When you're creating a batch in Accelerlist, you shall see the estimated weight of the batch:

This information is as per the Amazon API, and it isn't always accurate.
We at Accelerlist do not determine the weight of the products ourselves.
Thus. we recommend keeping a weighing scale handy to check product weight while creating a batch so that you add products within the given weight limit which is 40lbs for a single Box in case of Box Content.
If you're looking to do an LTL Shipment, learn more about it here.