Sometimes, my tools will not drain energy from the batpack, and other times, the tools do not drain energy at all shortly after removing the batpack. This is usually fixed by removing and replacing the batpack. When this happens, it is not just my electric tools that do not lose energy - all the other standard vanilla and bronze tools I tested did not lose durability while this bug was active, but as soon as I fixed it again by removing/replacing the batpack, all tools functioned normally. While restarting minecraft doesn not help, reinstalling IC seems to fix this bug temporarily, this being my first instinct when I first encountered the bug.