7) mu – Alpha Technologies Cordex Controller Ver.3.1x User Manual

Page 56

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0700015-J0 Rev B

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Temp Comp Slope

Desired temperature compensation slope

Number of Cells

Number of battery cells per string

Figure 56 — Battery Properties and Peukert Calculator windows

Open Circuit Voltage

Sets the open circuit voltage (derived from battery manufacturer’s

specifications).

Peukert Number

The Peukert number relates to the internal resistance of a battery and provides

an indication (inversely) of the expected capacity; that is, a lower number is

better.
This number can be entered in two ways. If the battery manufacturer has

supplied a Peukert number, then it can be entered as a simple, one step

numeric entry.
If a Peukert number is not available, it must be calculated. This multi-step

process involves entering four numbers derived from battery manufacturer’s

specifications. Resulting Peukert number should be above 1.000 and below

2.000.

Peukert Calculator

To calculate the Peukert number the Supervisor must enter unique values for

Peukert Time 1 and Peukert Time 2 and the corresponding discharge current

for each. This information is taken from the battery specification sheet. Typically,

time values of two hours and twenty hours provide the necessary data for the

Peukert number calculation.

6.5.7 Battery Properties

The Battery Properties window contains information provided by the

battery manufacturer. This data is used by the Charge Current Con-

trol, Battery Monitor, and Temperature Compensation features.

Capacity Rating (20-
Hour Rate)

Specified total capacity of the battery

string (derived from battery manufacturer’s

specifications and should correspond to

the C/20 Capacity if possible). This value is

used in the calculations for charge current

control function and capacity estimation.
NOTE: If multiple strings are used, this

value represents the total combined

capacity of all battery strings summed

together.

Capacity Calibration

A value that effectively “calibrates” the

Battery Capacity. This is necessary when

the batteries are first commissioned and

whenever an independent test is done to

measure the battery’s capacity.

Figure 57 — Battery Properties - Web

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