I have a Moto DROID (v1). On a trip from Tyler, TX to DFW airport I had my phone in the car dock and charging. I was using Navigation for directions to the airport and also had Listen running to play a podcast over the device speaker. As I neared the airport, the phone rebooted a few times and then remained off. I took the phone out of the dock and noticed it was very hot to the touch. At the airport, the phone had cooled and I plugged it into a wall charger. The battery was completely drained!

My brother had the same experience with his Moto DROID (v2). He was on a 4 hour road trip and was using the navigation app and participating in a conference call (hands-free). The phone was connected to the car dock and charging the entire time, but after a couple of hours the phone rebooted and then shut-off with a dead battery. We left the phone off and plugged into the charger for a while and it was able to boot again, and like with mine showed a dead battery!

Is the phone really able to drain the battery faster than it can be charged via the car dock? If so, are there known combinations of apps or uses that will cause this behavior?

  • 5
    I think we can use your two examples as known combinations of apps that will cause this behavior. :-)
    – Matt Casto
    Commented Sep 15, 2010 at 19:55
  • Navigation is the one common between the two examples. I'm trying to learn if it is some combination of components (GPSr + BlueTooth? GPSr + Speaker? GPSr + Anything?) that causes the phone to drain faster than it charges.
    – JadeMason
    Commented Sep 15, 2010 at 20:21

4 Answers 4


I think you answered your own question ;)

Navigation uses a lot of power: it needs constant use of GPS along with reading the map and processing text to speech. Throw in another power-intensive activity like bluetooth or the phone's speaker (or calling, or data, etc), and it's very conceivable that it would drain power faster than it can pull it from a charger, especially a car charger, though the exact specifics would vary from phone to phone.

Here is a great list of the things that use the most power on a phone.

  • 2
    Thanks for that list. It boggles my mind that 1) when on the charger it still powers from battery rather than bypassing to the external source and 2) it can drain the battery faster than a charge.
    – JadeMason
    Commented Sep 16, 2010 at 14:19
  • @JadeMason: I mean, when it might need more power than the charger can provide, what else can it do but use the battery...
    – user541686
    Commented Apr 28, 2019 at 10:06

Make sure the charger outputs 1 amp. Most vehicle chargers that aren't specifically for smartphones or don't list output are going to be .5 amp.

  • 1
    In both cases we were using the Motorola car kit adapter. I haven't put a meter on the adapter, but since it came from the manufacturer of the phone and is intended for use with the phone, my assumption is that it is at the proper amperage.
    – JadeMason
    Commented Oct 14, 2010 at 13:19

This might just be a nonsense story but here is a start.

Some 'chargers' don't supply enough power to fully and quickly charge the device. A car charger might just not give enough power to charge faster then the applications are using the battery.

Ever noticed a computer cable charging slower then a wall socket charger. There is a difference there.


You can always underclock the phone, I notice a SIGNIFICANT decrease in heat generated which means less energy used. Yes it affects performance, but may give you what you need. Running the EVO 4G (so I can underclock to 50% and still get same mhz as the droid).

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .