The project of new accelerator complex NICA relating to nuclear and hadron physics require a more powerful longitudinal and transverse cooling that stimulates searching new technical solutions. The new accelerator complex NICA is designed at the Joint Institute for Nuclear Research (JINR, Dubna, Russia) to do experiment with ion-ion and ion-proton collision in the energy range 1-4.5 GeV/u for studying the properties of dense baryonic matter at extreme values of temperature and density with planned luminosity 10²⁷ cm⁻²s⁻¹. This value can be obtained with help of very short bunches with small transverse size. This beam quality can be realized with help of stochastic and electron cooling at energy of the physics experiment. The electron cooling system on 2.5 MeV consists of two coolers, which cool both ion beams simultaneously. The Budker Institute of Nuclear Physics (BINP SB RAS) has already built and commissioned the electron cooling system for the NICA booster, and now it develops the high voltage electron cooling system for the collider. The article describes the construction and status of the cooler development. Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil
