Can someone explain warranty vs guarantee in simple words before I buy my next?

[ronaldmorgan]

I am buying a battery for my 2019 Nissan Sunny this weekend, and I want to understand one thing properly before I pay. Two shops gave me two different promises. The first one said "one year guarantee," and the second one said "eighteen months warranty," and both of them said it like it was a big deal. I nodded, but honestly I did not know if those are the same thing or if one is better. My brother says they are just two words for the same promise and I am overthinking. My neighbor says a guarantee usually comes from the shop and a warranty from the brand, and that who gives the promise decides how easy the claim will be. A friend at work told me his claim was refused because he could not show the invoice, even though the battery was clearly dead. Another colleague said to read the small print for words like "misuse" and "proof of purchase," because that is where people lose their claim. I read a page on last night to understand the terms, and it explained what each one usually covers, who handles the claim and which papers you should keep, which showed me how little I checked last time. Since then I have been looking for a Premium explanation of the difference between Amaron battery warranty and guarantee, because I want someone to put it in plain words and not in legal language. My questions are easy. If the shop closes or moves, is a brand warranty still useful? Should the date and the period be written on the invoice, or is the stamp enough? Does a longer period always mean a better battery, or is it only a selling point? And is it fair to ask the shop to explain the conditions before I pay? Please share what you do when you buy. Thanks for reading.