Experience with Used ThinkPads?

[OneHellaBytes]

I want/need a portable machine for an upcoming project, and because I spent a lot of money already on my gaming rig, I wanted something cheap. I found out that eBay is full of used old ThinkPads, and they seemed really fun to work with. I looked at the ThinkPad subreddit and people were really modding theirs to perfection, and while I will not initially plan on upgrading, I might eventually swap the TN panel for a FHD IPS panel.

I am planning on carrying it outside every day in a backpack, and both the T series and X series seemed to suit me well. What are the differences between the two? Most listings on eBay were the T420 ~ T450, including variants. For under $200 without upgrades, what is the best used ThinkPad?

[Hugh54321]

careful with batteries. some people sell junk batteries

[OneHellaBytes]

1 hour ago, Hugh54321 said:

careful with batteries. some people sell junk batteries

A lot of sellers (so far I've only been looking at top rated sellers) say they have no gurantee on battery life, other than that it works. Are genuine replacement batteries available from Lenovo themselves?