ELECTRICAL

Electrical, probably the most time consuming part of the entire van build. I knew very little about electrical before I started the build. Spend hours on end learning the in's and out's of how electrical systems actually work. I will do my best to summarize it for you below.

DISCLAIMER: Keep in mind that this information is only intended for study/reference. You should be making all decisions and calculations for your project based on your specific needs. Also, I am not a professional, so don't just take my word for it. Do your own research and use common sense. There’s tons of good (and bad) information out there, so use your best judgement when deciding what’s going to work best for your specific situation. If in doubt, there is nothing wrong with consulting a professional. This is not rocket science, but a system that is designed/installed improperly could potentially lead to a dangerous situation.

WIRING

Copper wires are a must if you are planning to add an electrical circuit(s) to your van. The two most common types of copper wire are solid and stranded. Stranded copper wire is the type of wire you will need to use for your van build. Why? There are also many different gauges (gauge = thickness of the wire) of stranded copper wire that you will need to choose from, so that your wiring is safe and efficiently using electricity from your battery bank. If you run too much electrical current through too small of a wire you run the risk of overheating the wire and causing a fire. If you’re running a small amount of electrical current through a large copper wire it will be safe, but it will be wasting your money and space as copper is expensive and the wires can get pretty large. For these reasons it’s important for you to understand what gauge of wire you need to best suit the various needs of your electrical circuit(s).

 

Wire gauge numbers and size run inversely meaning that the higher the number the smaller the wire. For example, an 18 gauge wire is smaller than a 16 gauge wire, and it is much smaller than a 2 gauge wire. In order to determine the size wire you need for all your outlets/appliances you will need to do a little research and find out the Volts (V), Amps (A), and Watts (W) of your appliance. Put diagram below. This will then allow you to look on the chart below to see what size wire you need.

 

For Example: Charging an iPhone ....

For this reason, it is important to know what each outlet will be used for and to adequately equip each outlet with the proper wire gauge. For example, one of my van’s outlets is located in the bed area, so that I can charge my phone when I sleep. I know I’ll never want to run my microwave off this outlet, so I knew I would be fine to supply power to the bed outlet with 16 gauge wire. Conversely, I have an outlet located just above the counter in my kitchen/prep area and I know that I will probably use appliances here with much higher power needs than that of an iPhone. For example, I may want to plug in a blender. For this reason, I went the safe route and made sure to use a gauge wire that would be capable of supplying power to something as large as a microwave or refrigerator. This way you can safely charge an iPhone, use a blender, or microwave all from the same outlet. 

AD/DC

There are two different types of electrical circuits used for common electrical appliances – AC and DC circuits. It is important to know because appliances are build for either AC or DC circuits and must be connected to them.

 

AC (Alternating Current) is the type of current used for electrical outlets (anything that is built with a plug to plug-in to an outlet)

DC (Direct Current) is the type of current used to directly power appliances that DO NOT plug into an outlet (usually anything controlled by a switch. i.e. ceiling lights, ceiling fans, A/C units, water pumps, etc.). It connects via + and - wires coming from the appliance)

Chances are that in your van you will want both DC and AC circuits and the good news is that you can do both! Lets talk about the signal flow (the electricities path from beginning to end) of each circuit so you can get a better understanding of whats happening before you start to build.

DC Circuit Signal Flow

DC is always the current is generated in your van’s solar panels, or alternator/van battery which then flows through your stranded copper wires and into your van’s battery bank. When you need electricity, (usually indicated by flipping a switch) it will flow from your battery bank as DC current to the positive side of your fuse box, through the fuse, and out a wire to your DC appliance to give it power. The electricity then flows back out of the appliances negative, through the copper wire, to the negative side of your fuse box and then to Ground. Diagram below.

 

Those batteries store electricity that will flow out of them as DC current. The reason the switch is used in a DC circuit is so that you can turn off the appliance. Without the switch the appliance would always be on. The switch allows you to break or create the circuit for the electricity to flow and the appliance to work.

AC Circuit Signal Flow

Just as with your DC current, the electricity is generated through your solar panels, or alternator/van battery as DC current, into your vans battery bank. The electricity then flows as DC out of the battery bank into an Inverter, which INVERTS (crazy I know) the DC current into AC current. That AC current then runs through the stranded copper wire to your breaker box. From your breaker box it goes through the breaker, out to the outlet, into the appliance’s plug (which is plugged into the outlet), into the appliance, makes the appliance work, and then out of the appliance back to the outlet, from the outlet back to the breaker box via the - wire and then from the breaker box to ground.

 

Fuse Box & Breaker Box

 

The Fuse Box and Breaker Box protect your appliances from breaking and against a potential fire in the event of a circuit overload, short circuit, or ground fault. They do this by either blowing a fuse, or tripping a breaker, which inhibits electricity to flow throughout the circuit in the event that it becomes a hazard.

 

Example: Let’s say you have a microwave (which plugs into an outlet, so it is AC) that is a 120 Volt appliance that runs on 50 Amps. The breaker that the microwave outlet is connected to will be rated for, 65 Amps. This allows for a slight fluctuation in amperage usage because a 120V 50A microwave will use slightly more, and slightly less Amps than what it’s rated for. A 65A breaker, rather than a 50A breaker, will flip only when the microwave is demanding an unsafe amount of electrical power. If for some reason the microwave outlet pulls more than the 65 Amps it could overexert that circuit. The gauge of wire used to power this outlet is only supposed to support a 50A microwave at 120V. If it starts pulling 80 Amps, for example, it would probably over-heat the wire and it could start a fire. That wouldn’t be good! Luckily however, the breaker is rated to 65 Amps, so before any damage is done the breaker will flip at the 65 Amp threshold and break the circuit, stopping anymore flow of electricity and stopping any potential danger or fire.

 

Fuse Boxes work the same way but instead of a breaker flipping the fuse will blow. When a fuse blows it protects your circuit and the appliance just like a breaker does, but you can’t flip a fuse back like you can a circuit breaker. If a fuse blows, you must replace it with a new fuse. Luckily, fuses are pretty cheap. You can get more for anywhere between $3-$10 (maybe even cheaper – Look online!).

BATTERY BANK

Your battery bank is comprised of one or more batteries. Depending on your electrical needs you may want one or more batteries, and you may want batteries that have bigger or smaller capacities. The more batteries you have, the more money and space it will cost you. Likewise, the larger your battery’s capacity (AH or Amp Hours) the more money and space it will also cost you


Your battery’s capacity is how much electrical power (Watts/W) it can store. This is measured in Volts (V) and Amps (A). It is important to understand how we evaluate electrical power, or Watts. Electrical power, or watts, is measured by multiplying Volts x Amps (Watts = Volts x Amps).

 

EXAMPLE: An easy way to understand this is to use a flowing river as an example. If you want to understand how powerful a river is you need to understand how much water is flowing in the river (Amps), and how fast that water is flowing (Volts). If a river has 100 gallons of water that flows by every hour, that river would be said to be flowing at a rate of 100 gallons per hour. Electricity is similar where we multiply Volts x Amps to get the power of the electricity (Watts).

 

Batteries are rated in different power (W) capacities, which as stated above, is determined in Volts (V) and Amps (A). However, because we use batteries to supply us with power over an extended period of time, it is important for us to have an idea of how long a battery can supply us with “X” amount of amperage at a given voltage. For that reason, batteries are rated in Volts and Amp Hours (ah). This tells us how many amps every hour a batter can deliver at a set voltage. For example, a 12V 100ah battery could deliver 100 amps at 12 volts for an hour before it would be fully depleted.

 

Okay, so hopefully you’re able to follow along, but if not let’s do a quick review.

Electrical power = wattage.

Watts = Volts x Amps (W=VxA).

Batteries can deliver a certain number of amps at a certain voltage for a certain length of time.

We rate batteries in Volts and Amp Hours (i.e. 12V 100 amp hour battery, 24V 100 amp hour battery, 12V 200 amp hour battery, 24V 200 amp hour battery). 

 

EXAMPLE: If I plug my iPhone in to charge and it charges for an hour at 12V consuming 5A then my phone is consuming 5ah (amp hours) at 12V. But what if you only charge your phone for 30 minutes at 12V consuming 5A? Well then, you’d only be charging your phone for half of an hour which means your phone would be consuming 5ah divided by 2. This means your phone would have consumed electricity at the rate of 2.5AH (5AH ÷ 2 = 2.5AH). We divide by 2 because we didn’t charge the phone for a full hour, instead we used it for exactly half of an hour (30min), which means we divide 5 Amp Hours by 2, which leaves us with 2.5ah.

 

The importance and method of choosing the right battery for you

INVERTER

The inverter is important for your AC circuit because it will allow you to get the DC current to a usable AC current for your AC appliances. Inverters are only able to output a given amount of power (Watts/W), so make sure your inverter is rated to provide enough power (Watts/W) for your needs. For example, you can buy a 2000W inverter, but if you need to pull more than 2000 Watts of power for any appliance that you may plug into your outlets that run off AC circuit, that 2000W inverter won’t suffice. You’ll need to make sure to buy a more capable inverter, such as a 3000W inverter. It is important to note that you, more often than not, will not be using enough power to demand your inverter to supply it maximum amount of power. For example, if I have a microwave, electric water heater, and also want to charge my computer I need to make sure my inverter can supply enough electricity to my AC circuit to sufficiently power all those appliances at one time. In most cases, however, I will not be running all those appliances at once, so I would not need to push my inverter to it’s limits frequently.

SOLAR

Solar is an amazing way to supply your van, and van’s battery bank, with power. It’s free energy baby! Thank you Sun. The main components in a solar system are the solar panels, the charge controller, and obviously the wires that allow for the transfer of that electrical energy.

 

Let’s talk signal flow again. The Solar panels on your van soak up the sun’s rays. That in turn creates electrical power that will flow to your charge controller and then to your van’s battery to charge it up! ​​​
 

The expensive part of having solar are the batteries in your battery bank, and the charge controller. The Solar Charge Controller safely regulates the appropriate charging of your batteries in your van’s battery bank from the solar panel its receiving.

 

Solar panels themselves are not very costly. If I wanted to add another 12V 100W solar panel to the roof of my van it would only cost me about $100. Solar panels are sold in different physical sizes, power sizes, and material makeup. Meaning that you can buy small, or large solar panels, panels that supply small or large amounts of power, and panels that are made of different materials. There are materials that make the solar panels more efficient (also more expensive), there are materials that make the solar panels more compact (also more expensive), and there are materials that make the solar panels more flexible versus ridged (less expensive, but tend to have a much lower lifespan than the ridged panels).  For van builds the most common solar panels are 12V 100W panels, 12V 160W panels, and 12V 175W panels. Depending on your power needs you may need just one panel, or several panels all connected to supply you with more electricity. If you are planning to only run a few ceiling lights then a single 12V 100W, 12V 160W, or 12V 175W panel (depending on how many lights and how long you plan to use them) would suffice. However, if you’re like me, and looking to run a microwave, water heater, charge your phone and computer, etc. you will want to have more power supply from your panels. To determine what panel and how many panels you should buy will require you to do some simple planning and math, which we will cover more in depth here.

 

Talk about the pros and cons of material makeup (Monocrystalline vs. Polycrstalline, Flexibly vs. Ridged) 

CHARGE CONTROLLERS

Charge Controllers are extremely important in your van’s electrical system. Their job is to monitor the charging of your battery/batteries in your battery bank and maintain that the charging is done in a safe and healthy manner for your battery/batteries. There are several different types of batteries so depending on the type of battery you have it will need to be charged differently, (which your charge controller will monitor?). Also, as they are charging they need to be supplied with more or less amperage to healthily charge your specific battery to maximize the lifespan and overall integrity of your given battery. In Layman’s terms, charge controllers are important!

Below is an explanation of different types of charge controllers. 

DC-DC Charge Controllers

DC-DC charge controllers are used to charge your battery bank from your van’s battery/alternator. They take DC current from your van’s battery/alternator and regulate how much is allowed to pass through to safely and healthily charge your van’s battery bank. 

Solar Charge Controllers

There are two types of solar charge controllers and they are Pulse Width Modulation (PWM) and Maximum Power Point Tracking (MPPT). Both of these solar charge controllers are widely used in the solar world, and have similar lifespans, while also protecting your batteries.

  • PWM

    • PWM charge controllers are great because, as they perform the same function as their MPPT counterparts, they are cheaper and more affordable. 

  • MPPT

    • MPPT charge controllers are more expensive than PWM controllers and this is because they are the newest technology in the charge controller world. This new technology allows the MPPT to be much more efficient than the PWM controller in terms of electricity. This is important because the less amount of electricity the charge controller takes, the more electricity can be stored in your battery bank. If it were up to me, I’d pay the extra money for the MPPT charge controller, but that’s just me!

DC-DC/MPPT Charge Controller

If you’re looking to charge your battery bank from both your van’s battery/alternator as well as from solar panels then this is a great option. Renogy is one of the top companies in the solar world, and for good reason – they have many great products! As far as I’m aware, Renogy is the only company with a DC-DC/MPPT Charge Controller option. Without this product if you were looking to charge your battery bank from both battery/alternator as well as solar panels you would need two charge controllers. You’d need a DC-DC Charge Controller for the electricity generated from your Van’s battery and you’d need either a PWM, or MPPT charge controller for the electricity generated from your solar panels. Purchasing two charge controllers is expensive, consumes a decent amount of space, and takes more time to set up. This is where the DC-DC/MPPT charge controller is a savior. It will take electricity generated from both your solar panels and van’s battery and use it to safely charge your battery bank. Another great feature to this product is that if your battery bank if fully charged, and your solar panels are still generating electricity from sunlight, it will begin to charge your van’s starter battery/alternator. You’ll never have a dead battery! Woooooo!!

BATTERY MONITOR

Battery monitors are an important piece of your electrical system because they will monitor the overall health of your battery and let you know how much battery capacity you have left. This way you can monitor your daily usage to gain an understanding of whether or not your consumption of electricity is too much for your current system. You never want to deal with not having enough power in your battery bank to support your electrical needs. Also, and more importantly, most batteries aren’t meant to be fully depleted of a charge. If you do fully deplete a battery of it’s charge, and it isn’t built to do so, you run the risk of significantly decreasing the lifespan of your battery bank, and/or ruining the battery bank entirely. Even the cheapest of batteries are EXPENSIVE, so this is definitely not something you want to do. For these reasons battery monitors are very important. Luckily, there are plenty of great options for battery monitors. They tend to be a bit pricey, but, when you consider the amount of money they can save you in the long run, they are well worth it. Most battery monitors work via a shunt that calculates the difference in incoming electricity (electricity going to your battery bank from your starter battery, and/or solar panels) and outgoing electricity (electricity being used by the appliances pulling power from your battery bank). The battery monitor will calculate how much power (Watts) is being added or subtracted from your battery bank and will let you know how much battery life you have left. Let’s create an example assuming that we have a battery bank with 200ah (Amp Hours). If our solar panels are generating 10A and our starter battery is generating 20A then we are getting 30 amps to charge the battery bank (10A + 20A = 30A). At the same time, we are using our kitchen lights, which are consuming 1A, and also charging a computer, which is consuming 7A. This means we are consuming 8 amps (1A +7A = 8A). The Shunt will subtract the electricity being consumed (8A) from the incoming electricity (30A), and will determine that the battery bank is gaining 22A (30A - 8A = 22A). The shunt will then deliver all of this information (and more) to your battery monitor, which is what tell us humans how much electricity we are using and how much battery life we have left in our battery bank.

DIAGRAM

Details of the different types of wires.

Your battery bank stores electricity for your use in the van. Let’s say you turn on your ceiling light. Well, that ceiling light is probably connected to the electricity via it’s + and - cables, meaning that it will be connected to your DC circuit. Everything in your van that runs on your DC circuit should be connected (and protected) to your Fuse Box. Within the Fuse Box and Breaker Box is a long, dense, metal bar that enables the fuse box to conduct as much, or as little, electricity as needed to supply sufficient electrical power to one, or more, of your DC electrical appliances. The incoming + wire (the wire running from the battery to the fuse box) will be connected at the fuse box’s (it is the same for a breaker box) + terminal. From here, all wires that will supply power to your various DC appliances will also get connected to their respective terminals. You can buy a fuse box/breaker box with only a few terminals, or you can buy them with many terminals. If your only DC appliance was a set of ceiling lights you would only need 1 terminal for your fuse box. Likewise, if you only wanted 1 electrical outlet in your van you would only need 1 terminal in your breaker box. However, in most cases, you’ll have multiple DC appliances that will need to be connected to your Fuse Box (Living room lights, bed lights, kitchen lights, water pump, drain valve, etc.) In this case you need to make sure you have ample room to allow all your DC appliances to connect to your fuse box to adequately protect your electrical circuits, your van, and the appliance itself. You may want to leave room for a few unused fuse terminals as well, in the event that you want to add more DC appliances to your van in the future. The breaker box works in the same way, but instead, you provide AC current to outlets that will then provide the electrical power needed when you decide to plug in your AC appliance. That appliance will work and run off the power supplied to it from the breaker box. As mentioned before, choosing the right gauge wire is very important for both DC and AC circuits. The more amps a wire needs to carry the larger the wire will need to be. Remember, wire gauge numbers and size run inversely meaning that the higher the number the smaller the wire. For example, an 18 gauge wire is smaller than a 16 gauge wire, and it is much smaller than a 2 gauge wire. When you run wires from your fuse box to your DC appliances it is pretty straight forward what gauge wire to use. Usually, by looking in the appliance’s manual, or by doing a little research online, you can figure out the Volts (V), Amps (A), and Watts (W) of your appliance. If your DC appliance runs at 12V, 1A, 12W then you will want to use a gauge wire that will safely carry 1A at 12V. In an AC circuit this takes slightly more effort and thought. This is because in an AC circuit you aren’t directly powering an appliance. Instead, you are running power to an electrical outlet that will then provide power to an AC appliance. Charging an iPhone for example would take much less power than a microwave. If you were to run a 16 gauge wire from your breaker box to an outlet where you were going to charge your phone as well as run a microwave, well that wouldn’t work so well. The 16 gauge wire would be sufficient for your iPhone, but it would not work for the microwave. The amount of power running through the wire to supply power to the microwave would melt the 16 gauge wire and could possibly start a fire. For this reason, it is important to know what each outlet will be used for and to adequately equip each outlet with the proper wire gauge. For example, one of my van’s outlets is located in the bed area, so that I can charge my phone when I sleep. I know I’ll never want to run my microwave off this outlet, so I knew I would be fine to supply power to the bed outlet with 16 gauge wire. Conversely, I have an outlet located just above the counter in my kitchen/prep area and I know that I will probably use appliances here with much higher power needs than that of an iPhone. For example, I may want to plug in a blender. For this reason, I went the safe route and made sure to use a gauge wire that would be capable of supplying power to something as large as a microwave or refrigerator. This way you can safely charge an iPhone, use a blender, or microwave all from the same outlet. It is important to remember that a larger gauge wire than what is needed will not cause any safety issue. For example, if you chose to use 2 gauge wires to supply power to all your outlets I would never foresee a problem in overexerting those 2 gauge wires and running the risk for a fire. However, 2 gauge wires are much more expensive that 16 gauge wires (and much larger) so just because you can do it, doesn’t mean it’s wise to do so.