Battery management systems for energy storage devices

A system for storing energy, comprising:

• an energy storage device comprising an electrochemical cell having a negative electrode, a positive electrode and an electrolyte between the negative and positive electrodes, wherein at least one of the negative electrode, the electrolyte and the positive electrode of the electrochemical cell is in a liquid state at an operating temperature of the electrochemical cell that is at least about 250° C.;
• and
• a controller in electrical communication with the energy storage device, wherein the controller includes (i) a central processing unit (CPU) that is programmed to monitor and control an operating state of the electrochemical cell, (ii) a terminal block that receives power from an auxiliary power source, and (iii) a filter that receives the power from the terminal block, steps down the power to about 12 Volts direct current (VDC), 5 VDC or 3.3 VDC, and transmits the power to the CPU.