car
Installing an Inverter Into your Vehicle
GUIDE TO VEHICULAR INVERTERS
So we don’t pay that damned mechanic.
P.S. There is a video series showing some of the steps. Part 1 can be found here:
http://youtube.com/watch?v=zJAI0O1gt3k
Additional parts can be found by going to the user's profile and searching for the next part.
P.P.S. I could use some money…
1. Introduction
2. Power Use
2a. Perspective: Supply Limits
2b. Perspective: Demand Amounts
2c. Understanding Electrical Terminology
2d. Basics: Calculating Your At-Inverter Power Demand
3. Our Electrical Circuit Components
3a. Alternators and Available Power
3b. Batteries
3c. Inverters
3d. Wires
3e. Power Drain Prevention
3f. Safety Components
4. Basics of Assembly
4a. Terminals
4b. Soldering
4c. Insulation
4d.
Other Tips
5. Equipment Configuration Suggestions
5a. Lighter Socket Wiring: On and Off Sockets.
5b.
5b1. On/Off with Accessories Switch on Vehicle
5b2. Independent of Accessories Switch
5b3. Potentially Independent of Switch
1. INTRODUCTION
So. You want home-like power outlets in your car. You want to have AC-based electronics with you in your vehicle. This guide is designed to teach you what you need to know to complete your project.
Installing traditional outlet power into your vehicle necessitates knowing about electrical terminology, certain circuits, putting together cabling, and more. It can be difficult to find a lot of this information, so I’ve tried to put it all in one place for you.
In case you already know a little bit about electricity, I’d like to save you the time it takes to surf through this document and tell you that if you’re running less than about 120 watts, you’re going to need a little something called an ‘inverter’. You’ll have to make sure that it has a plug for your vehicle’s lighter slot. You’ll then have to consider whether to get modified square wave or pure sine wave electrical output, which can be an important financial consideration. If you want the versatility to power certain items, and have the budget, get a pure sine wave inverter. Otherwise you’ll be stuck with device-fatiguing, low-quality electricity. Regarding those of you who’ve thought ahead and wish for the easier fix who want more than 120 watts out of the lighter outlet and are thinking about simply replacing your lighter fuse with something larger: hold your horses, as the circuitry may not be able to handle it. I oblige you to determine if your vehicle’s circuitry can safely handle it.
And now for the rest of you who either don’t know about electricity or want a setup that draws more power, is not obtrusive, or looks a little less ugly than having something sticking out of your center console: this may be the guide you’ve been looking for.
To plan for your vehicular power project, you’ve firstly got to decide what you’ll be wanting to be power. Drills, computers, televisions, high powered spotlights, pain rays, cell phones, audio amplifiers…vibrators…
After you’re satisfied with knowing what you’d like your vehicle to power, you’ve got to figure out if you can actually power it. You’re going to need to know how much power your vehicle can create and how much power your devices use. After figuring these things out, you can approximate whether your setup can actually work. I’ll now guide you in detail on each of these steps.
2. POWER USE
2A. PERSPECTIVE: SUPPLY LIMITS
Before we calculate your desired power usage, I’d like to give you a little perspective on how much power you may have available. If you’re driving at speed, you’ll probably be able to maximally use between 400 Watts and 9 Kilowatts. If idling, divide that number by four. We’ll have more on these subjects later. If you want significant power for an extended period of time while the engine is off, you’re going to need to learn how to install a battery bank. This is uncommon, so it won’t be covered in this guide.
2B. PERSPECTIVE: DEMAND AMOUNTS
Okay. First I’ll give you a general idea about how much power some common devices use. After that, I’ll teach you what all the terminology means. After that, I’ll let you on your way to figuring out how much power you’re going to use. Here’s a list of common items you may wish to use with your vehicle:
Typical Appliances:
Cell phone 20 watts
Camcorder 23 watts
VCR 40 watts
Portable stereo 10-200+ watts
Laptop 20-75 watts
Desktop Computer 64-800 watts (Approx. 150 average)
Blinding spotlight: 150 watts
Non-lethal police stun gun: 26 watts (@50K volts)
Small Soldering Iron 45 watts
Sawzall 1KW-1.7KW + inductive load!
Drill: 250 watts to 2KW + Inductive load!
Microwave 600-2200 watts
Small electric stovetop: 1300 watts
RV Refrigerator: 60-150 watts (DC Power)
Blender 300
Toaster 800-1500
2C. UNDERSTANDING ELECTRICAL TERMINOLOGY
Let’s use an analogy to help you understand electrical energy terms. How’s about Dick Cheney’s famous shotgun shot to his buddy’s face. With a shotgun, you have a number of standardized size pellets propelled from a barrel at a certain speed. The multiplication of force of each pellet with the number of pellets equates to the total damage, or power, of the shot.
A higher voltage is equivalent to a higher pellet velocity. It describes the potential force of each electron as it travels through the cable. A higher amperage is a higher number of electrons traveling through the cable per second. A higher amperage is like a barrel with more pellets. And finally, a greater wattage simply means more power. It could be due to greater power from each pellet, or a greater number of pellets, or both. Greater wattage is greater damage to the face of the lawyer.
Let’s do a little practice calculation.
Now that you
understand what these terms mean and how they relate, you can infer a way to
calculate your power needs. In case you haven’t made the inference, and want to
do it, pause it now… …Volts x Amps =
Let’s say that the pellets are moving at 7.5 Volts, and there are 12 amps of them. 7.5 x 12 is 90 watts of power.
Let’s try another example. Let’s say the world is becoming highly populated by a dangerous, wild animal. Let’s call them humans. Humans are quickly willing to resort to violent behavior. Humans are also bombarded with bullshit and are often easily manipulated by this bullshit to anyone’s purpose. Together, these could be inferred to be unfavorable qualities. If we design a place which attracts a good significant lot of these endangering and easily misled people and render their genetic code unviable for continuing reproduction, we can make a slightly safer and smarter civilization. Let’s create a war based on an obviously false set of premises, and attract these people to fight in it and hopefully become deceased, irradiated, impotent, or generally unattractive. To do so, we’ll need Mass Media.
We’ll approach
the power equation differently for this problem. I’ll give you
3,000,000 Watts = .5 Volts x Amps
by .5. This calculation yields an atmospherically blackening 6 million Amps of bullshit!
Now we’ll do a simpler example. Let’s say your vehicle’s roof-mounted laser uses 900 Watts of power, but uses only 8.18 Amps of current. What is the voltage that this device uses? Since W = A x V, and our numbers are 300W = 8.18A x (Variable)Volts, we can divide both values by 8.18 and isolate the variable Voltage, and discover that this unit runs off of approximately 110 Volt power.
2D. BASICS: CALCULATING YOUR AT-INVERTER POWER DEMANDS
So you’ve got to
figure out how many watts your item uses. Sometimes wattage is listed on your
item, and sometimes Amperage and Voltage are listed. The amperage will often be
a number followed by a capital A, and the Voltage will often be a number
followed by a capital V. If it’s a device without a power adapter, then it may
not list voltage, and you can probably assume that it’s 110 or 220, depending
on standards in your area. If voltage listed is something other than 110 or
220, then your item is probably using a voltage converter to make the current
in your house compatible with your device. This voltage converter is not
perfectly efficient, and its output in watts will be less than its input. So to
calculate how much it will draw from your inverter, you might just add 25% to
its listed output power by multiplying by 1.25. If you still can’t find the
power requirements, then you can probably find it on the Internet. And finally,
if you absolutely cannot find the power consumption of the unit, and must figure it out, you can purchase and
use what’s called a wattmeter.
3. OUR ELECTRICAL CIRCUIT COMPONENTS
Now we’re going to go into detail and we’ll figure out if you can actually meet your power needs.
First I’ll
address people who are going to be using their items while the engine is on. The
device most responsible for determining your on-the-road power consumption limits
is probably what is called an Alternator here in the
3A. ALTERNATORS AND AVAILABLE POWER
Unless you’re using a hybrid or electric car, your vehicle probably makes its electricity with an Alternator. Alternators come with differing electricity generating capabilities. The 1984 model of my car has a 12 volt, 60 ampere inverter. So does my 1988 model. Nowadays, modern cars are coming with 70 to 150 Amp capabilities, typically at 12 Volts. Monstrosities like stretch Humvee limos and sub-urbans can produce even more amps. Really old cars with fewer electrical needs will have less. For example, a 1965 VW Beetle alternator might generate 45 amps. Some alternators will be as little as 30. These ampere ratings are maximum values. The alternator spins in relationship to the crankshaft of the engine, not the speed of the wheels. They are geared with the crankshaft such that near-maximum electrical values will be able to occur if you’re simply moving on down the street. However, an idling engine and alternator might produce one quarter its rated electrical power. My little Honda will struggle to power my high beams when idling; it might be generating only 15 amps. Here is a graph showing potential alternator output for perspective:
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[This image was extracted from batteryfaq.org]
Almost all vehicles these days run off of twelve volt power, but really old vehicles might use six volt power, and other vehicles, like many diesels, can have twenty four volt systems or more. Ideally, it will be more efficient to use higher voltages for vehicles in the years to follow this instructional.
Your car uses some of this energy to fire its spark plugs and do all of its little electrical things. The more modern your car, the more electricity it’ll usually use for its information age devices. Electricity is constantly converted into heat and a loss of electricity occurs there, too. The smaller your wiring is, the more corrosion on your wires, and the longer the wire runs you have, the more electricity is lost to warming the air. Basically, not all of your alternator’s power is going to be available to run your special setup.
I’m having difficulty finding out how much electricity is used by the basic features of vehicles, so I really can’t tell you how much of your alternator’s power they use. I imagine, though, that idling wattage + lowbeam wattage (100 watts in my case) would be less than alternator generated idling wattage. So for my car, I’m imagining that 100 watts + Idle watts is less than 180 watts.
Another complication exists, and it is that most alternators were not designed to run at their rated capacity for extended periods of time and will typically die out much more quickly if pushed to do so. You might do research on your particular alternator to see if it can handle all that you wish to throw at it. Otherwise, you might just expect that it’ll handle a constant amperage about two thirds of its rated capacity for a longer life.
You can find out how much power your alternator generates by looking closely enough at it and looking for writing on it concerning its electrical characteristics, or by going online and looking for an alternator designed for your vehicle and labeled as “OEM replacement” and finding its rated capacity.
Also, importantly, you can upgrade. You can either upgrade your current alternator or install multiple alternators. For my little car, there are alternators available which pump out 200 amps. The cost of this purchase comes in many forms: The initial monetary purchase, the decrease in horsepower when they’re in use, a drop in fuel economy and range, and an increase in vehicle weight. Alternators designed for larger vehicles may have even greater potential generating capacities.
3B. BATTERIES
You’re probably
going to want to power your devices sometimes with only your car battery, so
let me give you a little perspective about how to do it safely.
For your crowd control pain ray, you’re going to need a lot of stored energy and maximum current, and you’ll need to do some independent research about setting up a battery bank to replace or supplement your vehicle’s battery. If you’re just powering a computer for a bit, you should be okay with your car battery.
Now, the capacity of your battery is rated in amp-hours. An amp-hour (an important characteristic of your battery) would be more practically presented as a watt hour for our application, but it’s not, so we’re going to have to do a bit of math. Your battery’s amp-hour rating is a measure of the total Amperes that can be drawn from your battery evenly over 20 hours before the battery drops to a voltage of 10.5. So we’re going to have to do some conversion into 12 volt amp-hours to figure out how many hours you can run your watt eating appliances. Then you’ll have to determine the charge level of your battery, the current charge capacity of your battery, and the speed of withdrawal when calculating how much energy you’ll actually have available.
Modern 2008 Lead Acid battery charge capacity is significantly changed by how deteriorated the battery has become and the current temperature of the battery. The speed of withdrawal depends on the devices that you’re driving, and the working efficiency of the electrical path from your battery to your device.
To perform a simple calculation to determine the time available on your freshly charged car battery during warm or hot temperatures, figure out how many “amp-hours” your battery has, divide by the number of 12 volt amps that your devices will draw, and divide that figure by eight. This can tell us how long your device might run off of the battery at a moderate power draw rate and ambient temperature while keeping the battery in decent car-starting condition. It is not good for your battery to be left in this undercharged state, though.
To really know
how much power you have available in your battery, you’re going to have to
learn about normal capacity degradation, the effect of rate of discharge on the
battery’s effective capacity, the effect of temperature on your battery’s
capacity, and battery charging rates. To be able to determine whether your
battery is charged, you could even do your own independent research on battery
voltage at different charge levels and the amount of time it takes to fully
charge a starting battery, but we won’t go into that detail.
Lead Acid
Starting batteries die with time. It’s a simple fact. Their deaths are greatly
accelerated by being left uncharged. Whether they’re left in an uncharged
state, or their natural loss of charge brings them to a lower charge level,
they deteriorate. Only thirty percent of car batteries in the
These batteries are significantly less efficient at greater power draw rates than their twenty hour rated capacity. A more useful figure to use when calculating power time availability is its “reserve capacity”. Reserve capacity is abbreviated RC or RCM. It is the number of minutes that the battery will pump out 25 amps of current until dropping to a zero percent charge, or 10.5 volts. If you want to get even more accurate about your actual capacity at different discharge rates, consider the information from this table.
|
Hours to Reach 100% Discharge of Capacity |
20 |
10 |
5 |
3 |
1 |
|
Percent of Rating |
100 % |
89 % |
78 % |
66 % |
45 % |
[This table is from http://www.zrd.com/blog/esdbatfrm.html.]
In addition to this battery inefficiency at quick discharge rates, it is not good for your starter type battery to drain to or be left at less than 75% charged, so if you’re wanting to take great care of your starting battery, you might really only be using a fraction of what you might hope for if you were just looking at the numbers for the first time. Divide your calculated available time by four.
Temperature has
a significant effect on the capacity of the battery. The rated capacity and
cranking amps of your battery rises and falls similarly to increases and
decreases in temperature. Please observe this graph for temperature and charge
capacity of a lead acid battery intended to propel electric vehicles.
http://www.pacificpowerbatteries.com/aboutbatts/Car%20Battery%20FAQ/carf...
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So let’s try a detailed practice
calculation for using a device. I’ll choose a laptop as the object to power.
We’re going to assume a few things. Let’s say that your connection to your
laptop is 75% efficient. Let’s say that your battery’s temperature is 3 degrees
Celsius and your battery has 80% of its rated charge capacity at that
temperature. Let’s say your battery is a starting battery rated at 50
Amp-hours, and let’s say that it is a relatively new battery which has been
treated well and so actually has its 50 Amp-hour capacity at (the industry
standard) 77 degrees Fahrenheit. Let’s say your laptop needs 50 Watts. If the
connection to your battery is only 75% efficient, then you’ll need to divide 50
Watts by .75 to figure out how much energy must be exhausted from your battery
to feed the laptop 50 Watts. It comes to 66.7 Watts of power draw. Let’s just
say that your battery is a true twelve volts for this calculation. So we’ll
divide the 66.7 actual
If you would have taken the simple method mentioned at the beginning, you would also arrive at 1.5 hours. But it is a potentially dangerous method to use.
3C: INVERTERS
So we know about batteries and alternators. Now we’ve got to change that power into outlet power. An inverter does this. An inverter is a type of electricity converter which changes DC (direct current) to AC (alternating current). There are many important features to be considered when choosing your inverter.
I’ll talk about a few of them.
The most critical characteristics are rated power handling capacity and waveform output type. Other important characteristics to consider are surge power capacity, efficiency at various loads, no-load current draw, “soft start”, peak current handling, fuse protection, physical size of unit, noise output levels, low battery shutdown and alarm, and potential for poor quality of manufacture.
There are a few reasons to have greater or less rated power capacity.:
You want greater capacity to support a maximal draw for your needs. You’ll want less capacity, though, so that you don’t have to spend as much and you can get a smaller, quieter, possibly more efficient, and lighter unit. It can be desirable to have an inverter with one and a half times the capacity as you’ll be sustaining, as at that level you’ll likely be in the inverter’s most efficient range, it’ll save your inverter from degradation and overheating, and could reduce potential cooling fan noise problems.
Waveform type is an interesting one. You’ve got True Sine Wave waveforms and Modified Square Wave waveforms. The “wave” characteristics are derived from graphs of the variance in voltage over time. Modified Square Wave is often described by advertisers as Modified Sine Wave. Just as horrible audio distortion causes mental fatigue, horrible wave forms produce electrical fatigue. Electrical fatigue means heat, noise, and possibly device damage. Using a higher quality “multi-stepped” modified square wave inverter, I fried the variable speed circuitry in my drill, blew out a line on my LCD monitor, and had many frightful noises occur in the things I plugged into them, like my computer. Fortunately, my computer still works. But it wasn’t running off that power for very long.
Here is a list of items popularly not advised to use with modified square wave electricity:
*Some cell phone chargers or other battery charging devices
*LCD computer monitors
*Some computer power supplies
*Laser printers, photocopiers, magneto-optical hard drives
*Some fluorescent lights with standard ballasts
*Power tools with variable speed or ‘solid state’ power
*Some devices with clocks could keep inaccurate time
*Some medical equipment
You can test whether some devices work by feeling their heat output and judging if it gets hot or begins to emanate scents within 15 minutes or so.
If you don’t want to spend a lot of money, and have a few devices which don’t need true sine wave electricity, you might buy a modified square wave inverter AND a pure sine wave inverter.
Surge power is nice for starting motors, microwaves, and similar devices which need massive startup current to work. Inverters with greater surge capacity are typically much heavier and are more expensive than those which don’t have great surge capacity. They also are not very common. Some devices attempt to draw three to seven times their rated power during startup.
Soft Start is a technology which limits the inrush of current. This is useful for prolonging the life of the inverter. The extreme heat caused by the startup of certain loads is enough to fry an inverter before a fuse will break or a circuit breaker will trip. If you’re powering a magnetic field like that found on a drill or something with a lot of capacitor capacity and with low input resistance, you could fry a non-soft-start inverter.
Power draw with no load can be important, depending on or your desire for increased energy economy.
Physical size is of great concern for my project, because I wish not to encroach upon the storage space or passenger movement space, and must tuck it away somewhere.
Noise output levels are of significant concern to me. I hate boring, distracting, dumbing noise. Such are the noises which typically emanate from an inverter’s active cooling system.
Actively cooled units can be noisy. Some actively cooled units might not be creating a lot of heat, but have a fan constantly going. Others might feature intelligent cooling, which controls the speed of the fan in accordance with cooling requirements. This saves you from unwanted noise.
Some lesser output units simply radiate heat into the stagnant air, and the higher wattage versions of these passively cooled devices have a tendency to overheat. They also typically feature overheating protection circuits, so they aren’t a danger to use. They just may be unreliable for long periods of high current.
If you’d like to further decrease the noise of, or increase the lifespan of, your inverter, you can do a few things like take off the stickers and remove the adhesives so as to expose more bare hot metal to the air, upgrade the fan, and purchase a reliable thermal adhesive (arctic silver makes a reputable product) and a copper or aluminum heatsink and attach it somewhere on your device. The heatsink is more effective if attached to a hotter area of the inverter.
Since batteries are damaged exponentially more when discharged, and since battery voltage decreases with the charge level of the battery, low voltage alarm and shutdown can be very beneficial tools to ensure that your battery is not damaged and that your battery is not completely drained. It’s a good feature.
Finally, as with all products, some units are simply made poorly, and have a tendency to fail. Do your research. Eopinions.com, google products, and ebay feedbacks are useful places to check.
3D: WIRES
Your wires are going to have to be long enough to reach your equipment. They’ll need to be covered in a jacket which insulates the electrical current from objects upon which the wire will come in contact. Your wires may be exposed to chemicals like gasoline or motor oil, and may be exposed to significant heat, so you might look for wire with chemical and heat resistant jacketing. It is very important to get wires of sufficient carrying capacity to carry your current. Here is a table showing what thicknesses of copper cable are recommended for various lengths and power needs.
Table taken from rbeelectronics.com/wtable.htm
If you need more detailed
information, you can check the table on this website: http://www.powerstream.com/Wire_Size.htm,
or simply purchase wrist-sized cables from a recycling center.
Cabling is heavy and expensive. If weight is of concern, then you might consider using aluminum wire. It has more than twice the conductivity per pound as copper. Copper wiring, however, is more flexible, has greater shear strength, and is more available.
3E: POWER DRAIN PREVENTION
Because inverters will continuously draw power from your battery and can leave you stranded or kill your battery, it is strongly recommended to install a device which essentially unplugs your unit.
The Switch
A switch is a simple device which performs this function. In one position, the switch will cut current to your inverter. In the other, it will supply current. When choosing your switch, make sure it’s rated for at least the amount of DC current that is going to be passing through it. Also remember that this device causes an electrical arc when turned on or off, which can ignite fuel-air mixtures within a range of one to eight percent gasoline content. It requires manual operation.
The Relay
Relays are electrically activated switches. When a small current is applied to it’s “control circuit”, it changes the direction of another electrical pathway called the Load Circuit. If you choose to use a relay, the power from your battery to your inverter will travel through this Load Circuit. In many relays, there are two ending paths for the main power throughput: one which leads to a dead end, and one which lets electricity travel through the unit. Basically, you’re going to want to get what’s called a Single Pole Single Throw relay. If indicated, choose a Normally Open or (NO relay). Most SPST’s are NO. Here are pictures depicting how Single Pole Single Throw Normally Open relays work:
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The accessories wire on your vehicle’s ignition switch is a good wire to use for controlling our relays.
3F: SAFETY COMPONENTS
As mentioned earlier, your battery can put out a massive amount of power…enough to melt metal and destroy stuff. It can also let through enough power to let your inverter fry its internal fuse, should it have one. It’s a good idea to install a safety device to avoid equipment damage. I’ll tell you about two current limiting devices: the Fuse, and the Circuit Breaker.
The Fuse
Fuses are electrical connectors which melt or break when supplied more current than their rated breaking current, for their specified amount of time. Fuses are rated to break at certain amperages. They come in slow blow, time delay, and quick blow characteristics. When fuses break, electrical energy stops flowing through the fuse to wherever it would otherwise travel. They can only be used once, and must be replaced. This is why I recommend Circuit Breakers instead. I hate fuses.
The Circuit Breaker
Circuit breakers work a bit like fuses, but they work many times. Running a search for automotive circuit breakers will yield you circuit breakers which are suitable for direct current, but you’ll have a bunch to choose from.
Circuit breakers differ in how quickly they trip or disconnect, whether they are ignition protected or sealed, whether they are designed for DC current operation, their amperage rating, and what happens to them when they overload or ‘trip’. Internally, circuit breakers typically come with four types of current-stopping methods. They are: Thermal, Magnetic, Thermal-Magnetic, and what’s called ‘High Tech’. Thermal circuit breakers break the current once they reach a specific temperature. Magnetic Circuit breakers use a solenoid to pull at the connection in the circuit breaker, and at sufficient amperage, pulls the unit away, resulting in a break. Some units have fluid in them to help slow the breaking process, for the sake of starting motors and such. If your inverter is not suitable for very high current starting loads, you might consider avoiding purchasing such a device. Thermo-magnetic circuit breakers use a combination of these technologies.
Circuit breakers have different functionality options. Some circuit breakers don’t have any buttons. They can be auto-resetting, where they’ll repeatedly disconnect when a high current occurs. They tend to wear out. Others have reset buttons, so when a device shorts out or too much power is otherwise drawn through the breaker, you have to manually reset them. They last a bit longer. Others have a switch built into them, and you can break the flow of electricity at your will. Such is the kind that I have chosen for my project.
Here’s a copy of the tripping time for one of my circuit breakers:
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Image taken from http://bluesea.com/category/3/12/productline/specs/20
Ignition protection can be useful. If the air around the circuit breaker has a concentration of 1 to 8 percent gasoline, and you flick the circuit breaker, an arc will occur and ignite the gasoline. Ignition protected modules are sealed so that the gasoline-air mixture is not in contact with this spark. If you carry a poorly sealed can of gasoline in your vehicle, and trip the non-protected circuit breaker, you may well die. Gas stations should be of little or no concern for non-ignition protected modules, as such concentrations of gasoline are rare within the vehicle. Please observe this picture depicting typical concentrations of gasoline while refueling.
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But don’t spill gas on the ground near your breaker! I have elected not to spend the money on an ignition protected module, in part due to my impatience with finding a module rated for my amount of power, and also due to their prohibitive cost.
Getting a circuit breaker rated for too much current will protect against a significant short circuit, but could leave an inverter vulnerable to damage.
When attaching a circuit breaker, attach the wire from the electrical source to the Line input, and attach the wire traveling toward your inverter to the Load terminal.
You can find such circuit breakers at some automotive stereo installation shops, at boaters places, or online. My circuit breaker costs 52 to 75 dollars at my local boating shops, but it had cost only 8 dollars after shipping from eBay.
4. BASICS OF ASSEMBLY
4A. WIRE TERMINALS
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Image originally taken from Electrofast.com
There are many different kinds of wire terminals to choose from. Some are typically used for thicker wires, and some typically used for thinner. Marked terminals in the above picture are the ones that I’ll be talking about and using in my project. Terminals marked with letters are generally for greater current capacities, and those marked with numbers are for lesser current capacities.
The thicker types of terminals are the ones you’ll probably need to use for your inverter. The lettered terminals are popularly called Ring Connectors. Figure A is a vinyl sleeved, crimp-on connector, and figure B is a heavy duty, crimpable connector. Connector options include gold plating or other metal treatment for corrosion resistance, vinyl sleeves or heat-shrinking sleeves for electrical insulation, and funnel entry for even easier installation. On these heavier duty cables, I like to solder them and crimp them, to ensure that the connector will stay attached to the wire and help prevent shorting and general inconvenience.
The numbered connectors 1, 2 and 3 are called Butt and Quick Disconnect (QD/Disconnect) connectors. Butt connectors (#1) are for simple wire extensions. Objects 2 and 3 are the female and male portions of Quick Disconnect terminals. Quick Disconnects are for convenience of disassembly and re-assembly. For securing terminals to the wire, soldering them is always safer, but I find that my tools do an adequate job of crimping these small cables. I’ll be using these lower current wires to extend the power outlet sockets, LED’s, and switches from my inverter’s housing to the walls of my car’s center console.
4B: SOLDERING
There are detailed soldering tutorials on the Internet but I’ll give you a little rundown.
Soldering usually involves a few tools: Solder (pronounced saw-der), Flux, and a Soldering Iron. Solder is an alloy used to unite two metal joints without melting the metal of the joints themselves. It comes with lead, without lead, and with a flux or rosin core. Lead is used to make soldering easier, but if you let the tip get too hot, then a very small amount of it will become airborne and can cause minor poisoning and dumbness. Flux is an agent which decomposes into oxidation cleaning agents when heated, and Rosin is a type of flux made from pine sap. Some people recommend always using rosin core solder. A ‘soldering iron’ is a tool used for heating up the joints onto which the solder is to be applied. For larger applications, I like to use a small propane tank with a torch attachment instead of a soldering iron.
When you’re soldering, you’ll want to heat up the parts to be soldered and apply the solder directly to the part but not the soldering iron. For small parts it is recommended to apply heat on one side of the wire, feed solder to the opposite side, let the heat melt the solder and attract the solder around the wire to the soldering iron, remove the solder wire, and then remove the heating iron.
It is recommended to use the largest soldering iron tip which fits across the wire you’re going to be soldering. This helps store more heat at the tip of the tool, and provides a faster and more even heating of the part you’re going to be soldering. You want to heat the part up adequately or else the solder won’t be adequately attracted to the part, and you’ll get an unclean looking joint. These joints are less reliable and can break down the line. If you’re working on circuit boards, be careful not to overheat them and cause potentially damaging board expansion. Consider touching the circuit board for a maximum of three seconds.
Always have your parts clean. Either use super fine grit sandpaper or flux. If a part is greasy, use an electrical cleaner before applying flux or abrasive. Dirt and oxidation is like a wall between your part and the solder, blocking the chemical bond from occurring. You’ll want to keep the tip of your soldering iron free of oxidation also, as it inhibits heat transfer to your parts.
4C: ELECTRICAL INSULATION
Applying insulation to your exposed-conductor work helps avoid short circuiting and electric shock. It makes for a safe environment for yourself or someone else to probe their hands and tools.
You can use Electrical Tape or Heat Shrink. Electrical tape tends to come apart, so you can either redundantly wrap it around your work or secure it down with some kind of mechanism. Heat shrink is a plastic material which shrinks when heated. It comes in tubes. You typically have to slip the tube around the wire before soldering the joint you’re going to be applying. If made too hot, it’ll burn or melt like any other plastic, so be careful not to burn it. The advantage of using heat shrink is that it produces a cleaner looking end-product, and is less apt to break apart. I use a propane torch to apply heat for very short periods of time. I’ll be using electrical tape and zip ties for my wires.
4D: OTHER INSTALLATION TIPS
It is important to disconnect your battery when modifying wires, as high currents will flow through many of them if they come in contact with the metal on your vehicle. This can blow fuses or cause arcing and potential injury. Make sure your new connections are well electrically insulated before connecting them to your power source.
Power outlets and switches from your inverter are very often modular, and can be mounted easily to your vehicle if you make holes with dimensions which are similar to those on your inverter. LED’s can be secured with a hole slightly smaller than the LED and a little glue.
Remember that your inverter needs adequate cooling. Heat rises, circulates, and dissipates. If there are walls keeping heat from rising or circulating, then be careful.
You can test which wire is the accessories circuit on your ignition switch with a volt-ohm meter. Research how to use the volt-ohm meter and start testing cables for a current coinciding with switching the key to the Accessories position.
Remember to use adequately thick wiring when extending the connections of your inverter’s internal parts. If you’re not interested in making an accurate hole, you could make a less accurate hole and simply mount the inverter’s panel to your vehicle.
Your 12 volt vehicle lighter socket has the positive terminal as a small circular contact at the rear, and the negative terminal as the surrounding walls of the receptacle. If your small inverter only comes with a lighter socket connector, you may have to open the socket connector and see where the cables run.
Disassembly of the center console is different for every vehicle. You’ll have to find documentation relevant to the construction of your vehicle, or simply start taking things apart. Some manufacturers use screws, some use clips, some use inserts, and I’m sure some use other methods of assembly. For those of you who care about your plastic molding, it might be useful to know that they are known for breaking.
5. EQUIPMENT CONFIGURATION SUGGESTIONS
So you’ve got many options when hooking up your equipment.
For short circuit protection, you can either use fuses, or circuit breakers..
A decent circuit breaker won’t fail when there’s too much current, and will endure without maintenance, hassle, and bullshit, so I Say No To Fuses.
There are many possibilities, but I want to let you know about my five favorite options.
You can use a relay to only let power to your inverter when your car is on, you can use a switch or switching breaker and do away with hooking up a relay and be manually in control of the power feed to the inverter, or you can do a combination of relay and switch or switching breaker. There are also the options, should you not be drawing more than your lighter socket can disperse (usually 120 watts). And hook them up to the wiring for the lighter.
You can use a high powered fuse near the battery to protect against short circuits caused by messy engine work, or you can skip that precaution. My diagrams show simpler setups.
I’ll show you two lighter socket configurations, and three direct from battery configurations.
5A. LIGHTER CONFIGURATIONS
Your lighter socket may or may not be able to supply power while the vehicle is off. This is an important characteristic; If your lighter socket is automatically off while the vehicle is off then you’ll have no need for a breaker or a relay. You can simply splice the wires and run some to your inverter. If it’s on while your car is off, you’ll have to install a relay or switch. Here are the two different configurations.
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And the relay version:
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5B.
5B1.
For the battery relay setup, the advantage is that you’ll never have to remember to shut off your unit. There are also fewer complications added to the driver-vehicle interface. …It’s like an electronics product made by Apple. Unfortunately, you won’t be able to power up your inverter while you don’t have a key in the ignition. Also, unfortunately, no matter what wire you hook your relay up to, the vehicle will be drawing current for other devices in addition to your inverter, making engine-off run-time less than otherwise possible. Here’s the diagram:
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5B2.
For the Circuit Breaker approach with only a circuit breaker or switch and over-current protection device, you increase potential efficiency of your inverter setup and allow your units power while the car is off and the key out of the ignition. This allows you to leave devices on while you don’t have a key in the ignition. You’ll have to remember to switch off your power when you leave. This option can be cumbersome for the regular user, and a battery death trap for someone with poor habit forming practices.
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5B3.
The hybrid system involves a relay and a switch or switching circuit breaker. Two breakers will have to be used in this system. I recommend one switching circuit breaker for your relay bypass feature, and one manually resettable circuit breaker for use with the relay feature. You’ll still have to remember to turn off your manual over-ride, but you won’t have to turn it on or off if just needing electricity for your trip.
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I knew hardly anything about batteries, wiring sizes, relays, fuses, breakers and inverters before starting this project, so you can infer that I am at least a competent learner and have the ability to provide instructional documents deserving of at least moderate appreciation.
I like to know that my efforts are valued, and I hope to perform this type function in society and support myself with it.
So if you like what you see, and would like to see more of it, please consider sending a Paypal donation to CreateJunkMail@Yahoo.com, or donate to
Best wishes.
Air powered car
blog posted by BulbMedia Tue, 2008-06-10 17:22 Tags:
This alternative energy powered car is the best I have seen. An air powered car does not polute, uses reusable energy, and is inexpencive to buy and operate. This is technology that Americans should demand to have. It will not solve our gas crisys or polution problems, since gas powered cars will still be needed for heavy duty situations such as big riggs, and construction. But it is an ideal solution for the common everyday American.
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