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

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 tested one with a lightbulb and 3V battery. The light went out as the capacitor charged and then lit up when the battery was shorted out and the capacitor discharged. That's what I need for my physics students to be able to see.