13" Haswell Battery Life Issue

aminadab said:

Just got my BTO, 13" base model with 8GB ram. After setting things up, I'm noticing that at 80% capacity, monitor at 50% with only Safari and Mail open, the machine calculates 5 hours of life left. I did an SMC reset, along with the PRAM.

I've had the computer for less than an hour, perhaps the machine isn't yet accurately measuring its power? Any ideas?

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The "time remaining" indication is an ever-changing estimate, based on the current workload of your system. It will fluctuate up and down from minute to minute as your power demands change. It is not perfectly accurate, but only an estimate. There are many factors that impact your battery life. See the BATTERY LIFE FROM A CHARGE section of the following FAQ link for details, including tips on how to maximize your battery life. Also, on a brand-new Mac, Spotlight may be indexing your drive, which will consume system resources and drain your battery faster.

PRAM/NVRAM has nothing to do with battery/power/charging issues. Resetting it will not help. Only resetting the SMC addresses such issues. The link below should answer most, if not all, of your battery/charging questions. If you haven't already done so, I highly recommend you take the time to read it.

aminadab said:

I've had the computer for less than an hour,

Any ideas?

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Use it for more than an hour:

1.) Charge it to 100% and unhook charger.
2.) With Pencil and Paper, look at clock and note time. (A pen will work)
3.) Use machine normally until it dies
4.) look at same clock in step 2. Record time.
5.) Subtract time in step 2 from step 4.

How much time did you really get? Seriously. Some of you guys take that little estimate way too seriously. It's only a "guess" (and usually a bad one at that).

On my 15" I noticed that the OS seems to take a while to "settle down" when the machine is new. I don't know what it's actually doing, but if you watch CPU usage you'll may see that a number of processes are randomly grabbing CPU time. Some kind of first-run optimization or background if I had to I guess, but I don't actually know what it's up to. Maybe data collection for debugging? I believe even if you disable automatically uploading this data to Apple it's still collected to the OS.

After a few hours of usage it settled down (at least on mine) and the battery life estimates improved significantly.

Also, do exactly what's suggested in the post above. That estimate you see is based on what's going on at that exact time (I think it uses like 1 or 2 minutes as the sample time) and will vary massively. The only way to really know is to do a little basic math.

Seems normal to me