Battery Testing

There are number of tests that can be performed to check the condition of the battery. Today I am going to check my battery EXIDE X56C with 550 CCA. It is maintenance free type of the batteries.

First is visual test.
 Check the battery for leaks, cracks, and signs of swelling, check that terminals are clean. Check that electrolyte in all cells is at recommended level (if not, add distil water)

OCV test 
Open Circuit Voltage requires voltmeter. Get voltage readings from the battery terminals (doors should be closed, IGN key is out and all interior/exterior lights should be turned off).  Surface Charge must be removed by turning on headlights for about one minute.

Readings:

12.6 V – 12.7 V = 100% of Charge

12.45 V – 12.5 V = 75% of Charge

12.3 V – 12.4 V = 50 % of Charge

12.15 V – 12.2 V = 25 % of Charge

the Voltage is 12.77V. PASS

If Voltage is less than 12.3 V then Battery should be charged overnight. 13.8 V-14.9 V power supply can be used with current of 2A-8A to charge the battery (lower Current and longer charging time is better). Connect “+” on power supply with “+” battery and “-“  power supply with “-“ battery terminal.

Hydrometer Test.
 Hydrometer, Safety Glasses and source of water nearby are required. Open cell caps in all cells. Place hydrometer in the cell and squeeze the rubber top on hydrometer. Let some electrolyte in (not too much, just enough to make the tube inside hydrometer to float).  Eye level should be in height with fluid inside the hydrometer in order to get correct readings.

1.240 – 1.260 = 100% Charged

1.210 – 1.240 = 75% Charged

1.180 – 1.210 = 50 % Charged

 1.150 – 1.180 = 25 % Charged

In my case battery is sealed. unable to perform this Test.

High rate discharge test

for this test we need load tester. we would need to apply a half of battery's CCA (550/2=275A) for 15-20 seconds. During this test battery's voltage should not drop below 9.6 Volts. connect load tester cables to battery's terminals, positive to positive and negative to negative. Rotate the knob on load tester until you reach 275 Amps. Keep an eye on build in Volt Meter (or you can use separate one) the voltage should not go below 9.6V mark during 15-20 seconds. voltage reading: 10.2V. PASS 

alternatively, car's starter can be used instead of load tester. make sure you disconnect the IGN coil (to prevent car from starting). connect your voltmeter to the battery and get someone to crank the engine while you taking Voltage readings.


Amp Draw


This test determines how much current drains from the battery when the car is off, all doors are closed and IGN key is out. For this test we need working Amp meter. DO NOT START THE CAR as you can damage your Amp meter (if it's unfused). Make sure you connect Amp meter in series with battery (so the current will flow through the Amp meter). Connect Battery Negative to Amp meter Negative and car's negative terminal to Amp meter positive. Accepted range is 0.03-0.05 Amps. 

it's 0.025 A. PASS

Digital Battery Test

This is the most common test that used by battery dealers nowadays. since the tester powered by the Battery being tested, make sure the voltage of the battery is not below 7 Volts. connect tester to battery's terminals, positive to positive and negative to negative. Once connected, the tester should display the voltage of the battery. using "arrow up" and "arrow down" buttons choose the right CCA for your battery, in my case it's 550 CCA. once selected correct CCA press "test" button. The Tester might show the following "CH"- charge the battery to continue the test, "PASS" - no faults found and battery is in good order, "FAIL" - fault was detected during the test.

I got "PASS".

Battery Report:

The Battery has passed all tests and it is in good condition and does not require any further testing/maintenance. Battery is ready to use.