export to smaller file size has boudary?

Hi,

How to get the files size even smaller?

I have an image (3 MB) that I want in a smaller file size (150kB). But in PS the export as jpg quality setting makes the file output 350 kB. Also tried script/image processing / quality setting to 1, same result around 350 kB. 

There must be a way to compress even more? 

Also I want to do this in batch for a series of images, so if the solution could be able to, that would be great.