Board Thread:FAQs/@comment-26395021-20150519000208/@comment-26018514-20150519155738

Phantomlink959 wrote: The hammers are presumably rechargable like the plasma weapons are, humans are simpy unaware of how to recharge them, meaning in human hands a gravity hammer IS limited to the number of hits it can deliver.

Also, the Fist of Rukt was some sort of religious relic for the Brutes if I recall correctly, they probably put a longer lasting battery in it. or it was actually made by forerunners that knew how shit worked while the rest are reverse-engineered copies made with minimal understanding of the underlying tech.