Age?
how to find out?

 

Some batteries have the year stamped on the terminals, check there.

 

if it's that dirty it probably needs replacing.

 

You may find a sticker with a date if you clean it up. Too, you may have to remove the battery to find it.

Used regularly and kept charged, a good battery can last 10-12 years. If not, even a good battery won't make it to the end of the warranty period.

 

At least it's not corroding.

 

If you make sure the water level stay's full

 

May have to unbolt the hold down and slide the plastic protective cover off to see if there is a date sticker on the side somewhere. Stateside the date code is usually placed on the top sticker where it indicates battery type.

 

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More important would be to know the condition of the battery, than just the age. A battery shop should be able to hook up a machine that will tell the amount of current (CCA) that the battery will give. If it's low, then you may need to get a new one.

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i haven't put water in a car battery, uh, ever!

 

They call them Maintenance Free but their not. The electrolite fluid is about half water & when water gets hot it evaporates. I have "saved " 2 battery's by refilling the cells with Filtered water.

 

If one buys an AGM battery, it is truly maintenance free as there is no liquid electrolite to monitor, and the terminals don't corrode like their lead/acid cousins.

 

the OP is from Ukraine where they might not have the same battery standards as us stateside.
in the US there is usually a sticker to show when it was made, such as '06/21' indicating June 2021, but likely this is not the case in UA.

maybe there is a date code somewhere on the stickers, like 201904 indicating April 2019. dates are stated differently in other parts of the world, usually year first then month then day.
201904 could also mean the 4th week of 2019. it's more apparent if it says 201935 - 35th week of 2019.