Let me say this first. I LOVE my iMac (and the love affair is mutual)!
But one thing I've noticed rather quickly. This "thing" eats batteries for breakfast but because I've used a WACOM tablet, it was manageable.
That all changed when I started to do a lot of coding and scripting for HTML/CSS driven pages. It got so bad that I had to replace the batteries on a weekly basis which is not only expansive but also BAD for the environment.
Energizer to the rescue!
The other day I was browsing London Drugs and discovered that Energizer offers an inexpensive little gadget which comes with four rechargeable batteries. THAT WAS IT! I bought it right away and so far, all is well.
For the time being, I no longer work 15 hour sessions but still, this product is a God send. I wish every problem was as easy to solve!