Starcap battery-cap replacement?

[slap_happy]

I'm looking to confirm the type of a capacitor, if it is indeed a capacitor.

This Starcap "battery-cap" thing looks like a button battery but is labeled with what appear to be capacitor values.

It has leaked some crusty stuff out along the edge. I cleaned it up with some rubbing alcohol but some of the crust can still be seen along the edge in the top right of the photo.

It is in a consumer electronics device that has been in use for 9 years.

It is labeled;
Starcap
0.22F (note, not "uF")
5.5v
DC +70C

What is this thing and what might be a good replacement?

[Per Hansson]

Re: Starcap battery-cap replacement?

It's called a supercapacitor or ultracapacitor.
Used instead of a battery for things like RTC and the likes.
They have quite poor lifetimes and often leak.
If the device does not require a good clock or whatever the capacitor is used for you could just replace it with a regular electrolytic: thus saving the trouble of having it leak again...

If not then this category should give you an idea what to look for:
https://www.digikey.se/product-detai...1023-ND/970184

[mariushm]

Re: Starcap battery-cap replacement?

It's a super capacitor

It's 0.22F or 220mF ... 5.5v

You can replace it with anything of that voltage rating or higher, and a capacitance value close to that value or higher. It's basically there pretty much to power a ram chip or something that keeps some settings for some time, until the unit is plugged again (and then power supply takes over and refills the super capacitor)

Here's options: https://www.digikey.com/short/pphqpf

Pretty much any of them would work, but you'd probably want one that sits flat like the one in your picture. You have that capacitor near the super cap, so probably you could put there capacitors mounted vertically but double check that.