Battery Tester

I'm not having any progress interpreting the result and the instructions do not say what the terms mean. Any help, greatly appreciated! I'll note that I drove the 4Runner last night and test was today around 1:00pm. Few months ago I left lights on and drained it enough to only try to turn over a little, once. Needed to jump and since then has sounded weak..hard to tell.
I think it's time for a new one maybe? This is the original Panasonic that came with 4Runner from Japan. 2018 Model.

 

That battery tester injects AC voltage waveforms into the battery, takes some voltage readings, then calculates Cold Cranking Amps and the internal battery impedance. If it calculated 386 Amps and the battery is rated at 530 Amps then 386/530=0.73, a 73% State of Health, which is good. The 7.77 milliohm internal impedance is pretty low which is good.

The open circuit voltage (12.22v) is low. It’s state-of-charge is only at 36% of the optimum of 12.65v (100% charged). This doesn’t necessarily mean the battery is bad, all batteries slowly deteriorate over time. Try charging it with a good quality charger and test it again. In fact, that’s what the device is reporting: the battery is GOOD but needs to be RECHARGEd.
(Maybe get a battery charger/maintainer like a NOCO Genius).

 

Thank you for reply! I turned off the DC breaker going to my 2nd batt to do this test, so it should have only been measuring the primary starter batt. Engine was turned off. Since I drove the night before should the state-of-charge be higher?
Which NOCO Genius model would you recommend? I have an old Sears metal box batt charger somewhere but I bet it's close to 40 years old, so not going to trust it.

 

Haha! I think I had that same Sears charger. Just a big heavy transformer and rectifier.

If you’re not daily driving several hours a day you should top off the battery often. Especially with cold weather and an older battery. The OEM Panasonics have a good reputation for long life with proper care.

I use the NOCO Genius5.
NOCO GENIUS5, 5-Amp Fully-Automatic Smart Charger, 6V and 12V Portable Battery Charger, Battery Maintainer, Trickle Charger, and Battery Desulfator with Temperature Compensation

$70 NOCO GENIUS5, 5A Smart Car Battery Charger, 6V and 12V Automotive Charger, Battery Maintainer, Trickle Charger, Float Charger and Desulfator for Motorcycle, ATV, Lithium and Deep Cycle Batteries

https://www.amazon.com/dp/B07W8KJH44?_encoding=UTF8

 

If you don't have a good quality car battery Auto batteries tester, you'll never really have an accurate idea of what condition your battery is in and how much of a charge it's really capable of retaining.

 

What’s wrong with the Sears battery charger. That’s what I still use I can read a battery by the needle gauge?

 

A lead acid battery and a good old sears charger are fine. New cars may have newer types of batteries, but an old fashioned built when it mattered charger is great.
Now we have many electronics that have special batteries, not sure of cars, and they need better chargers. Hence a home generator, needs good electronics to charge cell phones and the like..
The car charging mechanism, an alternator, is pretty good considering what it has to do while driving. Simple motor, regulator set up..

 

I use an old school carbon pile load tester to determine if my battery is due for a replacement. I first ensure battery voltage is at 12(+) volts then apply a load (depending on battery specs) usually around 200 amps for 15 seconds - if voltage maintains 10.5+ under load I consider it a good battery. If voltage can't maintain 10.5 volts and continues to drop I discard & replace. May not be the most scientific method but has worked for me for (too) many years..