A while ago i read in this forum someone stating that the Mazda 3 batteries
are not very good, especially in cold weather.

What do you think. Is it worth buying a better one. What battery do
you recommend. Is it just the battery or the starter too.

I some times come out of a XC ski center late in the day. Last time, there
were only 3 car left in the parking, the park staff had left, closest
neighbor were at at least 10km away and it wad -25c.

 

I got my car in August 2007. My battery always was a lil poopie when it's colder outside, randomly one day the car wouldn't turn over at all. My hero of a dad put the biggest best "cold cranking" battery that would fit in the car in it this season, but the original battery survived Oklahoma cold until now.

 

Wrap some insulation around it. It helped for me. For more please read:
https://www.mazdaforum.com/forum/maz...tteries-27572/

 

My OE battery lasted 6 yrs before I felt I'd better replace it.
I could tell it was getting weak, but overall it served me quite well. I never expected it to last that long, that's for sure.

Are you checking the fluid levels? Because in spite of what they say, a maintenance free battery is NOT maintenance free. They still go through water in the hot weather especially. You need to keep it up or your battery in any car will die prematurely.

 

We get plenty of cold here in New Hampshire; my Mazda3 is heading into its fourth winter with the factory battery showing no signs of ill health.

 

Denver here and no issues. Single digits it does start a little slower but never had an issue.