Over at Tweaktown is a review of an upgrade for Ultrabooks, Patriot's 1.35V, 8GB DDR3-1600MHz at $45 for a single SODIMM.  The idea is that not only do you get a decent sized pool of RAM but because it sips 10% less power than a standard SODIMM you might just get a bit more battery life.  They tested out the memory on a Lenovo ThinkPad W530 with a 6-cell battery, not the longest lasting of setups and saw about a 10% increase in battery life as you might have expected.  That did only translate to an extra 17 minutes but as the laptop in question was only good for 4.5 hours of life, you can expect better return from an Ultrabook with a longer battery life.

"The big push in 2013 for mobile performance will be fought in battery life. Like every other market, if you want to get the best available you have to go to the aftermarket for premium components. The Patriot Memory for Ultrabooks will increase your notebook or ultrabook battery life, but just like everything premium, you have to pay a bit more."

Here are some more Memory articles from around the web:

Memory