Which Ultrabay Slim batteries fit which ThinkPads?

[bakery2k]

ThinkWiki describes four different batteries which will fit in an Ultrabay Slim: "Ultrabay Slim Battery" and "Advanced Ultrabay Battery" (I), II & III. Elsewhere, I have also seen Ultrabay batteries labelled simply "42" and "43".

What are the differences between these batteries?

Will all of the above batteries work in all ThinkPads which have an Ultrabay Slim/Enhanced or a Serial Ultrabay Slim/Enhanced, or do certain batteries only work in certain laptops?

[dr_st]

The battery connector was changed between T4x and T6x generation, so the batteries are incompatible.

The original Ultrabay Slim Battery works in all the laptops mentioned in the Thinkwiki page.

The Advanced Ultrabay Battery was later rebranded as Thinkpad Battery 42. It works in the machines mentioned here plus the T420s series. Note that as it says - the battery has been discontinued.

The Thinkpad Battery 43 is the newer revision of the Battery 42. It is the same except has the chip that makes it work in T430s, and is fully backwards compatible. It works with all the systems listed in the Lenovo reference page.

[bakery2k]

That's very helpful, thank you. So, if I understand correctly:

• The Ultrabay Slim Battery has an older battery connector and only works in T4x, R5x and the X4 UltraBase.
• The other Ultrabay batteries are interchangeable. All of them will work in all of the machines on the Battery 43 reference page, except that only ThinkPad Battery 43 has the chip required for the T430s.
• There are machines with a [Serial] Ultrabay Slim/Enhanced which do not accept any of the Ultrabay batteries - including the T410, T420 and X200 UltraBase.

Finally, it seems that Ultrabay batteries are no longer available for purchase directly from Lenovo. There are some available on eBay, which claim to be brand new and genuine...

[dr_st]

Yes, your understanding is correct. I can add T430 and Ultrabase Series 3 as examples of systems with an Ultrabay that do not accept the Ultrabay Battery.

I don't know whether/if it is still possible to order the battery from Lenovo new. You can try their phone sales department or one of their repair service providers that sell parts. I don't think it's a particular advantage to buy one new. I'd rather buy a used genuine one for one quarter the price.