Metal Hydride - An intermetallic compound or alloy in which hydrogen has been absorbed; also, the negative electrode in a nickel-metal hydride battery.
Top-Up Charge - A low rate charge following the main charge, designed to ensure maximum capacity.
Earthing system - System for the interconnection and earthing of exposed conductive parts and neutral. There are three types of neutral system - IT, TN, TT.
Positive Temperature Coefficient (PTC) - A thermally reactive device which becomes highly resistive at a specific temperature or current.
Bobbin - A cylindrical cell design utilizing an internal cylindrical electrode, and an external electrode arranged as a sleeve inside the cell container.
Short-Circuit Current (SCC) - The initial value of the current obtained from a battery in a circuit of negligible resistance.
Static bypass switch - Power-electronics device that can be used to switch from one source to another without interruption in the supply of power. In a UPS, transfer is from Mains 1 to Mains 2 and back. Transfer without interruption is possible due to the fact that there are no mechanical parts and the ultra-fast switching capabilities of the electronic components.
