Hey everyone, found my Cayenne with a dead battery last night, threw my jumpbox on it and still can't get it to crank. With the jumpbox on I have electrical power but when I go to start and turn the ignition everything just turns off. Couldn't find anything like this described in a quick search so I figured I'd check to see if anyone had more insight before I rush off to buy a new battery. Thanks!

 

These cars take a lot of power to crank. Your jump box may not be able to provide enough amperage. They are also very finicky with their electronics. I think the best approach is to charge the battery overnight and then try again.

 

I agree, maybe the jump box itself is down on charge

 

Thanks for the input guys. Jump box had a full charge but per the dash gauge it was only able to provide about 10-11 volts at best which I'm guessing wasn't enough to crank. Managed to get the battery out to have it properly tested and it certainly seems like that's the culprit.