Training a CNN on a large dataset
Changing the batch size will not change the overall training time too much. Since with any batch size you are passing almost 80K images.
One(and the best) approach will be to use transfer learning.
If you have a compelling reason to do full training, you will need a GPU powered bigger hardware. Google Colab can be an option. There are many other options available
Before that you may try to gauge the model with a sample of ~5k images