Quote Originally Posted by Alex
If I understand your needs correctly all you need is a double USB charger, I have installed one and it has constant power.

http://www.ebay.ie/itm/Genuine-New-Dual-USB-In-Car-Charger-Twin-Port-Mini-Griffin-Jolt-for-iPad-3-4-5-/271262780689?pt=UK_MobilePhones_MobilePhoneAccesso ries_MobilePhoneChargers&hash=item3f28858d11
Can that just be left in the cig lighter permanently?