Cermant 2 pcs 8.5X17X14mm(0.33x0.67x0.55in) Super Capacitor 5.5V 0.47F Super Farad Capacitance Winding Type Energy Storage for On Board Backup Energy Storage Combination Vehicle Recorder

I got these mostly just to play with. They work fine powering a 5-volt PIC processor circuit for several minutes after disconnecting the AC supply. I will probably use them as a mini-UPS for small projects to ride-out any momentary AC power failures.

Didn't work for what I was trying to do, but the only draw back negative is the physical size of these. They nearly take up the center of my palm. I found using a smart charger 3.7 v for lithium ion batteries - capable of putting a charge on these which rests around 4v which might be the top of the charger actually, before it cuts out. You can then hook up an LED to this and it will power it independently of the wall charger for about a minute or two - depending upon the size of the LED of course. I was testing it on a flat bar style LED rated at 5v. Unfortunately, you have to unplug the charger and reinsert the 2.1mm plug into another item (adapter with screws for wires) to get it to pick up a charge again. It won't automatically tell the wall charger to kick in by itself. Not like a traditional battery.

Both worked. Simple as.

Made a battery replacement for an MTH steam engine out of these. The original battery was a 2.4V Nicad inside the tender and this replacement BCR2 is permanent. I used a JST-PH 2.0 connector attached to the (+) and (-) leads of these supercaps and plugged it directly into the PCB after removing the battery and harness. Inexpensive upgrade and I have a spare for another project.

I’m refurbing an old Stern Pinball machine with an 8 bit microprocessor. They originally soldered a nicad battery to the board and they would leak and do all sorts of damage. I read on a pinball forum the recomendation to replace the battery with a super cap so I did. I used both caps in parallel so it’s a total of 2F worth of capacity. Its cool to watch how slowly 2 farads takes to charge up, perhaps an hour or so. After a day or so of being turned off, the voltage only droped a couple of tenths of a volt.