It is very cold, how do I know if the car battery is good and the car will start?? What is the best car battery test method?

[Don2222]

Hello
Nowadays there are better tools to get and know how to use! The old standby was the 5 year old premium Sears Die Hard. They are still sold by Advanced Auto but the warranty is 3 years. Our Toyota Venza has one with the date code of 01/22/2021 and will not start in this wether with temps down to 15.4 at night and about 20 degrees F in the morning. The doors unlocked, the dashboard lights lit but not enough cranking Amos to start the car! A jump from another car and it did get going very easily. Also this car is not used every day so that can also contribute to this issue.
Now the RAV4 has an Exide Excel battery that is 4 years old and still starts well unless the dome light is left on all night.
Now testing the car alternator is fairly simple. When the car is running just put a multi-meter on the battery and a voltage reading of approximately 14 VDC indicates the 12 volt battery is getting charged with the higher voltage. If the voltage is not higher that the 12 volt battery then the alternator is bad,
So how do we know if the battery itself is good under a load?
There is a very good vehicle battery tester at Batteries Plus & Bulbs for $44.95 that puts a load on the battery and has a simple to read meter result!
Just attach the battery clamps and depress the momentary rocker switch to load the battery and read the results!
The proof is how it really works so here is what I found.
The Exide Excel battery that is 4 years old when the load button was depressed showed 11 volts and just bearly in the yellow weak area on the top scale.
Just to be safe with the start of this big cold spell I replaced it with a premium high performance X2 I asked why this battery is better than the premium Duracell. They said the Duracell uses recycled lead and the X2 uses pure lead and will last longer than 5 years. After installing the X2 I tested it. Sure enough the results on the 800 CCA Cold Cranking Amp scale for this 840 CCA battery are well in the green after the load button was pressed.
Now what will the DieHard with 650 CCA Venza battery test at??
Looks like the Venza battery with the needle way down in the Red needs to be replaced?
Pic 1 - Batteries Plus - New Auto Battery tester
Pic 2 - Basic Instructions for the Tester
Pic 3-5 New Premium High Performance X2 battery from Batteries Plus
Pic 6 - RAV4 Battery Voltage with just the leads attached with new X2 Battery Installed
Pic 7 - RAV4 Battery Voltage with load button depressed with new X2 Battery Installed
Pic 8 - Venza Battery Voltage with just the leads attached on 3 year old Diehard
Pic 9 - Venza Battery Voltage with load button depressed on 3 year old Diehard

 

[johneh]

Don what you did was what mechanics have been doing since the lead acid battery was invented
A Carbin Pile Test. I am 75 and my tester belonged to my Father in law who was also a mechanic
in the 1940s Same machine just a new look LOL

 

[bigealta]

Just get the digital volt readout that goes in the cigarette lighter. Easy to watch the voltage at startup and when driving. They are super inexpensive.

Obviously it won't do a load test, but you will notice changes in normal voltage readings over time if your battery or alternator starts to fade.

 

[weee123]

In the wrench turning business we called those load testers toasters

 

[Don2222]

A lead acid battery carbon pile test with a toaster!! - That is why this meter Smokes the first time you use it! It states that in the instructions! LOL
Good to Know Thank-You

 

[Murray01]

Why would one shop pass a load test on a brand new AGM battery and a second shop fail a load test claiming one cell is dead? Battery was dated Nov 23 so it sat on a shelf for a year. Said battery was not charged before installation.