4841 Battery testing

SAFETY: Safety glasses should be warn at all times and a nearby water supply should be available 


1. Visual Check
Check the battery case for cracks,swelling and leaks (battery need replacing if any of this 3 sign is showing).
Check electrolyte level in all cells that they are at the correct level  add distilled water if needed (using tap water will shorten lifespan of battery and DO NOT over fill).
Check battery terminals for corrosion and residue, clean if needed (wire brush)


2.O.C.V (Open Circuit Voltage) Test
Tools needed: Voltmeter
Then to remove surface charge with the car off turn the light on for 1 min (if surface charge is not remove  results will be incorrect making a weak battery appear good and good battery appear bad.
Black lead of voltmeter to negative(-) of battery and Red lead of voltmeter to positive(+)
make sure everything is turn off....int/boot lights, ignition key out,  door close.
Compare results with table below

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

3.Hydrometer Test
Tools needed: Hydrometer
Unscrew cell cap. Depress the pump fully and insert the hose at the end of the tube into the cell hole, release pump and electrolyte should start flowing into the tube which then should floats the weight. Look at the tube at eye level and this should give you a reading.

1.240 – 1.260 = 100% Charged

1.210 – 1.240 = 75% Charged

1.180 – 1.210 = 50 % Charged
1.150 – 1.180 = 25 % Charged

4.High rate discharge (Load) test

Tools needed: Load tester
Connect load tester positive lead to positive terminal negative lead to negative terminal. Find the cold cranking amp (CCA) for your battery and half it (half 550CCA = 275A). Set the load tester to 275A and leave it for 15-20seconds during the test the battery voltage should not drop below 9.6 volts.
OR
Tools needed: Voltmeter
Unplug EFI fuse, connect volt meter to battery and crank the engine voltage display should not drop below 9volts.

5.Amp Draw Test
Tools needed: Ammeter
With the car off (key out, no lights on, doors close, boot close....), disconnect the battery negative (you might want to hook up a jumper wire first so you dont loose your memory then once ammeter is wired up you can unhook the jumper wire) and hook up the ammeter in series the result should  around 30-50 mA

6.Digital Battery Test

This is what battery dealers use now a days.  make sure the voltage of the battery is not below 7 volts because the tester will be powered by the Battery being tested. Connect tester to battery terminals positive to positive and negative to negative. When connected the tester should display the voltage of the battery. Using up down arrow buttons choose the CCA of your battery eg 550 CCA, then press test button. The digital battery tester might show CH which means battery need charging to continue the test or give you a result of PASS (no faults found and battery is in good order) or FAIL ( Something is wrong with the battery).