity
13.
Overcharge
Resistance; number of days of overcharge to add 50% to
the battery
I
IR; tested at 50
C and 0.1 V/cell above
measured
I
IR at 25
C
Test to determine the water loss in ml/h at 50
C and
0.3 V/cell above the charged voltage
14.
Gassing
15.
Overcharge CA
Current measured on #14; current is measured during
gas collection in battery
16.
Condition factors
Factor used in determining the battery's reaction to
self-discharge on charge acceptance and its available
volume; made up of two factors: battery type and
acid availability
Validation of the available energy battery model has been performed by
Johnson Controls and described in terms of a 'water tower' model. In this model, a
representative plate within the battery is shown to lose charge from both sides
