It's hard to say since I mostly use it for heavy-drain stuff. Streaming movies on Netflix, building apps in Android Studio, etc. Always have Chrome running with a ton of tabs.
I'd say 6h of use in Ubuntu. The reviews I read say that the battery is better using it with Windows 10 (closer to 10h) but I just can't get my work done in Windows.
Overall the battery is not disappointing. Not sure if I can change the battery by myself but for $750 I don't intend to invest much in repairs. I'll just ride it until it dies.
I also have UX305 and I easily get at least 6 hours under moderate loads. Eight or nine with light web-browsing (avoiding javascript pages that spike cpu usage), ten or more with lighter use (text editor).
I installed Ubuntu 14.x and i3 window manager. I have dual boot with original Windows install and power use is comparable between Windows and Linux. It's a pleasure to use. Only power management tweak I made in Ubuntu was to install the TLP power management tool and (I think) make simple change from its defaults: http://linrunner.de/en/tlp/tlp.html
EDIT: Mine is a UX305FA, the one with less powerful Core M processor. It's slightly slower than my Thinkpad x220, which has an older i7. So it's not a powerful machine, and I assume less powerful processor means better battery life than the faster x305's that have come out since I got mine.
I don't remember. I would check power usage with powertop and make sure you've got no 'bad' indicators on the 'Tunables' tab (actually I think I still have one bad). On the 'Device Stats' tab you should be able to get 'system baseline power usage' under 5 watts under light loads. I run mine with display brightness fairly low, 20% or 30%, but it's still has comparable brightness to my other main laptop's (Lenovo x220) full brightness.
I actually have a Lenovo x220 as one of my machines, and with 70-80% brightness I get about 4 hours of battery life (wifi included) on a 9 cells battery. Does it sound reasonable or am I not getting what I should?
Sounds about right, I have 6 cell in my x220 (with Win7) and I'd guess its life is around 2.5 hours with those settings. It's short enough that I don't feel comfortable using it on the go, keep x220 at home almost always plugged in to AC. The battery difference between it and the UX305 is huge.
The x250 has great battery life. The keyboard is a little better than the X240, but not as good as the X220 or even the X230. Some of the keys are not full size. The function keys are garbage by default, but there's a persistent Fn lock (might be a BIOS setting, don't recall).
Performance wise it's very nice. Screen is decent, too. My only complaint is the that the keyboard has a bunch of non-full size keys. End and Insert are on a single key. Someone should be shot for that.
I have the x220 with a used 9-cell battery (last full charge was 75%) and I'm easily able to get just under 6 hours of standard use (browsing, WiFi, watching movies, coding) and screen brightness at around 60%.
I'd say 6h of use in Ubuntu. The reviews I read say that the battery is better using it with Windows 10 (closer to 10h) but I just can't get my work done in Windows.
Overall the battery is not disappointing. Not sure if I can change the battery by myself but for $750 I don't intend to invest much in repairs. I'll just ride it until it dies.