my car wouldnt start today. i recently reset the ecu. could that be the reason? or is it the battery/alternator?

 

We need a little more info than that. When you turned the key, did anything happen at all? Did it click once, several times or crank very slowly and just wouldn't light off?? How old is the battery and how cold is it near you right now?

 

it was about 38 degrees F. and it cranked slowly. im not sure how old the battery is i just got the car 8 months ago.

its a 95 maxima

 

Okay, that sounds like your battery is very weak. The only question is why. Is it at the end of it's life, or is the alternator not charging it as it should? Autozone and similar stores offer free testing on batteries and alternators. I would take it there and have them take a look to see which one needs to be replaced.

Also, does it look like a Nissan battery? If so, it could very well be original.