I have tried couple of 12V charger in every truck for the last 11 years (3 Jeeps and now my T4R), and finally I have found what I was looking for. It is cheap, only $14,99, and he will charge your phone fast.

Things To take in consideration:
1- I have an iPhone 6S
2- I have the 2011 SR5 Premium
3- Stock front 12V plug is 0.2 AMP

So what Duracell 12V charger 3.1 AMP will do? Is to take between 0.1 and 0.9 stock AMP converting this to 3.1 AMP.

Today the test was with with stock charger 0.2 amp and my new 3.1 amp charger. Took my phone with 14% and plugged into the stock amp and after 30min my phone was at 19% (like always very slow). Then I plugged into the 3.1 amp and in 28min my phone was at 100% charged.

This is a great 15$ gadget that will charge your phone fast. Furthermore, you cant go wrong with Duracell.

My next test will be with my iPad Air 2 with this 3.1 amp. Ill post this soon.