Digital battery tester for your car

About 2 weeks ago, my car's battery was drained to near-empty because I absent-mindedly left the headlamps on overnight. 

While it was fortunate that my motor insurer was able to send a technician over to my place FOC and jump-start my car, the car-hypochondriac inside of me relentlessly nagged me that the incident may have worn my 2 year 0ld battery significantly. My subsequent 30 minute drive to recharge the battery could also have overloaded the alternator.

Tired of worrying, I ordered this car battery tester from Lazada. I figured that between my cars, my family's and my in-law's cars, this could also be handy if we want to check the batteries periodically.

After a few days, the product arrived at my doorstep.

Not seen in the picture above, the package also included the user manual, a USB cable to download and print the test report and a free USB LED lamp.

On with the test - Just clamp the red cable to the positive terminal and the black one to the negative terminal of the car battery. The device is powered by the car's battery so it doesn't need it's own power supply - it should turn on immediately after your connect the terminals; if the device fails to turn on, chances are that your car battery is quite dead.

First test is the battery health test, ran without the engine running. Bear in mind again, this is a 2 year old battery.

For the laymen, the figure to pay attention to is SOH or State-of-Health, which is stated here to be at 63%. The device summarizes the test at the bottom of the screen reporting that it is still a "GOOD BATTERY". I'm not sure at which point it will become a "BAD BATTERY", but at 63% it is fair to say I'll need to keep a close eye on it from here on out.

SOC is the State-of-Charge, which is how much charge the battery is holding. CCA or Cold-Crank-Ampere is used to measure the battery ability to deliver electricity current at a cold temperature. This figure is compared to the battery's original CCA, in this case my battery is originally rated at 545A, but is only delivering 435A in it's current state. 12.59V is the battery's loaded voltage and R is the battery's internal resistance. All the readings are within acceptable range. 

Next up is the cranking test, which tests the car's engine startup system. To test this I simply need to start the car with all the electronic accesories (Aircon, lights, radio, anything connected to the 12V port) switched off.

The reading are pretty self-explanatory - the car took 862 milliseconds to start, drawing power from the battery at 10.42 volts. So far so normal.

The last test is the charging test, which tests the charging circuit and the alternator. This test needs the engine to be running at 2,500 RPM or higher, so once I started the test I need to rev the engine up by stepping on the gas pedal and make sure it stays above 2,500 RPM for at least 5 seconds.

As with the tests before, everything is within normal range, with the alternator delivering power at above 14 volts both loaded and unloaded. The ripple test, which determines if the alternator's internal AC->DC components are healthy, is also within normal range.

So the verdict is everything is within normal operating condition, but I'll need to pay close attention to the battery's deterioration for the next couple of months. I have also compared the readings with another tester at a workshop near my place and everything seem to tally closely.

A small disclaimer though : The tester is not 100% indicative of your battery's life. One of my friends had his battery checked at the service center which yielded a healthy report, only to have it die the very next day. Although I believe this is an isolated case as I have had my car battery tested countless times with no issues, just bear in mind there is still an element of luck involved, and it is a good practice to always keep handy the contact details for your motor insurer's roadside assist. In a pinch, there are also several battery sellers in Malaysia that can deliver a new battery to your location and install it too, for example Carput and Bateriku.

If you are concerned with the health of your car's battery or charging system, this device is a very convenient tool to keep in your home. It costs me around RM95 ($22 USD) so it is relatively cheap for something you can use for a long time, especially if you have a few cars at home. Testing is also very easy even for non-car people, and takes just a few minutes.