Lenovo T420s Battery Replacement

Battery Info gleened from multiple Lenovo sites:

Lenovo System Service Parts Link shows the following FRUs:
– 42T4845
– 42T4847

Part numbers obtained from Lenovo Batteries and Battery Charger – Reference guide / compatibility list (link):

– 0A36310
– 0A36309

What I’m buying:
http://www.battdepot.com/us/model/notebook+battery/lenovo/thinkpad+t420s/lln235.aspx

Why I chose this: Price and Warranty
I don’t want a battery that dies on me in 6 weeks, and I don’t want to spend over $100 for a battery, so this is the solution.