After doing some literature review and learning about hybrid lithium-ion (super)capacitors (LICs) which I detail in my most recent blog, it has come to my attention that such capacitors have a minimum voltage and this is actually the voltage that the capacitor should never go below or risk permanent damage, failure or even potential safety issues. Such capacitors are shipped charged to a certain level and should never be short circuited. This is similar to how lithium-ion batteries have a minimum discharge voltage below which you should never reach.
As part of our kit, we received two of each: VMF406M3R8, VMF256M3R8 and VPF406M3R8 supercapacitor which are LICs.
Unfortunately, it seems, that during shipping, the capacitor legs may have touched and likely shorted at some point . As a result, three of the six LICs I have are reading below minimum voltage at 0.003V, 0.008V and 0.911V. The other three are fine at 3.364V, 3.316V and 2.607V. This does mean that both of my VMF256M3R8 are in the below minimum voltage category.
As a result, I would advise all challengers to measure the voltage of their capacitors and see if they are still above the minimum voltage of 2.5V (VMF) or 2.2V (VPF). If so, then keep them separated in a way that would not be able to short circuit and use them well. If not, then perhaps those capacitors have been damaged by this and may not achieve the same level of performance as promised, or perhaps they could even be (slightly) dangerous as I found one datasheet that suggested removing from use immediately while another seemed to suggest that such LICs were immune to thermal runaway failure so a lithium-ion battery style "vent with flame" is not a possibility. I'll probably still use mine anyway with the note that they have been abused.
Nevertheless, do let me know whether your capacitors survived the trip or not ... and in future rscasny , srutledge and even the element14/Newark/Farnell shop to take note that hybrid LIC supercapacitors are shipped charged and cannot be short-circuited, thus "loosely" placing them into a compartment or even into a conductive bag or foam is likely to be a bad idea.
