Surface Pro 3 short battery life

The Update 2 that came across did not address the overheating issue with the i5 and i7.  That will still be a problem but will keep people from over tasking the tablets and should get good battery life.  The i7 model could possibly get about 5 to 6 hours per charge with basic use.  If the i5 already gets that, that may mean that each model may have different battery packs to support the processor type.  Only the i5 was dismantled by ifixit.com and no details on the i3 and i7 models.

All three are exactly alike otherwise.

The over heating issue is still being investigated and will probably be worked on for the next update cycle.

Now, I do have the i3 CPU and not the i5.  The i5 has a lot more "under the hood" plus it also has Turbo Boost which kicks in automatically when needed (no control for that).  The i5 is the only one in the "Haswell" family that has that feature.

The i3 is much like a Celeron compared to a Pentium.  The tablet does clock in almost as fast as the i5 in most situation.  I am surprised in how much speed I am actually getting from it.

Now, also remember that you streamed videos.  When I ran mine on battery, I only watched one video and that was the latest episode of "Falling Skies" in Xbox Video.  When you stream videos on the Internet, that cuts your battery life down quite a bit because of the demand made on the WiFi adapter to maintain bandwidth.

So, in your case, it is not the screen brightness that is cutting you down.  Constant web browsing can cut you down as well.  Again, you are tasking the WiFi adapter.  Networking adapters use more power than other devices because that is how they work.  No way around it.  Bluetooth is part of the Marvell adapter but eats little as long as it is only controlling a keyboard or mouse.  You use a headset or sending output to a Bluetooth printer and then it eats power as well.  There are some things you cannot trim on or the device would not work.

I have worked with i5 laptops quite often and 4.5 hours would usually be the maximum they would run on battery.

Now then, you are probably going by the 'supposed' 9 hour battery life potential that was advertised.  That was most likely an i3 model with no keyboard and the machine was only turned on and not used.  That is usually the method of battery life tests with computers.  Don't go by that.  Nobody can ever guarantee the recommended life limit because another factor is involved as well - the batteries themselves.  No two batteries are exactly alike.  Lithium-Ion batteries are also unpredictable.

Good points. I would recommend plugging in when watching videos online

I was wondering if I have a defective unit. I have an i5 surface pro 3 and I only get about 4 hours of battery life playing YouTube videos at about 40 % brightness and about 5 hours of web browsing.  The computer shuts off when I am just below 10 % battery left. What are you guys getting?

Thank you in advance for your help.

Best regards,

Jordi

Please, read this guide:

http://www.surfaceforums.net/threads/guide-all-about-battery-life.10374/#post-75782

Thank you very much for all you information and advice, James.

Have a good night!

Best regards,

Jordi

That is an electrical short, then.  If it is unpredictable when it will happen then random malfunctions tend to be a short somewhere on the motherboard.  You should have no screen lockup for any reason.

In that case, get your data off the tablet and trade it in.  Keep the keyboard and swap out the tablet only.