We didn’t give much thought to iPhones overheating last summer, when reports were going around about iPhones shutting down after a certain internal heat threshold was met. But that’s because we never encountered this behavior, since we evidently didn’t put our iPhone through these types of paces. Things took a turn when we began using our iPhone 3GS as a daily GPS device.
In the car, while we’ve experienced exceptional heat emanating from our iPhone 3GS, we still haven’t witnessed the device overheating and shutting down the active program. We guess that’s because of where we mounted the iPhone; it sits right in front of a vent. During summer months on the east coast, we usually run with the air conditioner on, so the iPhone isn’t at the same temperature as the outside world. Since it sits so close to a vent, it’s also getting the benefit of air flow, which isn’t the situation in our second use case.
On a motorcycle, our iPhone is more exposed to the elements, or at least the heat. This is doubly-problematic because air flow is effectively neutralized since a motorcycle-mounted iPhone is generally enclosed for protection, so the iPhone doesn’t benefit from the motorcycle’s movement. On hot days, this means that whatever case the iPhone is in acts like a greenhouse. Eventually, east coast summers with temperatures in the 80s will shut down any iPhone mounted to a motorcycle, making navigation-by-iPhone impossible.
Moving the iPhone to an unenclosed case, snapped into some sort of mount, may be a part-time solution. Mounts like this exist, but their protection is questionable; do you really trust a mount where the iPhone “snaps in” and “snaps out” by pressing a plastic tab? With the vibrations common on motorcycles (not to mention bumps from off-road riding), it becomes a huge question as to whether such a mount won’t suddenly pop an attached iPhone off mid-ride.
A better mount system might still work here, but an off-the-shelf solution doesn’t seem to exist. Touratech makes decent aluminum mounts for other GPS devices, but not for the iPhone (probably because the iPhone isn’t water-tight).
Relocating the iPhone’s mounting location may be possible with the proper hardware. For example, if the iPhone could be mounted in a position that offers more shade, where it’s not always getting direct sun, perhaps it would last longer before shutting down. Still, this likely wouldn’t fix the problem entirely, and GPS coverage may be hit too.
Another solution may be to simply keep the iPhone in a vented pocket, so it’s not getting sun and benefits from airflow directed against the rider. Unfortunately, this means the rider only has access to audible cues, can’t see the map, and needs to pull the iPhone out whenever the navigation software needs to be accessed.
In the end, no obvious solution exists if one wants to use iPhone-based navigation year-round on a motorcycle (at least in areas where it gets hot).
The 4G iPhone.
The latest iPhone, releasing later this week, uses the A4 processor, which we know to be faster than previous iPhone processors. This new iPhone should also sport better power efficiency, which may imply cooler operation. However, we couldn’t find any claims as to how much cooler the 4G iPhone runs compared to the 3GS. For us, this becomes a major factor in whether or not we upgrade, because if this new iPhone can handle higher heat environments, then it immediately challenges other GPS units for motorcycle use; potentially, with an aluminum case, heat dissipation may be easier for this latest iPhone.
For those early adopters, drop us a line to let us know if the 4G iPhone seems to run cooler than the 3G or 3GS.
Update (06/23/2010): TiPb is proposing that [Apple may have down-clocked](http://www.tipb.com/2010/06/23/iphone-4-teardown-apple-a4-1ghz/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed: TheIphoneBlog (TiPb: iPhone, iPad, iPod)&utm_content=Google Reader) the A4 processor in the 4G iPhone in order to get better battery life and “lower the thermal impact.” This would mean that the new iPhone has more RAM than the 3GS, but a slower processor, explaining why the iPad may still be faster than the 4G iPhone. This still begs the question as to how much cooler the 4G iPhone would run than the 3GS, however.