Welcome to a laptop battery specialist of the Acer Laptop Battery
The cooling fan inside the Ultra M3 stays running most of the time and remains virtually silent during all but the most demanding activities. The fan gets loud enough to disturb other people in a small office or classroom if you're stressing the graphics with a game like Mass Effect 3 or Batman: Arkham City but you probably won't notice the cooling fan the rest of the time.
External temperatures are all pretty modest with the exception of a very nasty hot spot located near the RAM, mSATA SSD and Wi-Fi card which reached a maximum external temperature of 112 degrees Fahrenheit. This hot spot gets very uncomfortable over time and makes it difficult to use the Ultra M3 as a "laptop" at times. I suspect the real culprit is in fact the mSATA SSD, but regardless of which component is responsible for the heat, the thin chassis of the M3 just lacks the thermal design needed to properly manage that heat coming from this central location. Keep your legs away from the middle of the ultrabook and you should be fine. Interestingly enough, the temperatures of the CPU and GPU remained perfectly normal during our tests so at least the chassis is managing the heat for these components.
The Acer Timeline Ultra M3 lasted for 8 hours and 38 minutes of continuous web surfing during our standard battery like Acer Aspire 1300 Battery , Acer BTP-APJ1 Battery , Acer BTP-AQJ1 Battery , Acer BTP-ARJ1 Battery , Acer BATCL32 battery , Acer BATCL32L battery , Acer Aspire 2000 battery , Acer Aspire 2016 battery , Acer Aspire 2200 battery , Acer BATBL50L6 battery rundown test (Windows 7 Balanced power profile, 70% screen brightness, wireless active and refreshing a web page every 60 seconds). This isn't just good, it's amazing battery life when you consider this also has a powerful discrete graphics card inside. Of course, the GeForce GT 640M features NVIDIA's Optimus technology which automatically disables the graphics card and runs the display on the low-power Intel integrated graphics when the notebook isn't displaying visually intense content. That being the case, the NVIDIA graphics were automatically turned off during our web browsing battery exhaustion test.
Regardless, the important thing to note is that the Ultra M3 exceeds Acer's claim of "8-hour battery life" and that's impressive. Your mileage may vary if you buy the configuration of the Ultra M3 with a more power-hungry Intel Core i7 processor, but the run time from the integrated 3-cell lithium-polymer battery should still be excellent.