Volt acquired WA crushing business Wescone in January 2018 for A$5 million plus a royalty.
However, in September long-time customer BHP informed Wescone it no longer required its services.
Wescone had provided crusher repair services for the BHP-owned fleet of Wescone W300 sample crushers for the past 25 years.
The writ seeks a court order for damages, including interest and costs for breach of contract and/or that agreements relevant to Volt's acquisition of Wescone are void for misleading and deceptive conduct and acquisition monies must be refunded.
"The Wescone writ has been filed on the basis that material information in relation to the BHP relationship with Wescone was not disclosed to Volt prior to Wescone acquisition completion," Volt said.
Volt said it would keep shareholders updated on the matter.
The company also owns a waste heat to electricity generation equipment solution, and 50% of EcoQuip, a mobile solar lighting and communications tower solution.
Volt was previously heat-to-power company Enerji, but relisted on the ASX last year following a recapitalisation.
Private construction and maintenance company ECM is Volt's largest shareholders.
Volt last traded at 0.2c, valuing the company at less than $16.5 million.