How to test an AGM/EFB (enhanced flooded) starter car battery for capacity and current DIY

Device:
Varta Blue Dynamic EFB Battery amzn.to/3zGIetz
Multimeter amzn.to/3PKYBLs
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A valve regulated lead-acid (VRLA) battery, commonly known as a sealed lead-acid (SLA) battery, is a type of lead-acid battery characterized by a limited amount of electrolyte ("starved" electrolyte) absorbed in a plate separator or formed into a gel; proportioning of the negative and positive plates so that oxygen recombination is facilitated within the cell; and the presence of a relief valve that retains the battery contents independent of the position of the cells.
There are two primary types of VRLA batteries, absorbent glass mat (AGM) and gel cell (gel battery). Gel cells add silica dust to the electrolyte, forming a thick putty like gel. AGM (absorbent glass mat) batteries feature fiberglass mesh between the battery plates which serves to contain the electrolyte and separate the plates. Both types of VRLA batteries offer advantages and disadvantages compared to flooded vented lead-acid (VLA) batteries or each other.
Due to their construction, the gel cell and AGM types of VRLA can be mounted in any orientation, and do not require constant maintenance. The term "maintenance free" is a misnomer as VRLA batteries still require cleaning and regular functional testing. They are widely used in large portable electrical devices, off-grid power systems and similar roles, where large amounts of storage are needed at a lower cost than other low maintenance technologies like lithium ion.
Lead-acid cells consist of two plates of lead, which serve as electrodes, suspended in an electrolyte consisting of diluted sulfuric acid. VRLA cells have the same chemistry, except the electrolyte is immobilized. In AGM this is accomplished with a fiberglass mat; in gel batteries or "gel cells", the electrolyte is in the form of a paste like gel created by adding silica and other gelling agents to the electrolyte.
When a cell discharges, the lead and diluted acid undergo a chemical reaction that produces lead sulfate and water. When a cell is subsequently charged, the lead sulfate and water are turned back into lead and acid. In all lead-acid battery designs, charging current must be adjusted to match the ability of the battery to absorb the energy. If the charging current is too great, electrolysis will occur, decomposing water into hydrogen and oxygen, in addition to the intended conversion of lead sulfate and water into lead dioxide, lead, and sulfuric acid (the reverse of the discharge process). If these gases are allowed to escape, as in a conventional flooded cell, the battery will need to have water (or electrolyte) added from time to time. In contrast, VRLA batteries retain generated gases within the battery as long as the pressure remains within safe levels. Under normal operating conditions the gases can then recombine within the battery itself, sometimes with the help of a catalyst, and no additional electrolyte is needed. However, if the pressure exceeds safety limits, safety valves open to allow the excess gases to escape, and in doing so regulate the pressure back to safe levels (hence "valve regulated" in "VRLA").
(Source: Wikipedia)
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[@TheRossMcLean]

This was excellent. Thank you! The only piece of feedback I could give is an ask for you to change the language on your devices to English to match the language spoken in your video. It's not a dealbreaker as I can just screenshot and translate but it would make it much easier to comprehend quickly. Thanks again :)

[@johngroves1023]

At what internal resistance should we be replacing an EFB battery?

[@Mickytdi]

I wonder about the accuracy of these testers. My 5 year and 10 month old battery reads 350 cca (26 % SOH) on a 680cca battery and says “ replace”. The tester has been telling me to replace the battery for over a year. But it started the car no problem at -7 degrees C yesterday.

[@lcpd26]

This is not always related...
Example...
My corolla 1.2turbio requires less than 220 CCA to start as I found out...
Stock battery is 340 CCA, now after 4 years 180 CCA or 220 CCA fully charged..
But car still starts (says replace battery)
However light gets dimmer on crank...
I replaced it with a 640cca 60 ah used efb battery and it starts way better and no dimming lights on crank...
Definatly the efb battery is better than regular

[@lcpd26]

And voltage engine off immediately fell on 12.2 to 12.3 volts
And now voltage falls 12.7 to 12.9 even after some time

[@KutsiTekin]

Agm Batteries are very expensive and can I choose an efb battery that I can maintain or your suggestion?

[@halicisinan3117]

Is it good battery? I don't have so much information about banner efb. I have same battery which is on your test.

[@KutsiTekin]

hello, is efb battery suitable for solar system?