"Charging paused. Battery temperature too high" while connected to car charger I have a Galaxy S2 with ICS.
When I use it in my car, while it is charging from a car charger, I occasionally get this popup:
"Charging paused. Battery temperature too high"  



Also Waze is running while this happens.


Is there anything I can do to prevent this from happening?
Does this indicate that my car charger is defective?
Your charger is fine. Only your phone is running hot due to heavy usage.

Your phone has a few components that dissipate heat if heavily used:


The processor when used heavily by an app (yours has 2 cores)
The graphics chip when your app uses OpenGL (also for screen composition)
The display when lit (depending on the brightness)
The battery itself (when charged or discharged heavily)
The modem also needs rather much power for 3G/4G/LTE data transfers


If this all above leads to a high battery temperature a safety mechanism kicks in for security reasons (LiIon battery technology needs this supervision, you may have heard of burning or exploding consumer tech)

Reasons: It's mostly a mix of all things above. Maybe it's also a bad programmed app (requires too much computation, keeps CPU awake, etc.).

What you can do:


lower screen brightness
underclock your CPU via SetCPU
Is Force GPU rendering in the developer settings enabled? If so, disable.
Try another app or file a bug report for waze (maybe)
Does the app work also when the screen is off (I'm not sure what it does, maybe it has speech output that doesn't require you to look at the screen)
maybe it's due to your model (I heard the i9100G generates more heat)
Switch to 2G only in the mobile networks settings:
Settings->Wireless&amp;networks->more->Mobile networks->Use only 2G networks (saves battery)