Epoxy nickel nanocomposites were prepared. Water droplet initiated Corona inception voltage (CIV) on epoxy nanocomposites were obtained through Ultra high frequency (UHF) technique, under AC and DC voltages. The discharge signal generated due to water droplet initiated discharge has dominant frequency content at around 1 GHz. CIV and contact angle increases with addition of nickel nano filler percentage in epoxy. Laser induced breakdown spectroscopy (LIBS) gives the elemental composition in the polymer matrix and plasma temperature variation is calculated. Dynamic mechanical analysis (DMA) studies were carried at different frequencies. It shows an increase in storage modulus and reduction in loss modulus with nanocomposites. The activation energy and the glass transition temperatures shows better value for 3wt% of nano nickel in epoxy resin. © 2020 Institute of Electrical Engineers of Japan. All rights reserved.