G&G MP5 Sportline

I just got this in the mail, and I'm really confused about something. When I went to go set the hop-up, I fired maybe 500 rounds through it (3 mags or so). Once onto the third mag, I noticed that the grip was getting VERY hot. After I finished and went inside, I pulled out the battery, which was also extremely warm. Is this normal, or is there a problem with it? The battery's an 8.4v unknown mah.

Btw, hello everyone, I've been gone for a looooong time.

It is fine, that just means that you are putting your motor through extended use, same with the battery. My suggestion is to not go full out for too long because it makes your motor spin repeatedly which in turn heats it up, also the battery is hot because it is out putting so much energy for the motor to spin. It is fine if they heat up a bit, just don't go overboard with the shooting.