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No cold or hot issues with Amperics Ultracaps

Data sheet performance across the entire operating temperature range.

Among the most difficult issues to contend with while sizing an energy storage device is the performance of the device when the operating temperature deviates from the standard temperature of 25C.

Lead acid batteries have a dramatic loss of energy as temperatures drop to zero degrees centigrade and below. This while the data sheet indicates an operating range of -20C to +60C and a charging range of -20C to +50C. Common work arounds to this issue are to heat the batteries using a gaseous source to keep it at an acceptable level.

Li-Ion batteries have the opposite issue. Not only does Li Ion have a smaller operating temperature window they are flammable making it a significant safety issues. Expensive thermal management solutions are required them to safely implement Li Ion technologies in environments that routinely reach or exceed the upper operating temperatures. This has to do with the fundmental mechanism of energy storage used in batteries: A chemical bond which is fundamentally effected by the temperature.

Supercapacitors in contrast have a nearly flat performance profile over the operating temperature. This is in addition to having a wider operating temperature of -40C to + 65C. As can be seen in the graphs below, Amperics technology has been characterized over temperature and charge rates and demonstrates a WYSIWIG characteristic to supercapacitor performance. This has to do with the fact that energy storage is accomplished in supercapacitor using a voltage gradient and is largely  independent of temperature.

This is significant consideration for any deployment of energy storage over wide operating temperatures.

             Temperature         ENERGY DENSITY (Wh/KG)        POWER DENSITY (kW/KG)
                  -30 °C                         27.1                      16.8
                     0 °C                        34.7                      22.4
                   23 °C                       32.9                     25.6
                    50 °C                       39.1                      32.

 

EDand PD based on total electrode weight.

X-Axis – C Rates for Charging, Y-Axis – whr/kg based on total electrode weight.

Battery type                           Charge temperature                    Discharge temperature

Lead acid                            –20°C to +50°C                                    –20°C to +50°C
NiCd, NiMH                           0°C  to +45°C                                     –20°C to+ 65°C
Li-ion                                      0°C  to +45°C                                     –20°C to +60°C

Amperics Supercaps          -40C  to +65C                                        -40C  to +65C