Found that a few years back when we were changing from the old wet lead acid to something "better" , in my case Odyssey batteries which were half the size and four times the price of the big 30 AH wet battery in my BMWs.
First one just died under load one month short of the 12 month replacement warranty, second made it one month past.
No warning, still full resting volts, but just died under load.
I understand this is how most new tech batteries fail, they don't grow old gracefully like the old wet ones.
Compact and low cost load testers are now available for home use , I have a Topdon which was less than $25- it it gives you a good warning of potential problems which a simple voltage reading will not,
A test is now part of my normal service procedure, and I also like to fit a warning light like the GAMMATRONIX unit which gives a good warning of developing problems too..
Still waiting on my new ignition switch, have back fed the live side of the switch with a fused and switched lead and it has actually improved starting.
It usually started first go, but sometimes after a crank or two, but it now bursts into life instantly, must have had a voltage loss through the old switch.