IMO the Canadian tire batteries are crap period ,agm, conventional, gel does not seam to matter they all crap out quick from y experience,i stay away from there batteries.
There are very few battery manufacturers - and they make branded batteries for 100's - if not 1000s of different companies.
Last info I have for CT batteries listed below.
Deep cycle (Nautilus) batteries are from Exide Battery
Eliminator batteries are from Canadian Energy batteries.
Car batteries are from Deka batteries.
AGM batteries are from Northstar battery.
Costco (Kirkland) deep cycle are from Interstate Batteries. Cannot immediately recall who supplies the AGM, but I think I posted that info here quite some time ago.
Walmart deep cycles, at one time were from Johnson Controls, but they switched suppliers to either Deka or East Penn?
I could make this a 10,000 word post on batteries. But to really summarize: When it comes to buying batteries, a battery from one retailer may be same from another retailer - but with a different sticker / name on it. If you know the battery industry, it is oft-times, amusing to read through the internet where so many will slam one retailers battery, then claim that they then purchased a new battery from another retailer - and it is the same battery.
For what its worth, I have a CT 12 volt Nautilus battery along with 2 Costco 12 volt (Kirkland) deep cycle batteries and years later, no issues with either. My truck is going to need a new battery before next winter and the only difference for me in buying from CT or Costco, comes down to price at the time.