This is what I was thinking of buying. I don't need the cig lighter receptacle , but the voltmeter would be handy just for an at a glance check

http://www.banggood.com/Dual-USB-Adapter-Charger-Cigarette-Lighter-Sockets-Digital-Voltmeter-p-949446.html

Alistair

> On Jul 20, 2015, at 8:45 AM, Abel Longoria <houstonphotog@GMAIL.COM> wrote:
> 
> I'd probably use a black blank plate then drill out two holes for some blue
> sea products that way they're wired up to 12v all of the time.
> 
> Having the USB sockets integrated in a 110v wall plug/plate means the usb
> ports need 110v in order to operate (even though he voltage is being
> stepped way down) so if your're off the grid and no shore power is
> available those wall plug usb ports won't work. not sure you can route a
> separate 12v power source to just those usb ports on the wall outlet or
> not. highly doubtful since they're made for home applications.
> 
> Just thinking out loud here...
> Abel.
> 
> 
> 
> 
>> On Mon, Jul 20, 2015 at 10:41 AM, Roy Nicholl <RNicholl@nbnet.nb.ca> wrote:
>> 
>> That's the third variation they make ... one receptacle and two USB
>> ports.  I've not use that one.
>> 
>>> On 20-Jul-2015, at 12:31, T Collins wrote:
>>> 
>>> I actually have one of these in my kitchen not the same model numbers,
>> but
>>> you get the idea:
>> http://www.homedepot.com/p/Leviton-Decora-15-Amp-Tamper-Resistant-Combination-Receptacle-and-USB-Charger-White-R02-T5631-00W/205730876
>>> .
>>> 
>>> HTH,
>>> Tony
>>