iPhone charger question

[w8ing4intelmacs]

This is out of curiousity, but I bought a Griffen PowerJolt recently on the cheap, and to my surprise, it worked with my iPhone 3GS in my 2002 Honda Accord. However, I tried using it in a different older car (I think it's a 1996 Dodge Caravan) and all of a sudden, I got the "accessory not made for this iPhone" message. And, of course, I put it back in my Honda and it again worked fine.

Anyway, my question is why is this? Can an accessory be car specific? Thanks.

 

[McGiord]

probably the voltage output from the 2 vehicles is not the same.
Can you measure them with a tester/multimeter?

 

[w8ing4intelmacs]

probably the voltage output from the 2 vehicles is not the same.
Can you measure them with a tester/multimeter?

haha. you're giving me too much tech savvy credit.

anyway, there's a new twist. all of a sudden, im getting the "this accessory not made for this iphone" message now. it's like after three or so weeks of working with the PowerJolt, the iphone "remembered" that it's not supposed to work with it. strange.

 

[colmaclean]

I get that message occasionally when plugging my phone into my old iPod USB cable (use it in bedroom for overnight charging).

However, if I disconnect and connect again, the message usually doesn't appear second time...

I'm guessing this surely isn't Apple trying to screw us for new add-ons?

 

[lavinci]

I agree. It's probably just the voltage that is off.