I am not familiar with that brand
However I did make batteries for several year in my immediate post grad years
When I starter battery grid plates were 2mm thick and you could hang your washing on them
When I left they were 0,5mm thick & broke under their own weight if not handled carefully .
When this became a problem for things like off-road vehicles, pleasure craft & motorcycles their grids went up to 0.75mm to 1mm and the alloy was changed because of repeated failures,
However the car batteries remained at 0,5mm because car suspension gave them an easy life.
Mower batteries get a rough life as mowers have no suspension & a crude electrical system.
So unless that is a mower battery , it could just be a case of wrong battery for the job.
If your yard is quite rough and you mow hard then you may need to go to a "motorsport" battery .
These have thicker plates, stronger glue in the paste and fiberglass spacers between plates for added support .
The absolute best battery for a mower is the spiral cell battery Toro used for a while that is still available , but take your big wallet with you.
Check the battery terminals for AC when the engine is running.
Electrically this kills batteries faster than a direct short .
Cranking continiously for over a minute or so can also cause the grid plates to warp on cheaper batteries .