Im new to the whole 12th scale class. I got a good deal on a 12r5.2 with a 1s Trinity and notice that the first 2 laps the car has good punch off the corners and down the straight away but after that I feel
its starts to weaken. Does this got anything to do with the 1s battery? Is there such thing as them loosing power over time? (They are used batteries. Dont know how long they have been used but They came with the bundle)

I’m also new to 1s, other then small scale. Yes, over time batteries can loose the capacity/power. Usually shorter runtimes or lack of power is a sign. From reading here, a lot will replace batteries once a year when used under racing conditions

im just going to buy new ones. Im pretty sure thats the issue with mines.

You might want to check the sensor wire between the esc and the motor. I had an instance when this came loose and slowed the car down.