Gamry Interface 5000, Operator'S Manual, Page: 79 / 86

Appendix F: Heat in Interface 5000 Multichannel Systems--Single Interface 5000
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Note that the maximum power drawn from the instrume nt’s power input jack is largely independent of the cell
voltage. The maximum output power is power-supply voltage times the maximum cell current. The higher
power levels mentioned above occur because the battery is sourcing power. The output power plus the
quiescent power of 9 W divided by the power-supply efficiency of about 75% gives us a maximum input power
of 73 W.
Single Interface 5000
Gamry tested a single Interface 5000 operating at its most extreme working condition: discharge of a 6.5 V cell
at 5 A current. The unit was run in its normal horizontal position, with 5 A cell current, and a 6.5 V cell voltage.
The air-flow through the unit was unimpeded.
In this test, the unit could be operated with reduced power-supply rails indefinitely, with no over-temperature
events seen, even with a 45°C ambient temperature. The highest temperature measured on the outside of the
Interface 5000 chassis was 16°C above ambient.
Gamry has also tested a single Interface 5000 operating at its most absolute extreme condition. In this test, we
discharged a 6.5 V cell at 5 A current using the normal power supply, 8.6 V. The total power dissipation under
the test conditions was 84.5 W. The unit was run in its normal horizontal position with the air flow unimpeded.
The ambient temperature was 25°C. An over-temperature event occurred in approximately 30 min. It caused
the cell relay to open and stop the test.
If the same test was run at 45°C ambient temperature, the over-temperature event would have occurred
sooner, most probably in less than 8 min.
Vertical Stacks
Gamry also tested a system with four Interface 5000s stacked one atop another (a vertical stack of horizontal
units). In this configuration, the Interface 5000s run hotter, because power dissipation in one unit can radiate
heat to adjacent units and also preheat the air used to cool other units. The units higher in the stack run hotter
because their cooling air is preheated by the units below them. The cooling air entering the unit on the bottom
of the stack is unheated, so this unit runs significantly cooler than all the others.
All four units ran in galvanostatic 5 A charge mode with a 0 Ω cell. No over-temperature events occurred during
a three-hour test. The highest temperature measured on the outside chassis of the second from the bottom of
the vertical Interface 5000 stack was 26°C above ambient.
Interface Power Hub Systems
The Interface Power Hub uses forced-air cooling to lower temperatures in stacked Interface 5000s. The units
are turned 90° to run in an array of vertical instruments.
Gamry tested a system with eight Interface 5000s mounted in an Interface Power Hub. All units were operated
at the following test condition: All eight units ran in galvanostatic 5 A charge mode with a 0
Ω cell and normal
power-supply voltage of 8.6 V. The total power dissipation per unit was 52 W.
In this test, the system could be operated indefinitely with no over-temperature events seen, even with a 45°C
ambient temperature. The top of the Interface Power Hub chassis got warm, but stayed at less than 20°C above
ambient.