Now it is to be no longer a problem 8-10h run the Navi without going to the phone the juice out: o)
Furthermore, I had a very friendly and courteous contact with the seller
I can only recommend this battery pack and the dealer !!
MFG XTPower MP-5000 power bank mobile battery with 5000mAh - 2 USB outputs for mobile phone, iPhone, iPod, iPad, PDA, MP3 player - with 10 adapters