This Capacitor is available as part of Lego’s eLab Dacta range.

It is available from the Commotion Group, Bricklink and other Dacta distributors.

Its part number is 32342 and it comes in set number 9916-1 (as well as 9685 Green Car Set and 9684 Renewable Energy Set.

Set information from Peeron.

According to lego it is a 1F (as capacitors go that’s huge by the way) 2.5V capacitor.

Other specs

  • Charging voltage maximum 4 V
  • Maximum charging and discharging current 0-250 mA
  • Red LED indicator when fully charged at 2.5 V
  • Protected against reverse polarity; capacitor will not fully charge
  • Charged to 2.5 V, the capacitor will store about 3.125 joules of energy

It is not waterproof - so precautions should be taken.