T420 replacement battery

[spiney]

Hi,
This is my first post to the forum. I have a Thinkpad T420, which I purchased refurbished 7 years ago and it has been a brilliant laptop. Over the years, I have upgraded to SSD and Windows 10 Pro. I rarely use the laptop on battery but recently downloaded the Lenovo Diagnostics Windows utility to do a thorough check on all the laptop's hardware. The only problem highlighted by the software was the battery, which failed the check, the error being “Your battery has a lower then expected relative capacity.” “Design capacity: 56.16 Wh (5366 mAh) Full charge capacity: 23.56 Wh (2251 mAh)” The battery was purchased 6 years ago and is showing on the system as a Sanyo and a 55+ model. I am considering purchasing a replacement battery and need some advice. If I purchased a 9 cell battery, would I need to upgrade my power brick which is a 65W version?
TIA
Norman

[RealBlackStuff]

The 90W (with round barrel plug) will definitely improve charging times (and be a bit cooler as well).

[MikalE]

Lenovo needs to start proof reading their error messages before releasing them for distribution.

[dr_st]

Lenovo needs to start proof reading their error messages before releasing them for distribution.

No, you don't understand.

First it's lower.

Then it's expected.

Like the 5 stages of grief.