How to Have Electricity in your Vehicle Home:
By Robert Wells
You have made the decision to start a new life by giving up your house or apartment
and moving into your vehicle. But wait a minute, what will you do for power?
These are pretty important questions. If you don't think electricity is important,
turn off the main breaker to your house and do without it for a week. After living in
my van for a week without power, I knew I had to have it. I like to watch TV and
DVD's. I want to be connected to the web via my laptop. I like the convenience of a
microwave. So I found a way to have electricity in my box van. There are several
ways to do this. We'll start with the easiest, cheapest and simplest and move onto
the more expensive and difficult.
1) Use the car starting battery.
While this works, it is not a good idea. You just use the starting battery of your car
to run your "house" needs. Your car probably has a cigarette lighter. Since many 12
volt items come with a plug that goes into the cigarette lighter all you have to do is
plug it in and it is running off your car battery. For example, many stores sell 12
volt, nine inch TV/VCR combos. For lights the simplest thing is to look around for a
12 volt trouble light at an auto parts store. I have bought them with a cigarette
lighter plug in or with alligator clips to clip on the battery. They have 50 watt bulbs
which draw too much power so I replaced mine with 12 volt compact florescent I
bought off Ebay, or they are available on the web, just do a Goggle search. They
put out the same amount of light but only draw 13 watts.
For 110 volt items, you can buy something called an inverter. This allows your 110
volt items to be powered by your cars 12 volt battery. They can be bought for
about $40 at WalMart. You plug the inverter into your cigarette lighter and then
plug your laptop, TV, or battery charger into it.
This works fine as long as you are driving, or running your car often. The problem is
that the starting battery in a car is not designed to be discharged and recharged.
It should be left nearly full all the time, otherwise it will loose it's ability to hold
any charge. So if you are parked overnight watching a couple of movies and running
your laptop. The next morning your battery will probably be dead and your car
won't start. Very inconvenient! Do that a few times and you will be buying a new
battery. Very expensive! While this is cheap and easy, it is also the riskiest way to
get power.
There are better ways.
2) Buy a Backup Battery Jumper.
These are small self-contained batteries with attached jumper cables. They are
intended to be carried with you in your trunk and jump start your car if your
battery dies. You can buy them with built in tire inflater's, lights, and even
inverters to run 110 volt items. Nearly all come with an outlet to allow you to plug
cigarette lighter items in. Make sure you get one that can be charged from your
car's cigarette lighter so you can recharge it while you drive. These have the
advantage of providing you with power, and they won't leave you stranded with a
dead battery. Sam's Club sells one for about $45. However, the batteries in these
are not very good. They are small, will run down quickly with use, and will fail after
a few discharges and recharges. So they really aren't a good answer either.
3) Install a second deep cycle battery.
This solution is the way to go, so we will spend a lot of time here explaining how to
do it.
Which Battery To Buy
We need a deep cycle battery because they are designed to be discharged and
charged hundreds, even thousands of times without harm to the battery. Also they
have a much larger capacity. The capacity of Deep Cycle batteries is measured in
amp hours (Ah). Let's look at an example. You have a 9 inch TV that draws 50 watts
of power and a light bulb burning that also draws 50 watts of power, so you are
using 100 watts of electricity. To determine amps you divide watts by volts, so
we have 100/12, which is about 8 amps. So every hour we draw 8.3 amps. WalMart
sells a 105 Ah battery for about $65. You might think that means you can run your
TV and light for 12 hours, but it doesn't work that way. Deep Cycle batteries
should not be run down beyond 50% of their capacity or they will be damaged. So
our cheap WalMart battery only gives us 55Ah of power, or about 7 hours for our
TV/light combo. I have something called an 8D battery in my camper. I bought it at
Sam's Club for $116 and it has 225 Ah of capacity. At some point I will add a
second one wired to the first giving me a total of 450 Ah of life. Then I could run
our TV/light combo for 27 hours. Remember I said I replaced my regular 50 watt
bulb with a 13 watt compact fluorescent? Let's do the math with it instead. 50
watts and 13 watts total 63 watts, divided by 12 means I am drawing 5.2 amps
instead of 8.3. So my two 8D batteries will run the TV/light combo for 43 hours.
That one change gave me another 16 hours of use. Conservation is very important to
us car/van/RV dwellers. I would probably use the lights and TV no more than 4
hours a day, so I could go 11 days without recharging the batteries.
So we want to buy a battery with the largest capacity in amp hours we can, right?
Not necessarily. The more capacity a battery has the larger and heavier it is. My
8D is about one foot across and two feet long. It weighs 130 lbs. It's all I can do
to pick it up into the camper. It's a great deal, but if you don't have room and can't
move it, it's not a good choice for you.
Another big consideration is cost. You can buy a cheap deep cycle battery at
WalMart for $65, or you can pay $300 for a Trojan, gel cell or AGM battery. If
you only have $65 then your decision is made, you can't beat the WalMart price.
For just a little more Sam's Club sells 6 volt golf cart batteries for $50 each. You
need to buy 2 and wire them together to make them 12 volt. Wired together they
have 110 Ah capacity. So why are they better than the WalMart battery, it has
nearly the capacity and costs less? The first few years they would be just as good.
But after that the difference in quality will become obvious. The golf cart batteries
are true deep cycle and will last much longer. The 8D gives you double the capacity
for a few dollars more and will last just as long, so why not get it instead? For
some people it's size and weight are overwhelming so the golf cart batteries are
worth it. Also, if one cell of the golf cart battery goes bad, you can just replace
that one battery instead of having to buy a whole new 8D. A company named Trojan
makes some of the very best golf cart and deep cycle batteries. Their T105 can be
ordered for less than $100 each. A pair will cost $200 and give you 225 Ah of
storage. They are better batteries and will last longer.
So far we have only talked about traditional flooded wet cell batteries. There are
two newer batteries out now called gel, and AGM (Absorbent Glass Matt). They
have the advantage that they are sealed, so that they don't vent water or hydrogen
so they are zero maintenance and zero risk. For a great discussion of these and all
batteries go to:
Windsun.com
They recommend against the gel batteries as do I. AGM batteries have all the
advantages of gel, and none of gels disadvantages. An AGM charges faster, and
discharges slower than a gel battery, nor are they as fragile, so unless you can get
a gel really cheap, buy AGM. Again, they will cost double or triple the cost of a
flooded cell battery, but their advantages may be worth it to you.
Where Will I Carry It?
If you are living in a car, then you don't have much room for a battery bank.
Whatever you drive, you must also be aware of weight since the more weight you
carry, the harder your engine works, and the less mpg you get. If you have a gel or
AGM battery, you can put it anywhere it will fit, even on it's side since it can't leak.
Maybe you can fit it on it's side underneath the drivers seat? It's a different
story with regular flooded wet cells. They must be maintained regularly by keeping
them full of water and cleaned off. They also vent hydrogen gas which is very
corrosive and explosive. Ideally they will not be in your living area. So where can
you put 100 lbs of battery? One possibility is on the roof in a storage box. To be
honest with you, I lived in a box van for 6 years with an 8D under my bed without
any problem. Was it dangerous? Everyone tells me it was, but I never had any
problem. I can't recommend you do it, I can only report my experience. For my
current camper, I bought something called Hydrocaps. They replace the battery
cap that came on my battery and virtually eliminate water and hydrogen from
escaping. Then I went to WalMart and found a plastic storage box that will hold my
battery and keep it in there. That should contain the little hydrogen that does
escape. So now I just keep it in the camper with me. Here is a discussion of
Hydrocaps:
Hydrocaps
How will we Charge Our Batteries?
Now we know which battery we will buy and where we will put it. Here are four
ways to keep it charged.
1) Car alternator: We have a built in source of electricity in our car's alternator,
so lets tap into it. This is fairly simple:
2) For several reasons I won't go into, just charging off the alternator probably
won't be adequate to keep your battery fully charged. A great answer is a
generator. You may think a generator isn't for you because of their many problems.
There isn't room in your car/van/RV for one. They are too heavy to lift in and out
and too hard to start. When they are running, they are so loud they drive you crazy,
plus they burn too much gas. All of that is true of past models of generators, but
fortunately none of it is true of a new generation of Honda and Yamaha generators.
They are tiny, light, quiet, start easily and sip gas. And they will run very close to
forever. You may think I am exaggerating but seeing is believing. Visit a Honda or
Yamaha dealer and be amazed how practical they are for car/van/RV living. The
one problem is that they are fairly expensive. You can get the 1000 watt model for
about $700 over the net. If you have the money, they are worth it.
3) Park in a RV park once a week to charge your batteries. While you are there
you can do your laundry, wash your dishes and take a hot shower. Many offer cable
TV and Internet access as well. If you pay $20 a week, that is $1040 per year. You
could have paid for a generator and had money left over for that. Of course $20 a
week is much easier to come up with than $600 cash so maybe it is worth it to you.
Whether you are charging your battery at a RV park or with a generator, you will
need a battery charger. Your first thought is that any old automotive battery
charger will do, but that isn't correct. Deep cycle batteries are fussy on how they
like to be charged. A regular charger will lead to poorly charged batteries and
their premature death. What we need is a "smart" charger. Very often they
literally will say "smart" on the package. These are three stage chargers that
automatically go through bulk, absorption and trickle, phases. They will charge your
battery faster and make them last much longer.
4)Install solar panels. This is the ideal solution but it has several drawbacks. First
it is very expensive. A single 100 watt panel with controller and wiring will be at
least $600. The second is that they don't produce a lot of power. Probably not
enough to keep your battery charged unless you put up more panels. Second, on
cloudy days, during winter, or if you are parked in trees, they deliver even less
power. Third, you may not have room for them on your roof. If you have the room
and money this is a great way to go. But you don't get much bang for your buck.
This has been a brief overview of RV electrical systems. I have tried to keep it
simple enough to not overwhelm you, but informative enough to help you. A Google
search of any of these topics will bring you a wealth of information. A good book
which covers all this is:
"Managing 12 Volts:
How To Upgrade, Operate, and Troubleshoot 12 Volt Electrical Systems"
By Harold Barre
I bought mine off Amazon.com.
and moving into your vehicle. But wait a minute, what will you do for power?
- What will you do for lights?
- How will you recharge your laptop or camera?
- How will you watch TV or DVDs?
- In the heat of the summer, how will you run a fan?
- In the cool of the winter, how can you power a 12 volt blanket?
- What if I want a microwave?
These are pretty important questions. If you don't think electricity is important,
turn off the main breaker to your house and do without it for a week. After living in
my van for a week without power, I knew I had to have it. I like to watch TV and
DVD's. I want to be connected to the web via my laptop. I like the convenience of a
microwave. So I found a way to have electricity in my box van. There are several
ways to do this. We'll start with the easiest, cheapest and simplest and move onto
the more expensive and difficult.
1) Use the car starting battery.
While this works, it is not a good idea. You just use the starting battery of your car
to run your "house" needs. Your car probably has a cigarette lighter. Since many 12
volt items come with a plug that goes into the cigarette lighter all you have to do is
plug it in and it is running off your car battery. For example, many stores sell 12
volt, nine inch TV/VCR combos. For lights the simplest thing is to look around for a
12 volt trouble light at an auto parts store. I have bought them with a cigarette
lighter plug in or with alligator clips to clip on the battery. They have 50 watt bulbs
which draw too much power so I replaced mine with 12 volt compact florescent I
bought off Ebay, or they are available on the web, just do a Goggle search. They
put out the same amount of light but only draw 13 watts.
For 110 volt items, you can buy something called an inverter. This allows your 110
volt items to be powered by your cars 12 volt battery. They can be bought for
about $40 at WalMart. You plug the inverter into your cigarette lighter and then
plug your laptop, TV, or battery charger into it.
This works fine as long as you are driving, or running your car often. The problem is
that the starting battery in a car is not designed to be discharged and recharged.
It should be left nearly full all the time, otherwise it will loose it's ability to hold
any charge. So if you are parked overnight watching a couple of movies and running
your laptop. The next morning your battery will probably be dead and your car
won't start. Very inconvenient! Do that a few times and you will be buying a new
battery. Very expensive! While this is cheap and easy, it is also the riskiest way to
get power.
There are better ways.
2) Buy a Backup Battery Jumper.
These are small self-contained batteries with attached jumper cables. They are
intended to be carried with you in your trunk and jump start your car if your
battery dies. You can buy them with built in tire inflater's, lights, and even
inverters to run 110 volt items. Nearly all come with an outlet to allow you to plug
cigarette lighter items in. Make sure you get one that can be charged from your
car's cigarette lighter so you can recharge it while you drive. These have the
advantage of providing you with power, and they won't leave you stranded with a
dead battery. Sam's Club sells one for about $45. However, the batteries in these
are not very good. They are small, will run down quickly with use, and will fail after
a few discharges and recharges. So they really aren't a good answer either.
3) Install a second deep cycle battery.
This solution is the way to go, so we will spend a lot of time here explaining how to
do it.
Which Battery To Buy
We need a deep cycle battery because they are designed to be discharged and
charged hundreds, even thousands of times without harm to the battery. Also they
have a much larger capacity. The capacity of Deep Cycle batteries is measured in
amp hours (Ah). Let's look at an example. You have a 9 inch TV that draws 50 watts
of power and a light bulb burning that also draws 50 watts of power, so you are
using 100 watts of electricity. To determine amps you divide watts by volts, so
we have 100/12, which is about 8 amps. So every hour we draw 8.3 amps. WalMart
sells a 105 Ah battery for about $65. You might think that means you can run your
TV and light for 12 hours, but it doesn't work that way. Deep Cycle batteries
should not be run down beyond 50% of their capacity or they will be damaged. So
our cheap WalMart battery only gives us 55Ah of power, or about 7 hours for our
TV/light combo. I have something called an 8D battery in my camper. I bought it at
Sam's Club for $116 and it has 225 Ah of capacity. At some point I will add a
second one wired to the first giving me a total of 450 Ah of life. Then I could run
our TV/light combo for 27 hours. Remember I said I replaced my regular 50 watt
bulb with a 13 watt compact fluorescent? Let's do the math with it instead. 50
watts and 13 watts total 63 watts, divided by 12 means I am drawing 5.2 amps
instead of 8.3. So my two 8D batteries will run the TV/light combo for 43 hours.
That one change gave me another 16 hours of use. Conservation is very important to
us car/van/RV dwellers. I would probably use the lights and TV no more than 4
hours a day, so I could go 11 days without recharging the batteries.
So we want to buy a battery with the largest capacity in amp hours we can, right?
Not necessarily. The more capacity a battery has the larger and heavier it is. My
8D is about one foot across and two feet long. It weighs 130 lbs. It's all I can do
to pick it up into the camper. It's a great deal, but if you don't have room and can't
move it, it's not a good choice for you.
Another big consideration is cost. You can buy a cheap deep cycle battery at
WalMart for $65, or you can pay $300 for a Trojan, gel cell or AGM battery. If
you only have $65 then your decision is made, you can't beat the WalMart price.
For just a little more Sam's Club sells 6 volt golf cart batteries for $50 each. You
need to buy 2 and wire them together to make them 12 volt. Wired together they
have 110 Ah capacity. So why are they better than the WalMart battery, it has
nearly the capacity and costs less? The first few years they would be just as good.
But after that the difference in quality will become obvious. The golf cart batteries
are true deep cycle and will last much longer. The 8D gives you double the capacity
for a few dollars more and will last just as long, so why not get it instead? For
some people it's size and weight are overwhelming so the golf cart batteries are
worth it. Also, if one cell of the golf cart battery goes bad, you can just replace
that one battery instead of having to buy a whole new 8D. A company named Trojan
makes some of the very best golf cart and deep cycle batteries. Their T105 can be
ordered for less than $100 each. A pair will cost $200 and give you 225 Ah of
storage. They are better batteries and will last longer.
So far we have only talked about traditional flooded wet cell batteries. There are
two newer batteries out now called gel, and AGM (Absorbent Glass Matt). They
have the advantage that they are sealed, so that they don't vent water or hydrogen
so they are zero maintenance and zero risk. For a great discussion of these and all
batteries go to:
Windsun.com
They recommend against the gel batteries as do I. AGM batteries have all the
advantages of gel, and none of gels disadvantages. An AGM charges faster, and
discharges slower than a gel battery, nor are they as fragile, so unless you can get
a gel really cheap, buy AGM. Again, they will cost double or triple the cost of a
flooded cell battery, but their advantages may be worth it to you.
Where Will I Carry It?
If you are living in a car, then you don't have much room for a battery bank.
Whatever you drive, you must also be aware of weight since the more weight you
carry, the harder your engine works, and the less mpg you get. If you have a gel or
AGM battery, you can put it anywhere it will fit, even on it's side since it can't leak.
Maybe you can fit it on it's side underneath the drivers seat? It's a different
story with regular flooded wet cells. They must be maintained regularly by keeping
them full of water and cleaned off. They also vent hydrogen gas which is very
corrosive and explosive. Ideally they will not be in your living area. So where can
you put 100 lbs of battery? One possibility is on the roof in a storage box. To be
honest with you, I lived in a box van for 6 years with an 8D under my bed without
any problem. Was it dangerous? Everyone tells me it was, but I never had any
problem. I can't recommend you do it, I can only report my experience. For my
current camper, I bought something called Hydrocaps. They replace the battery
cap that came on my battery and virtually eliminate water and hydrogen from
escaping. Then I went to WalMart and found a plastic storage box that will hold my
battery and keep it in there. That should contain the little hydrogen that does
escape. So now I just keep it in the camper with me. Here is a discussion of
Hydrocaps:
Hydrocaps
How will we Charge Our Batteries?
Now we know which battery we will buy and where we will put it. Here are four
ways to keep it charged.
1) Car alternator: We have a built in source of electricity in our car's alternator,
so lets tap into it. This is fairly simple:
- You need a cable long enough to go from your cars battery to your house
battery. To measure this, tie one end of a string to the positive post of your
car battery and wind it down, along the frame, and up to where the battery
will be. Measure the string and this is how long your cable needs to be. Your
town or a town nearby probably has a battery store or auto electric shop who
will custom make a cable for you. Tell them the length you need and the size.
With cables, the smaller the number, the bigger the physical size of the cable.
A size 4 cable should be big enough for simply charging the battery. Ask your
retailer. They will also put the ends on for you. - You will probably need to drill at least a half inch hole through the floor to get
the cable in. Be sure and put a rubber grommet in the hole so the sharp metal
doesn't wear the rubber off the cable causing a short. - Your house battery needs to be grounded. Grounds are very important, so
take your time and do it right. The best way is to run a 10 gauge wire from the
negative of your house battery, through the hole you just drilled and to your
frame. Look around and find a hole in the frame. I was lucky and found a hole
close by. If you can't find a hole, look for a bolt to take off and use it for a
ground. If you can't find anything, drill a new hole. Scrub the area around the
connection with a tool until you have shiny new metal. I used an old knife. Then
I put on a thin layer of Vaseline to keep rust from forming. You may be
tempted to go directly to the body because it's so easy, but there isn't
enough metal mass to be an adequate ground. That's because bodies are
attached to the frame with a rubber gasket to give a better ride. - Next, attach the cable ends to the positive pole of the house and starting
battery and you are in business! Your house battery is being charged by your
car alternator. However, we still have a problem, if we use too much juice in
our house battery, it pulls whatever is needed from the starter battery. If it
draws too much, it won't start the car and we are stranded. Do that a few
times and we are buying a new starting battery. There are three solutions to
this problem.
- The first and simplest is a battery selector switch. You attach the cable
from the starting battery to this switch and run a cable from the switch
to the house battery. When you are going to be using the house battery,
you turn the switch to off. This isolates the house battery from the
starting battery so it can't draw it down. The next day, when you are
done camping and about to drive off, turn the switch to on and now the
two batteries are connected again and the house battery is being
recharged. Simple and easy. But what if you forget to turn the switch
off? You run the risk of running your starting battery down and being
stranded. One way around this is replace your starting battery with a
marine starting battery which will not be damaged if you forget to turn
the switch off. And carry a jumper battery as discussed earlier. - The next solution is a little more complex but solves all of our problems.
It is using a continuous duty solenoid between the two batteries. A good
auto store will sell these or you can google continuous duty solenoid and
order one over the net. Don't buy an intermittent duty solenoid, it won't
last. It must say continuous duty. Once you have it, you mount it to the
firewall of your vehicle. A cable runs from the starting battery positive
post to one of the large studs on the solenoid. A cable leaves the other
large post and runs back to the positive post of your house battery. On
some solenoids there will be two smaller posts. One is for a ground to the
frame, the other is to a hot wire in the vehicle wiring harness. Some
solenoids are self-grounding, so they only have one of the small posts.
The screws that secure it to the firewall act as the ground. If that is
what you have, take extra care to have a good clean connection for the
ground. If there is paint on the fender or firewall where you are
attaching the solenoid, you must scrap the paint off so that you have a
clean metal-to-metal connection. That thin layer of paint will prevent a
good ground. Whether you have one or two smaller posts, you must run a
wire to the vehicle wiring harness. Wherever you splice in, it must be
after the ignition, so that when you turn the key off, power is turned off
to the solenoid as well. A good easy place for this is the power to the
radio since we know that when you turn off the key, the radio losses
power and turns off. What happens is that when you turn on the key,
power goes to the solenoid which activates a magnet inside it. The magnet
lifts a bar which makes a connection between the two large posts,
allowing charging current to flow from the starting battery to the house
battery. When you turn the key off, current no longer flows to the
solenoid, the magnet turns off, the bar falls and there is no longer a
connection between house and starting battery. That means that if the
engine is running, the house battery is being charged, and if it is off, the
house battery can not run down the starting battery. The best of both
worlds! Absolutely no drawbacks. - Another solution, and by far the most common, is using a battery isolator.
These are commonly available at any auto parts or RV store. Because
these have a half volt drop between the house and starting battery, I
don't recommend them. Therefore, I am not going to cover them very
much. Just follow the instructions that come with them if you want to use
one.
2) For several reasons I won't go into, just charging off the alternator probably
won't be adequate to keep your battery fully charged. A great answer is a
generator. You may think a generator isn't for you because of their many problems.
There isn't room in your car/van/RV for one. They are too heavy to lift in and out
and too hard to start. When they are running, they are so loud they drive you crazy,
plus they burn too much gas. All of that is true of past models of generators, but
fortunately none of it is true of a new generation of Honda and Yamaha generators.
They are tiny, light, quiet, start easily and sip gas. And they will run very close to
forever. You may think I am exaggerating but seeing is believing. Visit a Honda or
Yamaha dealer and be amazed how practical they are for car/van/RV living. The
one problem is that they are fairly expensive. You can get the 1000 watt model for
about $700 over the net. If you have the money, they are worth it.
3) Park in a RV park once a week to charge your batteries. While you are there
you can do your laundry, wash your dishes and take a hot shower. Many offer cable
TV and Internet access as well. If you pay $20 a week, that is $1040 per year. You
could have paid for a generator and had money left over for that. Of course $20 a
week is much easier to come up with than $600 cash so maybe it is worth it to you.
Whether you are charging your battery at a RV park or with a generator, you will
need a battery charger. Your first thought is that any old automotive battery
charger will do, but that isn't correct. Deep cycle batteries are fussy on how they
like to be charged. A regular charger will lead to poorly charged batteries and
their premature death. What we need is a "smart" charger. Very often they
literally will say "smart" on the package. These are three stage chargers that
automatically go through bulk, absorption and trickle, phases. They will charge your
battery faster and make them last much longer.
4)Install solar panels. This is the ideal solution but it has several drawbacks. First
it is very expensive. A single 100 watt panel with controller and wiring will be at
least $600. The second is that they don't produce a lot of power. Probably not
enough to keep your battery charged unless you put up more panels. Second, on
cloudy days, during winter, or if you are parked in trees, they deliver even less
power. Third, you may not have room for them on your roof. If you have the room
and money this is a great way to go. But you don't get much bang for your buck.
This has been a brief overview of RV electrical systems. I have tried to keep it
simple enough to not overwhelm you, but informative enough to help you. A Google
search of any of these topics will bring you a wealth of information. A good book
which covers all this is:
"Managing 12 Volts:
How To Upgrade, Operate, and Troubleshoot 12 Volt Electrical Systems"
By Harold Barre
I bought mine off Amazon.com.
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