We're all aware that we shouldn't be running a million tabs at once, for the sake of our own sanity, but it's also a wear on your system resources. Wired decided to take a look to see if that also has an effect on your laptop's battery life.
To figure out what the effect of open browser tabs is on a laptop's battery life, Wired tested a Mac laptop running OS X 10.8 and Chrome, Firefox and Safari. The result is that more tabs means more power consumption, but it's not by much:
So, if you have a 100 tabs open, your battery life will be about 1 hour shorter. But how much of a difference does just one tab make? Since there is the base power of the computer, this battery life per tab depends on how many tabs you have open. If I take the partial derivative of my time function with respect to n, I get the decrease in battery life per tab... The more tabs you have open, the less effect each new tab has on the battery life. This is because if you have a ton of tabs open, you already have a shorter battery life.
Chances are that none of us have 100 tabs open at once. It's probably safe to say we can continue opening as many tabs open as we want without worrying too much about battery life.
Browser Tabs and Battery Life [Wired]