LED science fair question

[hsp]

We are doing the old fruit cell battery science fair experiment. Our fruit is generating 1.54V. How is it possible that we are able to power an LED that is 2.4V, 20mA? Granted, it is only emitting a faint light, but it seems to us that it shouldn't work at all. Please help this mama.

 

[BobK]

2.4V and 20mA is just one point on the I/V curve of the LED. It will draw less current at lower voltages and more current at higher voltages.

Bob

 

[(*steve*)]

What would happen if you had 2 pieces of fruit?

Could you connect them in such a way that the voltages were added together?