Easy to reproduce, see below.
After just few seconds and on/off 4000 energy disapired. You cant even see this lose on cycle report.
You MUST fix this BUG.
Steps to Reproduce
1. Build power circuit with one full smart battery. 2. Connect it to the Large Power Transformer input. 3. Output connect to the second full smart battery. 4. Connect any green/red automation source to the Large Power Transformer. 5. Make green signal to charge Transformer and drain 4000J from first battery. 6. After make red signal - 4000 J disapired from Transformer.
This issue has been fixed in either a future version or updated in a previous version.