Solar Panel On Top Of A Van

Powering Up At Camp

Solar-Powered Camping Setup: Efficient Energy Storage and Management

In this Article:

Alright, fellow adventurers, gather ’round! While some brave souls might opt for the full-on rustic experience with candles, gas lamps, and ice packs for the cooler box. Let’s be real—there’s something magical about flipping a switch and having light, a running fridge, and ice-cold drinks a few days into your camping trip. Technology has truly come a long way, and these days, harnessing the sun’s energy to power your gadgets is as easy as pie.

Sure, there are plenty of fancy products on the market designed to solve these modern camping dilemmas, but I decided to go the DIY route. I built my very own energy (or battery) box that powers our fridge, ice maker, lights, and even the blow-up mattress pump (which, let’s be honest, we hardly use). Basically, if it can run off your car’s cigarette lighter port, my box can handle it—yes, even your precious cellphone if you absolutely must stay connected.

Now, while the usual DC-to-DC chargers can keep things topped up while you’re driving, we chose to charge our setup with two solar panels. These panels are more than enough to meet our modest needs—unless, of course, the sun decides to take a vacation. On those rare cloudy days, we have to make the tough choice to skip the ice for our drinks and focus on keeping the meat fresh and the lights on. Even when it’s overcast (a bit better than rain at 30-50%) or raining, there’s still some sunlight peeking through, giving us about 10-20% efficiency from our 260W panels, which translates to 26-52W of charging. So, as long as we don’t run the power-hungry ice maker, we’re golden for the fridge and lights.

Now, you might be wondering, what kind of sorcery is packed into our power box? Well, let me take you on a tour of the components we use. We tweak and add to it as our needs evolve. Our latest addition? Another 12V cigarette socket for our trusty fridge.

The Batteries

Knowing that the sun only shines during the day, it’s obvious we need to store the excess energy created by the solar panels for use when the sun goes down. For this, we use two 280Wh Blue Nova batteries connected in parallel. Each battery can handle a continuous 20A charge and draw, with a peak of 40A for up to 30 seconds. This setup is more than enough to handle the inrush currents from the ice maker and fridge starting up simultaneously. Each battery has an internal BMS system, and while having them in parallel does increase those ratings, the manufacturer advised that due to the internal BMS, Ohm’s law about current in parallel doesn’t quite hold true (so it isn’t 20A + 20A = 40A continuous draw).

The Charge Controller

Our current charge controller is an inexpensive 12V/10 PWM controller, soon to be upgraded to a Victron SmartSolar 75/15 purely for remote cell monitoring purposes. The current unit does what we need—it charges the batteries during the day. We also use the load terminals for certain loads when we want to bypass the voltage drop cut-off board, like the fridge, which has its own battery monitor to prevent the battery from running too low (causing the BMS to switch the battery off). The rest of our loads run directly from the battery.

Voltage Cut-off Board

For all other loads on the battery (that are not driven from the load terminals of the charge controller), we run through a XH-M609 (20A version). It’s an inexpensive little circuit board and relay that cuts the load once a certain battery voltage (NOT State of Charge) is read over the terminals. You can control the cut-off voltage in increments of 0.1V and set a second value that reconnects if the battery voltage is above it. For example, I normally set my cut-off to 12.5V and then the second value to 0.3, so it will only reconnect the loads when the battery is 12.5V + 0.3V = 12.8V. It’s not as good as doing this with State Of Charge (SOC), but it gets the job done.

Protection, Protection, Protection

I run quite a few fuses in my box. First, I have a 10A fuse from the panels to the PV input of the solar charge controller. Yes, the solar charge controller has one for the PV input, but changing it is a bit cumbersome, so I use an inline blade fuse holder. Next, I have a 20A fuse between the voltage cut-off board and the 8-way blade fuse holder box. This ensures I don’t exceed a 20A total draw from loads connected to the box. Then, there’s another 10A fuse between the load port of the charge controller and the port I connect the fridge to. This way (except for inrush currents), the total amperage that can be drawn from the batteries equates to 30A. The 8-way blade fuse holder has a blade fuse for each port I can connect a device or light to. Most loads, like lights or cellphone/USB charge ports, are fairly light, so I use a 5A fuse for those ports. For the fridge and ice maker, I use a 10A blade fuse. Currently, I use 4 of the 8 fuse holders, leaving me with 4 more for future needs. For now, I just populate them with spare fuses.

Lastly, killing power to certain ports, battery, or chargers is as easy as pulling a fuse.

Current Ports on the Front of the Box

We don’t have an inverter connected to the box, as we prefer to let our hair down and enjoy the outdoor life. So, things that require AC stay at home. Most things that can be powered from the box once converted to AC can usually be powered directly from DC, like laptops, camera battery chargers, and even some minor handheld power tools, like handheld screwdrivers.

That brings us to the end of this article. If you need more information or are interested in building your own, let’s hear from you in the forum!

So, there you have it—our not-so-rustic, solar-powered camping setup. Who says you can’t have a little luxury in the great outdoors?

If you would like to give your ideas, please join the discussion in the Forum.

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