Vibrating when in neutral

I have a 2012 I4 4x4 single cab manual Tacoma and I noticed after taking my sound system out that the engine vibrate in neutral Not to Long ago I changed spark plugs oil filter oil and that about it just want to know if I can get sorted that vibration because beside that truck work perfectly fine when driving it just neutral

 

What engine V6 or I4?
What is the Engine RPM in Neutral?

 

How many miles on truck?

I4

 

Oooops. I'm blind...

 

Found out that my battery was low my nephew was playing music and well he just had it on not running so it was draining the battery so it had to charge up jajaja but it’s fun now and I’m bout to hit 125k

 

It good the problem no longer exists.
It’s strange that the alternator charging would make the engine vibrate.
As this isn’t normal, at least not in my experience.

Anyways, if all is normal - drive it

 

I know man I was worried for a bit of hours until it was running ok