Reddit mentions of Anker New Laptop Battery for Lenovo (IBM) ThinkPad X200 X200S X201 X201I Series - 18 Months Warranty [Li-ion 6-cell 4400mAh 49WH]

http://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles_pdf/43Y6632_09.pdf

The hardware maintenance manual for the X201. All you ever wanted to know about replacing hardware in your laptop.

I have an X200 I rescued from a trash heap that I reinvigorated with a new battery, new ssd, and 8 gb ram. It's fantastic.

The battery I used was an Anker 6-cell: http://www.amazon.com/gp/aw/d/B00AQ9RIAA?pc_redir=1395266463&robot_redir=1

The SSD is a samsung 840 120 GB: http://www.amazon.com/gp/aw/d/B00E3W15P0?vs=1

I'm looking for a replacement battery for my X200 as well. Generally, some common problems faced with 3rd party batteries are:

• Not recognised by Thinkpad software, leading to occasional messages saying that battery is not supported. More of a nuisance actually since it doesn't limit the usage of the Thinkpad.
  
• Incompatibility with Ultrabase due to different shape/size from the original battery. However, there are some that appear to be compatible and allows the Thinkpad to fit in the Ultrabase.
  
• Typically poorer battery life compared to the original.
  
  This seems to be one of the options with generally positive reviews on Amazon, doesn't cause warning messages to appear and supposedly works with the Ultrabase.
  http://www.amazon.com/Anker%C2%AE-Laptop-Battery-Lenovo-ThinkPad/dp/B00AQ9RIAA

Anker is a company that typically sells USB charging equipment, and they got into laptop battery refurbishing. I have a 6-cell X200/X201 battery from them: https://www.amazon.com/Anker-Laptop-Battery-Lenovo-ThinkPad/dp/B00AQ9RIAA/

Looks like it's no longer available, though.

I've been buying from Amazon instead of eBay latey. If there is a problem with it, Amazon takes my word and sends me another immediately.

If I were you, I'd buy this.