Caravan Electrical Connections

KENAX
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Electricity in the Caravan:

Of course everyone and their dog argued against me that it was simply not possible, but no, the solar panels are working absolutely magnificently and I am quite happy with them. My electrical needs are one to three laptops worth for 8 hours a day. For this I was advised to get two larger 110 Watt solar panels, which nicely fit on the top of my roof. I got them installed by a welder, who designed it so that they could be tilted in various ways and directions. But I don’t even bother doing that, at least during the summer, as they seem to pick up enough light with a moderate sun angle, and even when cloudy. Furthermore, by being down and flat, they are not really visible, and hence not an attraction for local starving thieves. Most people are surprised to learn I have solar panels, but then I don’t have a caravan but a discretely designed truck which doesn’t attract attention in that department.

Now during the day, and evening, I’ve been watching the regulator, which shows the strength of the battery, solar power, and consumption of what electricity I am using, and have learned to sense my limits. With these two solar panels, hence at 220 W, I find I can accomplish a lot during a sunny day, but what you need to do is look at consumption usage per device. Which is usually easy enough by picking up that little converter, the little black box between your computer and the electrical outlet, and read its power consumption levels. A light laptop can use about 50 W, but heavier laptops more, so look on the power rating on the back and do a simple calculation <show calculation>. So an input of 16V and 3.5Amps should work out to 56 Watts, like my laptop, and low enough that my 460 AmpHours of battery power seem to last right until the morning. Watch your caravan’s battery power and try to keep it fully charged by the end of the day if you expect to do work during the evening.

The 500W 240V inverter front left, 300W 120V inverter right, regulator in background (all still to be organised)

My regulator has excess power output terminals, so when the sun is high and dry and I am not using its full use, a second output starts releasing the excess energy. My battery could be fully charged, I could have several devices running at the same time, but still I have excess energy. So if everything is at full capacity, it is good to have something plugged into this output to take advantage of the extra power once it is generated. Although I don’t have it set up yet and I still have to check out some things, what I have in mind is the fridge and the car battery. For the car battery, I have to check whether the extra charge could somehow damage the alternator. Anyway, while being parked somewhere for an extended period of time and not driving, I am thinking the extra energy could be appropriately used to keep the car battery at 100%, which those kinds of batteries should be kept at. Not only will this extend your battery’s life, but it will keep it fully charged once you want to rev up the beast and take off to the next destination. Or perhaps more important than this is the fridge. I don’t really need a fridge and think it is unnecessary, as I buy what I eat every day, like fresh fruits, vegetables, maybe cheese and fresh bread, can of sardines etc. Or make a dinner that evening using the fresh vegetables, maybe fish right out of the ocean, rice which lasts forever, etc. etc. So I really don’t see the need for a fridge. But maybe you could put spices in there so they don’t heat up and fade in flavour. I got a basic cooler with a built in electric cooler (by electricity it reduces the inside temperature 20C from the outside temperature, and was only a little more expensive than a regular cooler), so I can grab it and take it to the beach as well. Practical is always key.

Charging the car battery from the boat battery,
from the sun

So the solar panels hook up to the regulator, which then charges the boat batteries. When the boat batteries are fully charged and there is excess power, from the regulator comes the additional 12V with which you can power extra things. Otherwise, the 12V boat batteries can be used to power various things in general. If you are lucky, you can power some 12V devices directly. Or you might have a converter from 12V into 6V, for example, but this can get expensive, as you would need separate converters for all devices having different voltages. The easiest is to hook up an inverter to the battery, which converts the 12V into 240V. I also have an inverter I bought in the US and which converts the 12V to 120V. Once you have that, you simply plug in an extension chord and all your devices into that. But by going from 12V to 240V, and then back down to 6V, means a certain loss of energy for the conversion process, I think as much as 30%. So I mostly use the 120V converter, as a lot of my devices can plug into either 120 or 240V (again, look at the little black box with your device’s power chord to see what input it can handle). But I must warn you here that you should be very careful about turning off the inverter when devices are still plugged into it and turned on. For safety then, I use a power bar, which is basically an extension chord with its own switch, and inside it various fuses. Not too expensive but definitely worth it, as I already fried some devices like this. And you should also have a fuse between the battery and the regulator (refer to your regulator’s installation instructions). So, whenever leaving the truck (I like to turn everything off, because the last thing I want to return to from a pleasant walk is a pile of smoldering ashes), first turn off the extension chord, and then the inverter, to avoid any unwanted power surges. And what concerns the inverter, they come in different wattages. So you’ll have to do some math to determine how much maximum wattage power you may need at any one time. I have a 300W 120V inverter, which seems plenty to run almost everything (at once), and a 500W 240V inverter for extra power. But the more you have running, obviously the quicker you’ll kill your battery, if there is not enough sunshine to power everything. So keep a close eye on the regulator and soon enough you’ll have a good feel of what you can get away with just by looking outside.

Charging under the shade, and to right, getting the last snatch of sun as it descends to the west.

And all this, amazingly, I installed myself. But when doing so, be very very careful about certain things. For example, two 230 Ah batteries in parallel makes 460 amp hours of energy. Or perhaps 460 hours worth of power to run a 1 amp device, like most laptops. I asked someone what would happen if I shorted the plus and minus contacts on such a power house and he said, "Well, you won’t really destroy the battery but drain it rather quickly. On the other hand, if it contacts that big metal rod is see holding up your bench seat and which I see is about 1 cm away from each contact, it will basically melt it into nothing, at the section between the contacts." So definitely enough power to fry your little heart if you held the plus in one hand and the minus in the other, for example. And considering that the minus is supposed to be connected to the frame of the vehicle, if your ankle is touching the leg of one of the front seats (which is obviously bolted to the metal frame of your car) and your left finger accidentally comes in contact with the plus on the battery, or any of the wires feeding out of it, you are fried my friend. So when setting up your system, either get an electrician (I tried but failed, and hence was forced to set this up myself, with my brother), or be extremely careful. Like my dad, the electronic engineer, said, "When working with electronics, you should always have one hand on what you are doing and the other one up your ass." That way you will not create a circuit going through your heart, which will mean immediate death. And once you are finished, make sure to think very careful about what could happen. If you get into an accident and the battery slides forward, can the contacts touch something? If so, bolt them to the floor, like I did. Or one person suggested fastening them somehow under the truck. And you should surround the contacts with all sorts of rubber and other non conductive material, protecting the region with wood so little children fingers could not get to it, and keep in mind that someone might spill water here or there. So be very careful about this my friends. 12V may seem like a small number, but it’s the amperes that kill you, and how or where they travel through your body.

Hooking Up The Caravan Batteries

I hooked them up in parallel as suggested by the salesman, with the regulator hooked up to one of the batteries, but after a year and a half it seems that the battery closest to the regulator is much weaker, as if it has always been drained and charged first. So I would suggest you hook them both up to the regulator separately. Now that one seems much weaker than the other, once it gets dark I disconnect one of them and discharge them one at a time, since the weaker battery seems to drain the stronger one. If one is more drained than the other by morning, perhaps charge them separately.

Caravan Battery Maintenance and Power Management

I am told that these boat batteries should be maintained at a total charge of between 50 and 80%, which is hard to regulate if the sun is beaming all day long, meaning at 100% all day. But more importantly it is not supposed to go too low, I am told especially below 10.6V. At this level the electrical chemistry in the battery acid gets so low that the lead plates within the battery get damaged and you seriously reduce the capacity of the battery, so keep your eye on the regulator to make sure it is not getting too low. When I hit 20% I like to turn everything off, and I find that the battery can actually climb back to 80% after about four hours. As if my consumption rate was too high, draining the battery quickly, but that there is still lots of latent juices to draw from, once it has climbed back up.

I am learning this constantly, so I will try to update this section over time, but I believe it is quite important. For example, I find that when I use my fancy wifi antenna which hooks up through the usb port on my computer and the sun has gone down, I can kill the battery quite quickly. Or playing a movie through the laptop’s internal DVD player can kill the battery before the movie ends. But I can write emails and do simple computer work right until the morning without putting a dent into the battery capacity at all. Or even charging a mobile battery requires a lot of consumption. So I charge all my other batteries (I don’t even buy disposal pen batteries anymore and everything is rechargeable, so I’m like totally green dudes) when there is enough sun and remove my battery from the laptop when in night mode. In night mode, I might put the battery into my laptop, wait a few seconds until it registers, then disconnect the power source and spend a few minutes transferring a movie to the laptop’s harddrive. This process alone has killed my boat batteries, but the laptop batteries seem to be able to handle these higher consumption levels. Or I’ll use the laptop batteries for wifi internet once the sun goes down, and switch back to boat batteries once I’m offline. Seems that watching a movie straight from the harddrive sucks much less energy. If I want to get fancy, I can have laptop speakers with their own power source/batteries running through the earphone output, but even adding the docking bay to my laptop, which has better speakers and the DVD drive, can suck noticeably more power. So you’ll have to play around with this and experiment. Just make sure you do not drain your battery too much. It would definitely be a worthwhile investment to get one of those voltage meters. They are not expensive and you can get one in almost any electro shop. With this I can tell when my pen (AA or AAA) batteries are getting weak and when I should recharge them if I don’t want to run out of power or music at some inconvenient time, or know when I should take advantage of a sunny day. Or if I am parked somewhere for a longer period of time, I can check my car battery, as the alarm system slowly sucks off that, or the car radio, or some of the lights. Car batteries should remain at near 100%, so you don’t want to kill the capacity of those either. Once I found myself charging those from the sun as well, using jumper cables hooked up to my boat batteries, charged by the sun (pictures above). Just remember that these car batteries are also grounded to the vehicle, so really think things through before hooking up anything. A basic lesson from an electrician or car mechanic could definitely be a worthwhile investment. After all, it’s your life. And screwing up the polarities on your batteries could cause them to explode, with battery acid in your face, and you can kiss your sight goodbye. I read once that you should have a damp cloth over car batteries when jump starting from another vehicle. And it is important what order you hook things up in. I generally remember that the plus/positive end must always be connected whether connecting or disconnecting the minus/negative/ground end.

Now catching the sun as it rises from the east on the other side of the peninsula,
where I like to crash so I can see the sun fill the truck in the early morning.

And depending on your battery, you should check the level of the battery acid in it from time to time. They say you should pour some distilled water into any of the chambers if the level gets too low, which would expose any portion of the lead plates. If those get exposed to the air, they will get ruined in those sections, so check up on this from time to time. I will try to find some good links to this. Just be careful and study all this!

And when charging up mobile and those other NH3 <.. batteries, it is always good to discharge them as much as you can before fully charging them. I know they say that the newer ones don’t really have a memory effect, but that’s baloney and they still do. These types of batteries have only so many cycles, and it is better to empty them fully before charging them fully. That way their capacity will remain at maximum, and you will not have to buy replacements as quickly. Actually, if you want to be smart like me (well, you can at least try, no?), since you’re going to buy replacements at some point anyway, go right ahead and buy those replacements in the very beginning. For your mobile, and backup pen batteries for your other devices. Use your device until the battery is totally dead, then simply throw in your fully charged backup battery and keep going. Not only will this mean that you have double the capacity, if you ever go camping or somewhere in the boonies without the possibility to recharge, but you will know exactly when to recharge your battery, you will get much longer life out of them, AND maintain their maximum capacity.

For light, buy lots of candles. It makes for great ambient lighting and doesn’t suck up unnecessary power. Or if it is a cloudy day and you are short of battery power, forget about movies and the radio and go natural. Pick up your guitar, or if it is a rainy day, just listen to the pitter patter – a soothing sound indeed while reading. Or just look outside at the ocean and watch the rain fall on the surface. Forget about all the gadgets, get out of the truck and dip in the ocean under the moonlight and rainy sky. That TV thing is a waste of time and made for city folk who have been ripped from the womb of nature. [However, if you really do need a TV, you can get an excellent and not so expensive USB thing which turns your laptop into a TV (a regular TV will suck up way too much juice). Analogue or digital, language stereo and the works. Invest into a half decent antenna system and you're set. Just research various products on the internet first, before buying.]

In conclusion, even on a cloudy day, I find I can easily survive off the sun. Perhaps charging my various batteries (I only use rechargeable AA batteries now, so I can be fully environmental) at different times of the day, such that my digital cameral, portable radio and everything I have powers off the sun. If you get tired of the sitting in the truck, you can find a pub which will let you plug into their socket, so bring a splitter so you can secretly charge everything else at the same time. Or while in the internet café, or the restaurant with free wifi connection. I survived without a problem this way for a month in Prague before I hooked up my solar panels. But I have several backup batteries for my laptop, so a little juggling was required. In all, I find the concept beautiful. Right down to a hot and sunny day, with excess energy in my system, using electricity to create a little bastion of cool in a portable fridge, hence converting hot to cold, by itself.

Caravan Battery Power Saving Tips

Over time one thing I found about the battery is that a certain amount of consumption can drain the battery too fast, forcing me to turn off more appliances as it gets darker. When the rate of depletion is too high, it drains the batteries faster than some comfortable discharge rate, and the metre starts dropping to a dangerously low level. When I have only my laptop plugged in, my two 240 Amh batteries seem to last without a problem until morning, unless it gets too cold in the caravan truck. But even when only using the laptop I find I can tweak its use to squeeze out more battery power:

one of the best things you can probably do is to get a Juice (or similar) adaptor. If you have one but lack the necessary adapter for some of your devices, you can make your own Igo juice70 adapter (just make sure the ampere and voltage requirements are within the adapter's abilities if using some electrical devise not found on their website - compare against the other power levels the adapter can handle). This is a smart and universal adaptor that can switch automatically and intelligently according to whatever you plug it into. The input source can be 120 or 240V, but it can also be 12 or 24V. You just need to buy the right adaptor plugs and then you can plug it straight into your laptop, or any other appliance (made for planes as well, or plugging into your cigarette lighter). It is mostly designed for laptops, but I assume it can be used for other appliances. Just check out their website. This way, I can plug it straight from the regulator, which feeds 12V of current with a protection fuse, into the Juice adaptor, and out comes the 16V or whatever is necessary for my laptop. In this way you lose the minimum amount of energy. Otherwise, if you convert the 12V to 120 or 240V using an inverter, and then convert it back down to 16V using your regular wall plug laptop adaptor, you are apparently losing about 15% of the energy at each conversion process;

turning down the brightness and contrast of your laptop screen can make a difference;

Using Less Power on Your Laptop

amazingly, I've heard the inverter work harder whenever doing some computer tasks requiring higher process speed. So even high CPU usage and playing heavy duty computer games or watching action movies can make a difference;

if watching movies, copying them first to your hard drive (if you have enough room) will save energy, instead of using the CD or DVD rom for the duration of the film;

remove the battery from the laptop so that energy is not wasted trying to keep it at 100% charged. DEFINITELY remove it if the battery is below charge, especially at low levels, like near 0%. When I plug in a zero% charged battery into the laptop, I can hear the inverter go berserk until the charge is up to around 20%. So make sure to save all your charging for when the sun is out. The more intense the sun, the more batteries you can charge. Even a small mobile battery can suck up a lot of juice. When the sky is partly cloudy, I'll find myself turning on and off different chargers and keeping a close eye on the regulator and how the sun looks outside. Towards the end of the sunny day, stop recharging and make sure to give your main batteries time to charge up to full, before darkness hits;

My laptop shows the charging activity (if yours doesn't perhaps you could find a useful program on the internet). At the bottom in the system tray you can see the light green 99%, which shows how fully the battery has been charged. But when I click for more battery details, I see that it is not being charged ("Battery - No Activity"). In this case I can dare to leave in the battery at night. I like to keep in the battery whenever possible because sometimes the regulator resets when there is a lot of sun, or automatically shuts down when the caravan battery strength gets too low, in which case my laptop turns off and I lose a lot of my offline work and have to restart the computer, which can be pretty annoying.

when watching movies, better to use earphones than the laptop's loudspeakers. When I moved out of my house, since I didn't get an attractive offer for my alarm system, I gave it to charity but 'stole' the 12V mini rechargeable battery. I now use that to power my 12V computer speakers. Can grab that with my mp3 player and hit the beach when I want, or I can use it for movies when several people will be watching;

when not using them disable all wireless devices, such as infrared or wifi. When these are enabled your computer is constantly looking for a signal, which draws energy. Even more so if you are out of signal, like a mobile phone working harder and draining the battery faster when the signal is low or weak. To disable these, simply go to Start > Control Panel > System (or right mouse click on My Computer and press Properties) > press the Hardware tab, then the Device Manager button. Alternatively you can go to Start > Programs > Administrative Tools > Computer Management, where you will also find the Device Manager. In there you might open up Infrared Devices (press on the + to the left, or double click), right mouse click on your infrared device and press Disable. When you want to use it later, simply go through the same procedure and select Enable. You can do the same with your wireless connection, which you should find among the Network Adapters in the Device Manager. It might have "Wireless LAN" written in the name. If you are not sure which of your network adaptors is your wireless/wifi one, you can also try going to Start > Control Panel > double click on Network Connections. In the same manner, choose your wireless connection with your right mouse button and press Disable or Enable. When my wireless network card is enabled and looking for a signal, a little green light appears on the frame of my monitor, indicating to me that it is on. Perhaps you have a similar indicator. Generally, whenever using my wireless connection, I always Disable it once I'm done, as a standard practice, to help save battery power for whenever I might need it later. You can find more suggestions how to properly manage your computer on my computer tips pages;

Other Tips for Saving Energy in the Caravan

I discovered that long extension cords can leak energy, so try to keep your cables on the shorter end. Also, be careful of overcomplicated power splitters (or whatever they're called - basically those knobby things which turn one socket into three etc.). Better to use a quality but short extension chords with many outlets, preferably also with its own fuse. I've almost felt shocks with the splitter things, and power can leak through the floor etc. Remember that the minus end of your electrical circuit may or should be grounded to the metal frame of the vehicle, so you want to make sure that the plus is always well insulated - to prevent inefficient drain, or even worst, electrocution. Once my laptop adaptor cable was strewn across my belly while working, and I felt a current go through my hand when I touched one of the caravan truck's stereo speakers. So be careful!

Extending the Life of Your Caravan Battery

When surviving on the road like me, especially if your work and life depends on it, your battery can become the heart and one of the most important devices in your caravan. And like anything this important, you want to know how to take care of it well, so that it lasts long, and so that it works well. Different batteries work in different ways, and hence need to be taken care of differently. A normal car battery should always stay close to 100% fully charged. Dropping too low could seriously damage the battery, which is basically comprised of acid and some plates. If the voltage drops too low, chemicals within the acid crystallise and form onto the plate, reducing the efficiency and quality of the batter. If the liquid level drops too low and exposes some of the plates, crystallisation will form on the plate surface exposed to the air, and once again damage the battery.

You should keep some distilled water for this purpose (not expensive and you should be able to buy it at every gas station) in case the liquid level ever drops too low. There are ways to specifically test the acid, or possibly refurbish the battery, but while traveling (in Eastern Europe and the Middle East) I found no one knew what the heck I was talking about, so you may be on your own. You could try ordering a kit from one of the weblinks provided below. Or hunt around for some laboratory which could help you. Otherwise, there are some simple tips to follow.

Research carefully before buying a caravan battery. The kind used for golf carts are supposed to be the best, but perhaps more expensive.
You may need to unscrew the caps from time to time and check the liquid level. Make sure the plates inside are never exposed inside.
ALWAYS wear safety glasses when dealing with batteries. Even normal glasses. They might explode one day and you will be blind for the rest of your life, regretting that you didn't bother with this small precaution. I prefer to be highly paranoid.
Make sure the caps are always screwed on tight. You don't want to be inhaling this gas. It may be flammable too. If it explodes next to your big propane cooking tank, someone may spend a longer period of time scraping the mess, including your blood and parts, off the fine interior carpentry. If possible, hang the batteries under the truck in a concealed and protected chamber.
When it is charging you should see some bubbling action in the water. If not and your battery is having problems charging to full capacity or drains quickly, chances are that one of the chambers are dead, severely dragging down the capacity of the other chambers. You might be able to revive the chamber by going to a special laboratory or by following the links below, or you may just have to buy another battery.
When charging with your regulator, make sure to always charge similar strength batteries. Don't hook up in parallel several 12V batteries, some of which have significantly different Amh capacities. I was told this was bad, and confirmed it when my regulator got all screwed up trying to charge my strange connection. It's not good to have a strong battery hooked up to a weak one either. The deadish chambers will drag down all the other chambers in the series, and kill the healthy batter faster.
In extremely cold temperatures, keep in mind that the battery dies faster. The bubbling chemical reactions like it when it is nice and warm. Avoid draining it too low in such cold temperatures. If left unattended for a longer period of time, make sure it is left at around 60% charged, or according to the factory instructions. For very long periods, keep it at the recommended charge level and indoors somewhere, in the warmth.
If leaving it unattended for a longer period, be aware of parasitic drains, such as car clocks or alarms. Better to just unplug it outright to make sure. Get a cheap voltage meter and test the strength if not using it for a longer time. Charge it up to the ideal level if it gets too low.
Obviously you want to be careful about poking holes into it and watch out for leaking battery acid (seal the case with glue if needed, add distilled water to the chambers if necessary). Keep it flat and horizontal.

Here is some info I found on the net. Seemed rather complicated, but perhaps you might find it useful. Links one, two, three and four.

Protecting the Caravan's Electronics Against Lightning

During a few fiery lightning storms it occurred to me that I was sitting duck all by my lonesome parked on the beach in the middle of nowhere, the only piece of metal for miles around. Considering all the insulation around me I myself felt safe but I was worried about my electronics. For this reason I decided to get switches for all the wiring, such as the ground to my stereo or from the solar panels to the regulator. Basically at every connection where the lightning could fry my electronics. Might as well get some sort of fusebox switch system and I'll ask the salesman about this at the electrical parts shop.
I also thought it might be a good idea, during major storms, to lean some thick metal rod outside against the side of the truck and the ground, to help ground any lightning. Or perhaps you could think of getting a lightning rod. I still have to research this. But so far, I asked my dad and he seemed to give me some good advice:

I don't suppose there is much you could do in case of a direct hit, which may very well fry all your caravan electronics including some of the wiring. You personally should be relatively safe inside your 'Faraday cage' (as long as you exit and enter with care as noted below). On the other hand, I don't see why the Big Guy would want to hit you by lightning, unless you do something silly, like park on top of a bare hill.
There is a much bigger chance of a secondary discharge. When the charge in a cloud reaches a potential sufficient to attract an opposite charge from the ground and punch an ionized conductive channel through the air, it will discharge by electricity rushing up and down a few times: crack crack crack, this motion of electrons at the same time inducing charge in surrounding objects. Once I was gathering firewood at Mnichovice, when it started thundering. I rushed in through a back metal gate and as soon as I closed it and stepped away: caboom, lightning hit somewhere and there was a horizontal discharge between the gate and a tree little over a meter away. Considering that air breaks down at about a thousand volts per millimeter, you can see that secondary discharges can pack a punch of their own.
The other thing to keep in mind is that, when lightning hits the ground, a potential may appear between two different points on the ground, as the charge is dissipating (by conducting away from the hit). That is why it's advisable not to stand with feet apart in a thunder and when walking, only make small steps. Rubber wheels will protect the caravan truck against potentials caused by such ground currents. For the same reason, if you choose to ground it, should be only in one place (preferably close to where you get on and off). A metal rod leaning against the body is not much of a ground; if you plan to stay longer in one place, you could run the rod in the ground and connect it with a hefty wire to the chassis.
I am not sure about disconnecting the battery ground: if your electronics is grounded to the chassis elsewhere, it might make no difference from a lightning point of view but might be a good general precaution against shorts and leaks, as you mention. If however your equipment is actually grounded solely through the battery's ground, disconnecting it might deprive it of a degree of protection in case of lightning.
If your caravan truck stands on rubber wheels and is not grounded, you should be careful getting in and out, as an electrical potential may develop between the body and the ground especially in case of lightning. You should jump down rather than stepping down while holding on or having one foot on the truck. To get on, you can lean your metal rod against the caravan truck at the point of entry before touching the body.

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