In my case, the battery was near end of average life expectancy by age and I know about how long batteries usually last with my driving habits.
Whether or not the shop ever suggests trickle chargers to any customers I don’t know.
What I do know is that they are very good about not upselling or pushing anything. They will note when by age, mileage, or condition that a particular service although not yet needed will need to be addressed at an upcoming interval.
Awhile back I changed the oil at somewhat early miles because it had gone long by time and I had noticed when checking the dipstick that the oil had darkened noticably within a few weeks. When I took the car in for the oil change they noticed the short mileage and questioned if I was aware.
So although I get why several of you suggest the use of trickle chargers and that you suspect the shop happily installs new batteries more than necessary, I have almost 20 years experience that this shop is trustworthy in their business practices.