Battery not charging after RAM update

Hello,

I got new RAM from iFixit (Two PC3-10600 8 GB RAM Chip).

Yesterday I upgraded RAM on my Macbook Pro 13 inch (Late 2011). After that, my MBP does not recognize the battery. It says "Battery not available" over the battery icon with an X. It works fine with AC conector but if I unplug it, computer turns off.

The battery was working fine before the upgrade. I even tried the battery on another MBP and it works fine (only does not work on my MBP).

There is no problem with RAM either. On "About my Macbook Pro" it appears the new RAM, it is compatible with my MBP.

I have tried a lot of times most of ifixit solutions with no luck.... reset SMC and PRAM.

I also tried to use my old RAM but nothing changed on my battery status.

Nothing helped me.

On the App Store everything is updated.

Is there a software update or anything available for this problem?

Macbook Pro 13 inch (Late 2011)

OS X 10.8.5 Mountain Lion

Nombre del modelo: MacBook Pro

Identificador del modelo: MacBookPro8,1

Nombre del procesador: Intel Core i5

Velocidad del procesador: 2,4 GHz

Cantidad de procesadores: 1

Cantidad total de núcleos: 2

Caché de nivel 2 (por núcleo): 256 KB

Caché de nivel 3: 3 MB

Memoria: 16 GB

Versión de la ROM de arranque: MBP81.0047.B27

Versión SMC (sistema): 1.68f99