NETA 2016

PROTEC

Battery Testing Technologies

Testing of Electrical Power System Components Many of the results that are obtained through electrical testing are

evaluated in terms of change over time. Maybe a good analogy that many of us can relate to is:

Or

How a person ages and if they do so gracefully!

Gradual change over many years of reliable service

Have they fallen down and broken something?

Has there been an event resulting in significant change over a short period of time.

Or

Testing of Electrical Power System Components The same criteria used in the aging analogy can be applied to Power

System Components.

Are the components of our power system changing gradually over time?

Does significant change in test results indicate impending failure?

Lets Focus on Batteries

Standards and Guidelines

• IEEE450-2010 - IEEE Recommended Practice for Maintenance, Testing, and Replacement of Vented Lead-Acid Batteries for Stationary Applications

• IEEE1188-2005 - IEEE Recommended Practice for Maintenance, Testing, and Replacement of Valve-Regulated Lead-Acid (VRLA) Batteries for Stationary Applications

• IEEE1106-2005 - IEEE Recommended Practice for Installation, Maintenance, Testing, and Replacement of Vented Nickel-Cadmium Batteries for Stationary Applications

PRC-005-2 Table 1-4(a) Vented Lead Acid Batteries

PRC-005-2 Table 1-4(b) Valve Regulated Lead Acid Batteries

PRC-005-2 Table 1-4(c) Nickel Cadmium (Ni-Cad) Batteries

Ohmic Testing • Ripple Current – Indication of a Battery Charger’s ability

to rectify and Filter an AC input. Could create unnecessary heating within the battery system. (< 5 amps per 100Ah of Capacity).

• Strap Resistance - IEEE Recommended Practices specify that intercell resistance variations be less than 10% of each other.

• Cell - (Impedance, Admittance, Conductance) – Yields comparative results to: Avg. Ohmic value of jars within the same string Same cell over time. A Baseline Ohmic value.

Analysis of Strap Resistance Test Results (Ohmic)

Intercell Connection Resistance

0

100

200

300

400

500

600

700

0 5 10 15 20 25 30 35 40 45 50 55 60

Cell #

Resis

tan

ce (

mic

roO

hm

s)

Inter-tier Cables

Inter-row Cable

Loose Intercell

Connections

Analysis of Ohmic Test Results for Each Cell in a String.

Percent Deviation from Average

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

-15.0% -10.0% -5.0% 0.0% 5.0% 10.0% 15.0% 20.0%

Depending on battery construction/chemistry, the percentage that one cell varies from the average of the string could indicate a need for further investigation. Other methods of measuring change would be to compare the ohmic test results of a specific cell to itself over time, or to a baseline value.

“A Picture is worth a thousand words”

How much weight is that? And how long can you hold it?

8 hrs. later

Capacity/Load Test

Load (Capacity)Testing What do you want to see in performing a load test?

• If the battery will perform as a whole (Load)

• How the components of a battery perform under load (Monitoring)

Analysis of Capacity Test Results

What is it worth to your customers to know about this kind of problem before their batteries fail in service?

Specific Gravity

• Specific gravity is the ratio of the weight of a solution to the weight of an equal volume of water at a specified temperature.

• Specific gravity is used as an indicator of the state of charge (SOC) of a cell or battery.

Charged Discharged

SGs vary based on Application and Battery Chemistry. This information should be verified in battery specific manufacturer’s specifications.

Locating Battery Ground Faults

Isn’t Always A Simple Task. However, It Can Be Simplified By Using the Right Equipment

• Inject A Traceable Signal Between The Faulted Side of the Battery And Ground.

• Characterize the fault in terms of its Impedance in order to differentiate the fault path from that of other intentional paths (i.e. Surge Suppression Capacitors)

• Traced the path of the signal to the location of the Fault

Booth 215

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