Steam battery efficiency

Hi everyone!

I’m playing the Space Exploration + Krastorio 2 mod and I have a question about energy efficiency.

I originally built a steam battery system to deal with energy beam issues, but over time I’ve really started to like it because it seems to save a lot of materials and space compared to regular accumulators.

The problem is that I can’t figure out how to properly compare their efficiency.

What’s the actual efficiency difference between accumulators and steam battery systems? Is there a clear way to calculate or estimate it?

Thanks!