1. Home
  2. Electronics Design
  3. Failure mode of supercap at overcharge?

Failure mode of supercap at overcharge?

Hi, I have an application - a servo power supply for an extremely cold (-50 C) environment - where I need to buffer the battery with a supercap in order to get the ESR low enough. Since the application only has to live for like 100 hours and the temperature is so low, I thought maybe there will be no penalty for overcharging one supercap to 4.5 volts? Does someone know the failure mode of supercaps at overvoltage - is it catastrophic or is it just the lifetime that will get impaired? Regards, Soren

Reply to
soren.kuula
Loading thread data ...

Dunno if you are in the US, but Digikey seems to have one that should work for you.

formatting link

For $12.24 you get 33mF 150mOHM 4.5 volts.

If that's too much money maybe you could specify your needs a little more c learly. If the problem is mainly high frequency you don't need as much capa city. Of course that depends on the current. Even in supercaps a lower capa city will save money, I don't feel like the math right now but a thirtieth of a Farad is ALOT. I mean bypassing one Hertz or something at probably mor e current than the battery can produce would be no sweat unless you are usi ng a huge battery, but then you wouldn't need this, right ?

Then there is the voltage rating. If you need 4.5, it would be a better ide a to exceed the ratings (grrrr) of say a 4.0 volt than a 2.5 volt for examp le.

It all works against the money. The $12.24 cap would definitely do it, but so might many cheaper ones.

Reply to
jurb6006

Probably electrolysis of the electrolyte. Some organic ionic liquid or something. Kind of like overcharging lithium ion cells.

Tim

-- Seven Transistor Labs Electrical Engineering Consultation Website:

formatting link

Reply to
Tim Williams

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.