I don't have the need for a dual battery setup in my 4Runner for several reason. For the most part I don't have high drain accessories. I also don't always travel in one vehicle or stay at the vehicle. As such I've always liked the idea of portable power to go.

I've seen some cool products from GoalZero and ArkPak but they are expensive to the point I won't buy them. Portable power isn't a must but can be a necessary part or a trip or activity. Most of our camping is off the grid and self contained but unless we're backpacking we're at the vehicle. I also volunteer with several different agencies doing a variety of tasks, some of which is emergency communications. These along with my home were reasons I wanted to build something.

I've learned a few things and now that I have one up and running I'd like to build at least one more, probably one a little larger and maybe a few smaller and more simple versions.

For the most part it's a battery charged by a solar panel through a charge controller. I'm still working on some more pictures but here is the working end of it.





Back end of it.



I've had this for a couple of weeks and in the beginning it was just wires and connections while I figured things out. One thing I figured out is that I wanted the charge controller visible and not something that had to be dug out. Lights on the controller let me know if the panel is connected, if it's in the sun, the state if the battery and if I have a load or want to turn on the load portion of the circuit.

This crudely cut out board sits in a small battery box on top of a battery. The top of the box snaps on and has little cavities for cables and wires to come in and out while the cover is on. The blank spot is for putting a phone or accessory that is charging. I wanted this system to be easy to use and build on to. As such I used a fuse block that has constant power and ground so adding is plug and play. I put AC plug ends on my solar panel so it can be plugged into the box (yellow extension cord) and if you are in the shade or in a vehicle an extension cord can be used as wiring for the panel or for powering a device. The switch on the outlet is for the panel in case the battery is topped off and I want to disconnect the panel from the circuit without unplugging anything.

There is a Blue Sea 12v socket, Blue Sea dual USB outlet rated at 2.1 amps and a 200/400 watt inverter with another USB port (2.1a). I don't have many things that run off of a 12v socket so I only installed one. I bought two so I may add it later or use it for another box. Most items that need external power to run or charge use a USB cord. I also have a little USB socket I could put in the 12v socket if the dual socket and one on the inverter aren't enough.

I chose the small inverter because of it's size (in output and dimensions) and the fact it does not have a fan. Inverter fans draw power and create noise that I wanted to stay away from. I also didn't want to draw dirt into the box if I didn't have to. The small output is plenty to run enough lights to light most of the interior of my house (6w Cree LED bulbs), run my LED flood light, charge power tools, run my modded Dewalt cordless drill, box fans or laptop. It's also sized to work with my smaller battery. I own a 400/800 watt inverter that usually stays in the 4Runner so if I need more power I can hook that straight to the battery or some terminal studs I've been thinking about installing. There is much to be said about different batteries but this is a flooded starting battery for cost and start up reasons. It's also perfect for starting the 4Runner if necessary.

During regular duty at my house, this box is plugged into a 20w solar panel I have on the roof. The panel is in the sun most of the day throughout the year. Even in the early evening when the panel is shaded it gives about 18v down from the peak of 21.9v. The inverter takes the voltage and feeds it to the battery depending on the state of charge. I've found that even with running lights and playing around with this at night I'm back to full within a few hours the next day (full sun, no clouds).

My next box might be just a panel, controller and battery in the attic to power my eave lights, just because. These lights are on from dawn to dusk year round. The controller I use is pretty cool and can be used as a timer. Since it processes power from sunlight it knows when it's dark. It's got a timer function to turn on when dark (this is actually before dark but when the power input is less than 15v) and stays on for a user chosen amount of time or until the sun comes back up. The lights are dirt cheap to run and the power has only gone out (~15 minutes) once in 6 years but it would nice to have them on uninterrupted power if there was an outage...until all the neighbors showed up.