I have similar battery life these days. My battery is only charging to 29.9 Wh. Our machines are nearly identical minus the nvidia gpu. I was thinking about grabbing this battery on amazon with a design capacity of 94.4 Wh.
http://www.amazon.com/dp/B0085MPGDG/ref=wl_it_dp_o_pd_nS_ttl?_encoding=UTF8&colid=5DWC76XAQWGE&coliid=I3R5VWD5PK3CB3

On the machine you should try to run the brightness as low as you can stand, double check that the cpu is idling at the lowest frequency, and disable anything you don't use (bluetooth, etc).

CORSAIR ValueSelect 16GB (2 x 8G) 204-Pin DDR3 SO-DIMM DDR3 1333 (PC3 10600) Laptop Memory Model CMSO16GX3M2A1333C9

Lenovo 0A36303 , Thinkpad Battery 70++, 9 Cell High Capacity Retail Packaged Lithium Ion Laptop System Battery -- purchased from seller "Amazon.com Services, Inc" and it appears to be a legitimate genuine Lenovo battery based on all the packaging and battery specs

Bought this machine brand new in 2011 and it hasn't yet given me a lick of trouble. The original battery has only been giving me ~1 hour of battery time, which is to be expected for an 8 year-old battery, so it seemed like it was time for an upgrade. The original 8GB memory was still serving me well as I only use this machine for web browsing, coding, and media consumption, but figured I might as well upgrade it all at once and enjoy the next 8+ years of service this machine should give me!

Here's a battery (https://www.amazon.com/gp/product/B0085MPGDG/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1) I've had one for 2 years and still get over 5 hours of battery life.

Intel Centrino Ultimate -N 6300 AGN

any intel, samsung or corsair drive I would recommend. They are the top of my list. I've got a 500gb 850 evo mSATA now as my boot drive.

Have you thought about upgrading your CPU? I've got a 3820QM in mine and get amazing performance. You might want to upgrade your HFS though.

No one seemed to answer this for you so I'll try my best. This modding guide has a lot of the best parts this laptop can use including battery! Although I'd be aware of receiving a fake battery on Amazon or eBay. On Amazon, it shows $60, but if you type the serial number it should be on the Lenovo website for more money. You'll have to decide what the best option for you!

Everything that can be done to the T430 and best upgrade options!

https://medium.com/@n4ru/the-definitive-t430-modding-guide-3dff3f6a8e2e

From Lenovo

https://www.lenovo.com/us/en/accessories-and-monitors/chargers-and-batteries/batteries/BATTERY-ThinkPad-Battery-70/p/0A36303

From Amazon

https://www.amazon.com/gp/product/B0085MPGDG/ref=as_li_tl?ie=UTF8&tag=n4ru08-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B0085MPGDG&linkId=5e4dd8bda2aaf0eacc084a43112aa656


Hope this helps

I'm using a 9-cell 70++ battery that I bought brand new. It's produced through sanyo for lenovo. It appears genuine of course and has a energy full capacity of 100%. Manufactured in 2018. https://www.amazon.com/gp/product/B0085MPGDG/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

My Plasma battery monitor usually says I'll get about ~3.5 hrs out of it when I turn brightness down which I think sounds way too short. My original battery was manufactured in 2012 with an 83% capacity but the battery monitor read the same thing.

You think this battery is legit? I've seen people getting 5-6 hrs from this battery with proper power management but I feel like I should return it and tell them to get me a better one.

what about this one? http://www.amazon.com/Lenovo-ThinkPad-Replacement-Battery-0A36303/dp/B0085MPGDG/ref=sr_1_1?ie=UTF8&qid=1426369764&sr=8-1&keywords=lenovo+t420+battery

I've bought two after market Thinkpad batteries (but not that one) with good luck so far (knock on wood).

I think most people would say stick to the Lenovo brand if budget allows.

As others have said, up the ram to 8-16 gb. Another thing I would think about doing is replace the battery. Often times refurbed batteries are terrible. I wouldn't reccomend third party batteries, as I have found the cells inside them are bad. I'd grab a 9 cell new lenovo battery from amazon: http://www.amazon.com/Lenovo-ThinkPad-Lithium-Battery-0A36303/dp/B0085MPGDG/

I also added a bay battery from ebay, but that's just personal preference.

In linux, install tlp, thinkfan, and the install the thinkpad kernel module. That software basically optimizes linux for the thinkpad. You will get much better battery life with all of that. Also, thinkfan will let you set the fan curve, and provides a better option for fan control on thinkpads compared to what is in linux out of the box.

Everything else should work just fine in Linux. Please note that 160 gb might not be big enough for both linux and windows. Linux will be fine with low storage, but windows is 20 gbs by itself. In addition, adobe CC is probably another 10 gb or so. Keep that in mind.

http://www.amazon.com/Lenovo-ThinkPad-Lithium-Battery-0A36303/dp/B0085MPGDG?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o04_s00

This is a legit lenovo battery, I have been using it for months with no issue.

I also don't think this laptop can really be called an ultra book at all. It's huge, it's heavy, it's thick. It's a great laptop but it certainly doesn't belong in the same category as the macbook air or dell xps 13.