PC World spent a lot of time trying to become a cross between Staples and Toys R Us, and now, since moving shop, can be mystified by a wider range of products than before. If I need a complete new box, I will go for a look, but if looking for add-ons, I tend to go to the on line stores like Saverstore and CCL. Prices are very keen, delivery times often amazing.
The only problem I have had with changing a car battery was that the radio forgot its coding immediately, and needed redoing, but that was a Renault from the past century, so there has been plenty of time for the manufacturers to make life more difficult in the name of improving security.