Scotty and Moderators,
I'm looking at buying myself a battery tester to test my battery on my car. I have a 2019 corolla with currently 73,000 miles 1.8L. The battery is still the original one, but its obviously 4 years old and will most likely need replacing soon. I took it to the auto zone in my area 2 months ago and they said the battery fine, and the only thing they said is that the charge was 100% and that the reserve capacity is OK. My mechanic at the garage I mainly go to tested it and they have a very similar to tester that auto zone has with the charge and stuff, and they don't have a tester that shows the value/life percentage of the battery (so I have a lot better idea as to when I need to change it). I'm pretty sure Scotty did a video a few months ago on a good battery tester that you can buy. Not sure if I can find that video now. But let me know a good one (that's not too expensive) that I can buy for myself to test my battery that actually shows the life percentage (or value) left of my battery, not just the charge and reserve capacity. Thanks.
I don't buy battery testers because the good ones are very expensive, and I rarely need them. When I do, I go to my battery dealers and let them use their heavy duty carbon pile tester for free, and get my battery right there if needed.
they don't have a tester that shows the value/life percentage of the battery
there's no such thing. There is no tester that looks inside the battery to asses the physical condition. Any tester that claims to know the "life expectancy" is lying. All it can measure is the output.
so I have a lot better idea as to when I need to change it
when you have trouble starting in the morning, change it.
Scotty has used a number of different battery testers in his videos. Some time ago he recommended an "Autool" BT-460 which isn't too expensive. I've found it works well for the price, but I also use an old-school resistance-type unit for load testing.
https://www.amazon.com/BT-460-Lead-Acid-Colorful-Analyzer-Vehicles/dp/B00ZRAFH5G
https://www.amazon.com/Neiko-40510A-Volt-Battery-Tester/dp/B07B3R4TS6
Does these battery testers that you shared (including the Autool" BT-460) show the life/value of the battery? Or just the charge and reserve capacity that it's giving?
It does show percentage of remaining life but bear in mind it's just estimated from the internal resistance of the battery. A tester that can really do in-depth analysis of a car battery would be a lot more expensive, probably not cost-effective for anyone but a professional mechanic.