As already mentioned you should name the battery and store bought from. Aliexpress is simply a market place like Ebay
As I already said I will name the store once I have no more doubt he knows about it and I've got all the supporting "evidence" done (pictures, videos). You can go to Aliexpress, put in "lifepo4 battery 24v 100ah" select shipping under 15 days to any EU country and you'll see all these stores with no internal resistance numbers or very high internal resistance numbers.
Litokalla is not amongst them. All their stuff is shipping from China now.
However, I wonder, can one call the stores that openly say they sell 200mOhm batteries scammers? I think they prey on people not noticing it, but it is a completely different, much lesser grade of scam than selling 50ah battery as 100ah. This guy has sent me the spec sheet for the battery where it says internal resistance is up to half an ohm (500mOhm) and I stupidly assumed it is a mistake (the battery was already on its way to me at the time, but I could've declined delivery).
Stores that don't give you this spec and then do the same is another matter.
I do agree that the majority of lowest cost batteries you will find are not great for meeting ratings. However one should do a cost analysis between what you pay and get from all items. Cheap lead acid batteries are just as likely to disappoint as cheap Li. In some case I found them much worse in terms of price per ah and longevity.
I've been very happy with my very cheap cell purchases. Also with lots of other "cheap" things including my cheap lead acid, a lot of my electronic equipment and tools etc. Cheap doesn't have to be bad at all. It often is, but not always.
I have been pleased so far with my dead cheap Littokalas (oldest one is 1.5 years now) shipped from China from a recognized store (not one of those that is just numbers). They have out performed similar rated low cost deep cycle lead acid. But I had low expectations and never worried about internal resistance measurements.
I have only head good things about Litokalla. So the below is in general.
With batteries, you may say "you don't worry about internal resistance measurements" and whether it will really matter to you or not depends on the type of load you plan on using. If all you want to power is a 100W terrarium heater so your lizzard doesn't get cold during a power outage you'll not notice any problems even at 200mOhm (24V). But try running a 1kW device and instead of slightly derating the capacity because you're doing a 0.5C discharge while the cell was rated at 0.2C you get 20% of the capacity because there is 3V of voltage drop so your inverter cuts off with 70% of juice left in the cell.
That's why horrible internal resistance numbers matter. It is not an abstract number to put on a sticker. It is a measure of what current you can get out of your cell while it is being discharged.
Also, on the subject of my battery. I've completed a full 6A discharge to 21V. It measured 71AH or 1828wH. This is significantly less than 0.2C it is supposed to be rated at.
After it cut off, the battery recovered to 22.5V. If the internal resistance was good I'm pretty sure it'd be 100ah.
Here's during the test. You can see 200mOhm measurements. Cables add 57mOhm to it so the battery is really about 150mOhm
Oh and before anyone says you measure internal resistance at full charge, lifepo batteries have pretty flat internal resistance during discharge. It is slightly higher at the very top and bottom.