If I add a Grafoil shim when replacing my Nexus 4 battery, what are the specs for the sheet?

Anonymous August 14, 2014

I need to replace the battery in my Nexus 4, and thanks to your guide, I’m sure it won’t be much trouble.

However, I have noticed the phone gets very hot, and the comments section suggest adding a Grafoil shim to distribute the heat — which sounds like a good idea. I have two questions: 1) what’s the spec of the Grafoil sheet I need, and 2) what sort of adhesive should I use?

  1. Kannon Y
    August 15, 2014 at 1:20 pm

    The grafoil shim (it's also referred to as graphite foil) will help act as a bridge between the CPU and the metal frame of the Nexus 4. However, I would avoid using the graphite foil and instead suggest a thermal pad. You can read more details here:


    There's an industry terminology known as skin temperature. It refers to the temperature of the exterior of a device. It's the part that comes into contact with the user's skin. Metal devices get hotter than plastic ones, because metal conducts heat better than plastic. Thus, it's actually better for devices to get hot on the exterior because it means it's conduct heat better (if it's a metal case).

    I'm rambling - I suggest using a thermal pad if you attempt the mod. If mishandled, the CPU can get damaged. Thermal pads provide cushion, better protection and overall a more elegant solution than grafoil. There's also a limited amount of heat that you can transfer into the frame of the phone (because it's glass). So thermal pad isn't optimal for heat transfer, but because of the limitations of the frame, it's probably the best.