5 V power supply needed for long term journey in 4runner

Thread Starter


Joined Mar 17, 2016
I'm on week 5 of a multi-year camping trip in North America. I'm able to make this trip because I do freelance writing work from the laptop, which can be done anywhere with an internet connection, and in many cases, places without. My base of operations is a 1993 4runner, and I'm running into some issues with electricity storage, generation, and transfer. Electricity generation comes from the 4runner alternator. Storage is presently just the car battery and all the batteries in the various devices I have (and depend on).

What I'm thinking is that I have so many 5V devices that I should install a dedicated ~12V DC - 5V DC converter that has nice smooth regulated output and can push 10ish amps. Here's what I'm trying to power off 5V:

- dashcam ( ~0.5-1 A )
- Samsung Galaxy S7 ( 2-2.5 A )
- old phone for music ( 1.5 A )
- Garmin vista hcx GPS ( ? maybe 1 A )
- a few misc items - goalzero light / battery, 12000 mAh ravpower battery pack

So the question is: How best do I rig up a 5 V power supply to power all of this? I've spent a few hours researching peoples' tangential approaches and haven't really figured out the best solution in my case. I need to figure out fusing from the safety/fire side as well as the protecting my devices side, I want to if possible and not prohibitively expensive install a meter that shows battery current state and how much power each device is pulling, I want to mount all of this so there's not a mess of wires everywhere, and finally I want to install a wireless charging thing for my fancy new phone (what's the point of having a fancy new phone if you can't take advantage of fancy wireless charging?).

Any imput that anyone has is much appreciated. I've been out in the cut without cell / internet signal for 10 of the past 12 days, and so internet access is temporally a valuable commodity for me. Thanks for any help you can render! I'll share some photos of the trip if anyone's interested.


Joined May 23, 2013
To avoid the chance of discharging the vehicle battery to the point where it can't crank the engine, why don't you do what caravan owners do? That is use a separate deep discharge battery and isolator/ charge control for you auxiliary power. Most caravan sellers should have them in stock and probably will have a 12volt to 5volt regulator as well. Last thing you want is to not be able to start the vehicle because you've drained the battery. word of caution, NEVER try and start the engine with the deep cycle battery as the high current demand will damage it.
Good Luck :)

P.s, why not buy a cheap solar panel for keeping the battery topped up when you are not running the engine? most car accessory shops sell them.


Joined Nov 18, 2012
Not sure which of your threads you want us to answer on so I will try this one.Good idea to get a second battery, perhaps AGM or Gel cell for many reasons (space, deep cycling, strength etc) and connect to your battery through a magnetic switch. Do not use isolation diodes because they tend to fail prematurely. Get a pure sine wave converter for your laptop, because it won't like anything that is not clean and you should be good. Samlex is good brand, there are others. Nice clean install.


Joined Oct 15, 2009
You can get things like this all over the place..
Some with more cig outlets and usb.. some all usb,etc...
Just check the current ratings to find one that works for you but a regular 12V cig outlet in your car should be able to do 12V @10A (120W) which is plenty for the 50W you want..

Its up to you to make it all "pretty" as far as the wiring goes.. Hide it in the glove box/center console or whatever..