Cell Phone to Start My Prius - true story

must be nice. i tried that. did not work. your battery was low, not dead.

i had to crawl into the back hatch, open it with the manual release and connect direct to battery.

the hood option would not allow the battery clips to stay on and i had no help

 

I wrote a long reply using this argument as well but then didn't include it because given by some miracle that the current was able to flow from the cellphone to the car battery, a fully charged smartphone's battery has enough power to start up a Prius IF the cellphone battery was able to transfer all of its power to the car bettery. A high power cellphone battery such as this 4500mah extended battery has 4.5ah at 3.8v. Up stepping the voltage to 14.4v and the current rating drops to just a little over 1ah. Charging a dead prius at just a little over 1a for an hour will have enough juice to provide 30 amps for 5 seconds it needs to start up the Prius. I didn't include this argument because this is not possible because the phone itself will not allow power to flow out of the charge port and the unmodified charger itself will not allow up stepping 3.8v to 14.4v. You can't take the cellphone and its charger out of the equation because as OP stated, he used his cellphone and a charger to start his car.

However, If you were to build a DC to DC converter using cellphone charger parts and using a cellphone battery as source of power and take the cellphone itself out of the equation, then YES a cellphone battery, not the cellphone, can charge up a dead prius's battery and start it up.

 

The OP stated, simply, that he plugged his cell phone into the 12V aux port and his car started. This is horse manure. He didn't mention of modifying the cell phone or charger in any way. We all know that an OEM cell phone and charger will not back-feed the 12V aux port to charge the Prius battery and start the car.

Yes, a cell phone battery with a DC-DC converter will produce way more than enough voltage. Look at the disposable cameras from years ago (may still have them today). They have something like a 9V battery produce ~300 volts for the flash. Look at stun guns. They have something like 3V batteries produce ~20,000 or more volts. The problem is the current needed. Not sure it can get that done.

Can it be done, yes. Was the OP's cell phone the reason for "charging" his Prius and getting it running? No. Period.

 

My point exactly but some people swore up and down that it is possible.

 

OK I read this whole thread. The OP and all the posters who say they have experienced this have a Gen 1. Nobody else seems to have picked upon this. Does the ACC/ cig lighter power bus work different in the Gen 1? If the phone charger was a transformer type then there would be a voltage step up to 12v nominal. Some sort of minimum voltage threshold at work here to turn on the display which enables the ECU's?

My Ford's radio has a single 12v wire running to it from the ignition switch that lights the display and enables the radio. If the voltage is under 10v on this wire the radio doesn't work. I have a short somewhere pulling this voltage down and disabling my radio.

Just an Idea.

 

Almost all Japanese cars have ACC switch cig lighter. This includes the Gen 1 Prius. Almost all American cars have a constant cig lighter.

 

No. The Classic Prius is similar to other Prius in that if the car is IG-OFF, the 12V power socket will not be active.

A transformer works with AC voltage. Since we are talking about DC voltage, a transformer by itself is not going to do anything.

Typically a DC to DC converter will have the input DC powering an oscillator that produces AC voltage. That voltage goes into a transformer to produce a different AC voltage of the desired magnitude. The AC voltage is rectified, filtered and regulated to provide the desired DC output voltage.

If you apply voltage to the output terminals, nothing will happen as the DC/DC converter does not work in reverse.

 

I believe that the sequence of events described by OP is possible in any generation Prius. But don't fall for the [ame="http://en.wikipedia.org/wiki/Post_hoc_ergo_prompter_hoc"]Post hoc ergo propter hoc[/ame] fallacy. The scenario known to me doesn't care whether the item plugged into the 12V outlet is a cell phone charger, a cotton ball, or a piece of gravel. That portion of the story is an irrelevant distraction.

A standard DC-DC switch mode power supply will NOT do this.

 

The sequence reported is:

1. Battery dead with the headlights on
2. Turn off light switch
3. Plug in cell phone
4. Start car - it works!

The kicker is that #3 can be replaced with anything you want. A gift from the gods. Adding air to the tires. Anything that takes a little time.

Once the drain on the battery was removed, it recovered enough to start the car. Batteries do that.