During our search, however, we also found other people getting the same error message even when they were using USB-based chargers. If this is happening to you, it might be necessary to clean your phone's dock port with a cotton swab. There are also a lot of Youtube videos guiding people through the steps necessary to replace your dock port altogether in case your warranty is up. If you still have your warranty, there seems to be many success stories of people taking their iPhones into an Apple store and being given a replacement phone.
firewire based charger. These were around primarily during the first generation iPhone which accepted the firewire chargers. Apple then changed the hardware in the iPhone itself to only accept USB-powered chargers because the current was more uniform. Knowing this, it is always good to double-check a charger you're not familiar with to be sure it has a USB end and not a firewire. We've also seen some discussion on various forums saying that leaving your iPhone plugged into these old charges could potentially damage the battery in the phone itself. We could not find a confirmation of that anywhere on Apple's site.