At Act 1 of the game. The Announcer says this:
"Well done! The Enrichment Center reminds you that although circumstances may appear bleak, you are not alone. All Aperture Science personality constructs will remain functional in apocalyptic, low power environments of as few as 1.1 volts."

In Act 3 Potato GLaDOS says this:
"No tricks. This potato only generates 1.1 volts of electricity. I literally do not have the energy to lie to you."

My thoughts: Aperture was planing to use potato batteries as an emergency power source?

Probably set to output 1.1 vots by wheatley to make sure glados survives (suffers) in the potato.

I have a feeling they recorded that line back when they were planning to have multiple personality core characters throughout the game. But I guess now it's an excuse for a potato being able to power an artificial intelligence such as GLaDOS.

iWork925 wrote:
Probably set to output 1.1 vots by wheatley to make sure glados survives (suffers) in the potato.

You don't 'set the voltage' of a potato/lemon battery. You get however much current is generated and that's it. Voltage also varies depending on the size/natural energy content of the potato/lemon

Where did GLaDOS get the energy to find out the potato was only 1.1 volts? Hmmm