Super capacitors offer huge electrical storage in small packages. The YouChoos’ SuperCap 17000uF is rated at a whopping 17000uF/15V, but measuring only 20×15.5×5.8mm in a convenient flat block shape. Ideal for use with ZIMO MS450 and MS440 type sound decoders or any other ZIMO decoder that has built-in support for a 16V stay alive device. It can also be used with other decoders, but would require the use of an additional charging circuit.
Suitable for DCC systems where the track voltage is 15V or less (most, but probably not large scale).
You can expect between 1 and 5 seconds backup time from this capacitor, depending upon the model and what it is doing at the time of power loss.