Odd sound from EOS 7D

[Geezer6951]

I have an EOS 7D that is well used. Recently purchased a 150-600mm lens (not a Canon). White out practicing with the lens, the camera started occasionally making an odd, mid-tone whining sound that seemed to be coming from from the battery compartment area of the camera body.
Put the lens on my brothers somewhat less well used 7D and the same thing happened.
The sound is not constant and happens (so far) seemingly random.
Has anyone else ever experienced this issue and if so is it something we should be concerned with?
Thank you in advance for any answers y'all can provide

[rs-eos]

How old is the battery? What brand?  If you have a second battery, perhaps use that for a while and see if the sound continues.

[Waddizzle]

Make sure the battery is not overheating.  The problem seems like a bad lens. 

[Geezer6951]

The lens works really well but we have not eliminated it as the source of the noise since it did it on two different camera bodies. Have ordered a new battery but have not yet received it 

[rs-eos]

If that particular lens is leading to that noise/sound on two different camera bodies, then the lens is probably the issue as Waddizzle mentioned earlier.

[Geezer6951]

Yeah that's what we're thinking.