The batteries are HEAVY and hard to just deadlift out of the box.
@Will Prowse can chime in since we just replaced 2 of the prototypes he had with production models. He will test our strategy.
We heavily considered how important keeping the box together for returns would be. Since the shipment would have to be returned via freight, the structure of the box is not such a big deal since most of the protection comes from being strapped to the pallet. If we were sending ground, that would be a totally different scenario.
In ~90% of cases if the battery doesn't work, it's either something that we can get repaired easily in-field, or severe shipping damage where a FedEx would be paying a claim out for a replacement. In this case, we probably wouldn't want to ship a damaged battery...HAZMAT regulations would be on us in an instant!!!
For the remaining very small fraction we could send an empty box if push came to shove. At the end of the day we would make sure a return is handled properly to keep everyone and everything safe.
We would rather the greatest majority of cases where stuff arrives in perfect condition be safely unboxed. It's not worth saving a $3 box to risk dropping a $1700+ battery. Imagine if that battery fell on your toe because you didn't have a good grip on it. That's a trip to the ER that could cost more than the whole system!