Battery OEM Chevrolet or OEM Mazda

We've been driving two EVs, a 2012 Leaf since Dec2011 and a 2017 Bolt since Sept 2017.

In the Bolt we lose about 40% range at -20 and lower. Bu the range is so good to begin with its not an issue.

Battery died less than 12000 miles. Apparently Mazda is using cheap batteries, as this seems to be a common issue. But I still see others complain about the same thing.

first issue I had was the battery at around 2000 miles, it was replaced under warranty.

So far have not had any issues except for dud OEM battery, kriginal and warranty...