New Delhi: Lithium-ion battery pack maker and recycling firm Lohum on Wednesday said it has secured USD 54 million (Rs 450 crore) in a funding round from a bunch of investors. The investors who participated in the series B funding round of capital infusion include Singularity Ventures, Baring Private Equity, Cactus Venture Partners & Venture East amongst other new and existing venture firms, Lohum said in a statement.