converting some solar powered garden lights

[cool-agent]

I am looking at converting some solar powered garden lights I have, from amber LED's to superbright blues.
The lights are powered by 2 NiCad cells which charge up from solar panel.
The power supplied to the LED's is 2v.
The superbright blues require 3 to 3.6v.
Is there anything I can put in the circuit to boost the voltage?
I know it is possible as I have checked out one belonging to a friend, which was bought with a blue LED in it. This one runs on a single NiCad cell but the voltage reaching the LED is 3v.
A small circuit board is inside and the output has 2 items linking to it, one is a capacitor, the other I dont recognise.
I am not very "up" on electronics maybe you can help.
The voltage measured from battery neg. to one end of the mystery item is 3V, the other end is battery voltage (1.2V approx) Voltage measured at the Capacitor is 3V at one end (same board track as mystery part) and 0V at the other end.

 

[Optikon]

I am looking at converting some solar powered garden lights I have, from amber LED's to superbright blues.
The lights are powered by 2 NiCad cells which charge up from solar panel.
The power supplied to the LED's is 2v.
The superbright blues require 3 to 3.6v.
Is there anything I can put in the circuit to boost the voltage?
I know it is possible as I have checked out one belonging to a friend, which was bought with a blue LED in it. This one runs on a single NiCad cell but the voltage reaching the LED is 3v.
A small circuit board is inside and the output has 2 items linking to it, one is a capacitor, the other I dont recognise.
I am not very "up" on electronics maybe you can help.
The voltage measured from battery neg. to one end of the mystery item is 3V, the other end is battery voltage (1.2V approx) Voltage measured at the Capacitor is 3V at one end (same board track as mystery part) and 0V at the other end.

You could build a small boost regulator.
Check linear tech or maxim's websites. They have integrated circuits that you can wrap a few components around to get your desired output voltage. They have app notes & datasheets which walk you through the whole design process. It will require a couple of small parts. This is certainly feasible for running LEDs. Most parts you need can be ordered from digi-key or mouser at rip-off prices.

On the other hand, it might be easier to just retrofit another NiCd cell in series with your existing ones.