personally I would get a lithium battery pack that can charge your phone and other devices - quite small will run a phone for a week or so also gives you a backup cellphone supply if a power cut at home.

We just did  a 10 dayn road trip.. most of that was no cell coverage
In the tent I have a pb acid jump pack.
 That has a cigarette light port.. into that goes a usb adapter.
 The main jumper go to old school trouble light fluro lamps in the tent rooms.
 It holds quite a few days power, dont know how many as never run it flat
To re charge if staying in one place I hook a elcheapo solar panel in to the cig port or to the jumper leads and turn on.
 If need to charge faster , then start the vechle and hook the cigarette ports of both together and go for a drive. 

Was real cool being away, and only times did connect up was between camp sites on a hill .. the check Gaspy for fuel prices , ans/or camp-mate for next possible camp site.


So I need to retro fit a double USB charger on the dash somewhere so that we can recharge the phone when out fishing. I want to drill a round hole then fit it flush on the dash.

Yep done that.. best way is a cigarette light port that also has a USB port..
Make sure it is a more expensive marine type..
And mount on a verical surface so moisture doesnt get in.

I have also mounted 2 cig. lighter ports in the lid of my battery box.. connect directly to the battery terminals with a 10 amp fuse.
 This is where I connect my solar charge when the boat is parked up.
 And if at any time something goes down, it gives me a 12v amp supply to quickly jerry wire  things like a bulge pump  or lights etc... or if someone has an electric reel.

MacSkipper wrote: personally I would get a lithium battery pack that can charge your phone and other devices - quite small will run a phone for a week or so also gives you a backup cellphone supply if a power cut at home. Better yet a lithium battery jump starter - bigger but not to big - will start boat can also charge devices phones laptop etc. Getting a marine grade fitting in boat will cost and you cannot charge elsewhere if camping etcand I bet it will corrode out quickly...

smudge wrote: MacSkipper wrote: personally I would get a lithium battery pack that can charge your phone and other devices - quite small will run a phone for a week or so also gives you a backup cellphone supply if a power cut at home. Better yet a lithium battery jump starter - bigger but not to big - will start boat can also charge devices phones laptop etc. Getting a marine grade fitting in boat will cost and you cannot charge elsewhere if camping etcand I bet it will corrode out quickly... I can't recommend a socket to use but this is a really good option. A PowerAll or similar would keep your devices (I hate that word) charged for ages

looks good and suitable prices have really come down, like that is dual cigarette and usb - still not convinced it would last but squirt regularly with inox keep covers closed and have in a DRY SHELTERED SPOT and you will be fine.  

I have had this one in my boat for years.
https://www.burnsco.co.nz/shop/12v-electrical/distribution/connectors/dual-usb/cigarette-socket-surface-mount

Never sprayed it with anything.
The USB leads however.....went nasty fairlyquick.

Lanocote is a marine version   of inox which is food grade. Lanocote better. I find crc/wd40 attacks some plastics.