Articles - Electronics: S-CAB


This page covers my information about using a small battery to power a scale locomotive, controlled via a radio-frequency-based throttle.

In the late 1800s and early 1900s, model railway locomotives were powered by a clockwork wind-up mechanism. Later, using electricity and a transformer, modelers could power their locomotive by applying the transformer's output to the track. A knob of some kind on the transformer controlled how much voltage was applied to the rail, and therefore controlled the speed of the locomotive. The big disadvantage was when you wanted to run more than one locomotive, because both were controlled by the same track voltage. The only way to control two or more engines independently was by breaking the layout up into electrical blocks, where each block was controlled by a separate transformer, thus allowing the operator to run the train in one block separately from a train in another block. Wiring was complex, and the operator felt more like he/she was operating the layout, rather than the trains.

In the 1960s, thanks to the invention and commonly-available transistor, "Command Control" or "Carrier Control" was created. The idea is to embed a signal into the track power, and each signal is uniquely received by only one engine. Many independent and proprietary systems were invented and sold into the late 1970s.

In the early 1990s, the modernday DCC system was standardized by the NMRA, allowing the modeler to pick and choose components to fit their system, controlling his/her engine independently.

However, regardless of which system you use to control your locomotives, the fundamental fact remains that they must pick up electricity from the rails upon which they run (two-rail or three-rail systems). Some systems use radio frequency to control the behavior of the locomotive, but, still, the engine picks up its power from the rails. Can your trains do this?...

Why Radio Frequency?

To be able to control a specific locomotive on your layout, you must be able to communicate with it and single it out from the rest of the engines on your layout. Modernday control systems use an embedded signal in the electricity sent via the rails to the engines. All engines receive the same electricity and signals, but a small printed-circuit board in the locomotive can be programmed to ignore all the signals except the one intended for its use. This board is called a decoder, because it "decodes" the signal from the track and only processes that which is intended for its use. A decoder is assigned an "address" (much like your house is assigned a street address, so that the mail man can deliver mail only intended for you). This address is typically a number. Most decoders are pre-programmed with the default value of "3", but that number can be easily changed. Most modelers will use the number on the engine as the address, or use the last two digits of that number.

The advent of radio frequency communications allows for signals intended for a specific locomotive to be sent through the air to the decoder in the locomotive. To be able to receive that signal, the locomotive must be equipped with an additional printed-circuit board called a "receiver". If the control signal is sent via the rails, such a board is not needed. However, to start the process of moving away from getting information from the rails, the receiver is necessary. This works in the same way that a television's remote control works. It sends your command from the remote control through the air to a receiver built into the television, which then interprets the signal/command and does the appropriate thing. Television remote controls use infrared signals to communicate with the television (which requires line-of-sight), but for model railroading that can be impractical, so we use radio-frequency communication, which does not require that you aim the throttle at the engine you are controlling. Infrared is cheaper and easier to manufacture, but you can imagine if your locomotive is inside of a tunnel and you need to stop it quickly; line-of-sight will not work in a tunnel; radio-frequency will.

So, radio-frequency-based communication will remove the need to embed the control signal in the rail, and you can hold the throttle any way you want to. There is an upper limit to the distance such a signal can be communicated to the engine, and materials such as metal can interfere with the signal. However, most people nowadays walk with their locomotives as they operate their layout, so that is not a problem. Even if you prefer a central control panel, the distance is usually well within the size of most home layouts.

Why Battery Power?

As described above, regardless of which control system you may have used in the past or are currently using, they all rely on getting the electricity, used to move the locomotive, from the rails. If the rails, the wheels, or the contact strip inside the locomotive are dirty or corroded, electricity will not flow. If a piece of rail doesn't have a wire or a rail joiner connected to it to send it the electricity, or if the wire has eventually worked itself loose, this can also lead to electrical-continuity problems. Either way, the engine will stammer or stop. If the locomotive has enough momentum, it might, mechanically, move itself past a dirty spot on the track and thus be able to pick up the electricity again to keep running. In the past this was acceptable, however, with today's DCC and sound-equipped locomotives, it is very noticeable, in that the locomotive's sound all of a sudden stops and starts over again. Very annoying. Lately, companies have been coming out with an extra part or circuit board that you can install that will store some electricity to keep the system "on" when such a power loss occurs. A "super capacitor" or a "stay-alive" circuit board will help.

However, if you have your locomotive completely powered by a rechargeable battery, none of that will be needed, and the cleanliness of your layout's track or your locomotive's wheels is of little or no concern. Due to the size of battery needed to power model locomotives, this technology was first implemented in the large garden-gauge locomotives. However, with the advent of small cell phones, and the continuous improvement and miniaturization of cell phones, batteries have gotten smaller and more powerful over the years. They can now be easily installed in O-, S-, HO-, and even some N-scale locomotives.

If you can imagine your locomotive carrying its own supply of electricity, you can visualize your layout without the need for complicated wiring for such special track work as turnouts, crossings, reversing loops, and turntables. Depending on your needs, you might even be able to go as far as not having any electricity hooked up to your track work at all! Imagine the time you can save by completely skipping, or significantly simplifying, the wiring phase of your layout's construction!

Who Makes Battery-Powered Systems?

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Battery-powered locomotives are somewhat new. The garden-gauge world has had them for a while, but the components they use are far too large to be used in the smaller modeling scales. The deciding factor is the amount of current the locomotive needs to do all of its tasks versus the size of the electronic components needed to handle such current. G-scale locomotives measure their power draw in many amps, while the smaller scales, such as S-, HO-, and N-scale measure theirs in terms of milli-amps. Older S-scale (such as American Flyer) and O-scale engines kind of fall in between, and their needs will typically need to be weighed on a case-by-case basis. Sometimes the solution is to replace the motor with a modern, more efficient one before installing the battery-powered system of choice. Sometimes a more powerful decoder is necessary.

Here, I wish to capture some basic information about the various control systems that are currently available within which a battery-powered solution can be used. They are described in alphabetical order. See links above, right for their web sites. The Stanton S-CAB system will be described separately, since that is what I use.

This company makes components that allow you to control your locomotive via Bluetooth communication (typically using your smart phone or tablet). Because that system doesn't use the rails to communicate information, having it powered by a battery within the locomotive is a distinct possibility. It requires a custom solution, and it is my understanding that the battery cannot be charged via the rails, unless one makes a custom installation. They currently do not support sound yet. Their User Showcase page shows various installations done by people who have bought their system.

Crest Electronics
Those who model in any of the large-scale gauges will likely be familiar with this name. It was created by AristoCraft/Polk. AristoCraft spun off this division as a separate company, and then later, itself, went out of business. However, in July 2016, the owner of Crest (I believe he is the son of the owner of AristoCraft) announced that he could not continue the company and is closing it down, only servicing existing equipment.

CVP Products
CVP Products makes a system for the large-scale community, called the AirWire system. For the smaller scales they introduced the microAirWire system in 2016, which can output up to 1.5 amps (5A surge). All their decoders are DCC-compliant. They have two throttles that can be used to control all of these AirWire systems. The T5000 PRO throttle is also a complete and self-contained decoder programmer. I do not see where their system would allow charging from the track (a feature not needed in G-gauge railroading), so you may need to provide an externally-accessible plug to hook up to an appropriate battery charger, or be able to remove the battery from the locomotive when it is time to recharge.

DelTang is a more conventional radio-control (R/C) solution, based in England, which may be more appropriate for European customers. It seems to work for smaller scales, but it does seem to require a bit more electronics knowledge to install the system. It doesn't directly support sound decoders, and is not DCC-compliant. Remember that with radio-broadcast signals, the manufacturers have to have their systems certified for use within a country. So be sure to check that for the system in which you are interested. It is my understanding that the DelTang system can be used in the U.S., but it cannot be sold by a dealer in the U.S. (you would have to buy it directly from a British dealer and have him/her send it to you in the U.S.). My impression from studying their web site is that the system requires quite a bit of tinkering, and does not support charging the batteries from the track. You must provide your own batteries and an appropriate charger. By the way, there is an excellent web site about the DelTang system, The On30 Guy. Much like this page, he also compares the various battery-power systems available. I highly recommend that you read through his site, if you are interested in this technology. Contact fellow S-scaler Bob South, if you want to seriously pursue the DelTang system (he can help with advice and custom installations of the DelTang systems and any other brand of battery power radio-control system in plastic, metal, and brass locomotives). Miles Hale recently did a show (subscription-based), where he showed how he installed a DelTang chip in a small On3 engine (Miles uses S-CAB on his personal layout - see this episode where he introduces S-CAB).

I only recently (May 2017) found out about this British company. They provide a battery-powered solution that uses a radio-frequency controller. It looks like an interesting system that is designed for OO-scale, which means it might work in S-scale and some smaller O-scale locomotives in the U.S. It requires the installation of a plug board, so that an external charger can be hooked up to re-charge the internal battery.

The RailPro system, by Ring Engineering, uses radio-frequency control, but their system doesn't provide battery power. There is a YouTube video of someone who converted an HO-scale engine to battery power (note his disclaimer in the comments section).

Tam Valley Depot
Update October 2017: Tam Valley Depot announces that they will no longer be producing their dead-rail system. Tam Valley Depot's solution takes a bit of a different approach. It ties into your existing DCC system. It takes the existing system's DCC signal, broadcasts it into the air, which is then received by the locomotive, where both the engine and the receiver/decoder can, optionally, be powered by battery. You control your engine via your existing DCC system's throttle (in 2017 the company introduced their own throttle). This eliminates the dirty track issue, but it does require that you have an existing DCC system. The batteries are lithium-polymer, and the system doesn't support charging the battery from within the engine from the track (battery removal, or external plug is required). If you are starting from scratch, this is an expensive solution, because you have to first buy a DCC system and then buy their components and batteries. Apparently a CVP T5000 can be used directly with the system, by-passing the DCC system, if you don't have an existing DCC system. Either way, it is a viable alternative to the other systems listed here, especially if you already have an existing DCC system, and plan to keep it.
There is also the Dead Rail Society web site. It has quite a bit of information. However, be aware that it is sponsored by Tam Valley Depot, so it is biased toward their solution.

Conventional R/C
When I started searching for a battery-power solution in 2012, I only knew of the Crest system (for garden scales), and custom radio-control solutions. If you search the Internet, you will find some people who have adapted the conventional airplane/helicopter/automobile R/C system for use with model trains. They require a substantial amount of creative and custom work. If you enjoy that kind of work, this would work for trains, but I find the conventional R/C control system way too bulky for indoor train-control usage, and the left/right controls are of no use in this scenario. Might be fun for the electronics tinkerer, but any of the systems mentioned on this page are superior, in my opinion.

What is S-CAB?

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The one system not mentioned above is Neil Stanton's S-CAB. This is because that is the system that I ultimately chose in 2012, and I am very happy with it. This is the one that I have actual experience with, and that I will cover in the rest of this page. I have no financial ties to S-CAB, other than being a satisfied customer. At the time I purchased my S-CAB, I had been using Digitrax' DCC system for about 13 years, both at home and at the clubs I belonged to. In the end, I completely gave up on the Digitrax system.

Fundamentally, S-CAB is a radio-frequency train control system. The throttle sends your commands to the receiver in the locomotive. This removes the train-control signals from the rail, thereby making communication easier and better. Secondly, once Neil built that system, he continued and incorporated the ability to power all of the electronics within a locomotive from a rechargeable cell-phone-sized battery. The battery-power system is separate from the core S-CAB system. However, I bought both the S-CAB and the battery-power components, since the latter was really what I was after. The beauty of Neil's S-CAB system is that it is a completely self-contained system. It includes components to safely charge the battery from any electricity detected on the rails, and it safely shuts down the system when the battery has reached its drained state. This allows you to let the engine charge via a piece of powered track, and let it sit overnight without any worries.

Up until June 2013 you could only buy the system and its components via North West Short Line (NWSL). However, Neil has now taken over the sale and distribution of the components himself. Go to the S-CAB web site (link above right) to view all of the options, and to purchase your system and additional components. Neil does a good job of keeping the site updated, and he posts blogs every once in a while to show you an interesting installation. The web site has all the latest info, so always go by what it says, not necessarily by what you read here, although I try to keep this page updated. If you are in Australia, Berg's Hobbies is an authorized retailer of the S-CAB system there. I included the Podcast links above so that you can hear a bit about Neil's history and how he got involved in partnering with NWSL, and about why and how he designed the S-CAB system.

How Does S-CAB Work?

The S-CAB throttle sends your commands to the receiver circuit board installed in your locomotive. That board then converts the commands into the standard DCC commands that the DCC decoder installed in your locomotive can understand. The DCC decoder then interacts with the various parts in your locomotive to execute the command that you gave it (turn on the lights, move forward, go faster, etc.). This communication between the throttle and the receiver board is done via radio-frequency, so you do not need to aim the throttle at the locomotive.

If you have the battery-power components installed, the electricity comes from the battery. The decoder is powered by the battery installed in the locomotive. The decoder then sends that electricity to the motor, LEDs, and speakers (if so equipment) to power those parts. The decoder is always powered from the battery, even if your locomotive is running on track that has power applied to it. Update: in 2017 Neil released a new version of the BPS board that allows it to pick-up power from the rail if the battery is discharged, so that you can keep running your engine even if the battery is empty (great for train shows!).

You can run on track that has no power (i.e. "dead-rail"), or that has AC, DC, or DCC applied to it. Inside the locomotive is an extra circuit board called the Battery Power Supply (BPS) that is in charge of charging the battery, shutting the battery power down, and upconverting the voltage of the typical cell-phone batteries (most supply around 3.7 volts, but our locomotives need around 12 volts). This extra board does add one more thing that you have to fit within your locomotive, but the peace of mind that it provides is well worth it. Combined with a small circuit board that is attached to the top edge of the battery, the BPS prevents the battery from being overcharged (which would cause the battery to explode), or to drain too much (which would prevent the battery from ever being able to hold a charge again). It also manages the various states of charging and not charging the battery depending on whether or not your locomotive is running on dead rail, is equipped with power pick-up connections, or is running on powered track.

So, with the radio-frequency control and with the battery for power, a locomotive is able to run on unpowered track. All you need are the components inside the locomotive and the throttle. No other components are needed.

Turning It On and Off

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Battery power should normally be turned off when you are not using your locomotive (e.g. at the end of an operating session). The battery can hold its power for many months (my personal experience). If you have completely dead rail, you need to wave a magnet over the reed switch that is installed in the BPS circuit board (you usually mount that board near the top or side of the engine, so that it is within 1/2" of where the magnet can trigger it). If you have track power, the BPS in the engine will automatically turn it on, as soon as at least 6 volts of AC, DC, or DCC power is detected. Even a 9-volt battery briefly touched to the rails will turn the unit on.

To turn off the battery power, first remove all power from the rails that the locomotive sits on (if applicable), and then turn off the battery power via the BPS. Originally, the BPS came with a physical push button switch that you had to mount somewhere to turn the power off. With the Soundtraxx Tsunami decoder, pressing F5 on the throttle turned the power off. With the new NCE "Dead Rail" decoder, that same functionality is now available for non-sound decoders. Personally, since I have an older version of the NCE decoder, I have simply installed a second reed switch (identical to those on the BPS board; see link above, right) that I wave the magnet over to turn off the power to the battery. Update: the latest version of the BPS board now includes both the on and off reed switches built into the board, for that very same purpose. See the photo below, courtesy of S-CAB.

What are S-CAB's Limitations?

Neil's S-CAB system was designed for those people who are still running their layouts with analog/DC power. Surveys show that that is still a majority of model railroaders, despite the inroads that DCC has made. DCC is not cheap, and it is definitely not intuitive to use or "debug". The S-CAB system is the simplest system that I have ever used. Here's my typical scenario, from making the decision in my mind to run one of my trains:

1. Turn on the S-CAB throttle (small switch on the left side of the throttle).
2. On the locomotive, wave the magnet wand (see photo above) over the reed switch.
3. Move the speed slider on the throttle to move the locomotive.

We are literally talking 5 seconds here from deciding to run an engine to actually running it. No other system can do that from a totally "off" state!

However, the S-CAB system is not perfect and does have some limitations (on purpose). It is up to you to decide whether these limitations are deal-breakers for you.

1. It only supports two-digit addresses (most DCC systems can use 4-digit addresses).
2. Multiple-unit consisting is not directly support.
3. Programming is easy, but the throttle only supports a handful of CVs (more on this further below).
4. Throttle doesn't remember the previous engine's settings (controls are mechanical).
5. The throttle can only talk to the receiver, but the receiver cannot communicate back to the throttle.
6. There are only 28 speed steps.
7. There is no support for accessory decoders.
8. Detection for controlling layout signalling is not directly supported (applies to all battery-powered systems).

With a bit of creativity, there are solutions for each of these:

1. I use the last two digits of the locomotive's engine number as the programmed address.
2. I don't do MU, but if I did, I would use the same address and use the same type of locomotives to consist.
3. I have been able to get satisfactory results with just the CVs that it supports for programming.
4. It is easy to switch between engines, but when you do, you just have to play with the physical controls on the throttle to adjust the engine that you are switching to; all it takes is a bit of practice to get used to it.
5. The only time bi-directional communication comes in handy is when programming the decoder; there is no way to read-back what the decoder is programmed to, so you either re-program the value, or you write it down in a journal or a software application.
6. I have found the 28- vs. 120-speed-steps to not be an issue in real-world practice.
7. I had to come up with a different way of controlling my turnouts, but it turned out to not be that big of a deal.
8. For signalling, I am thinking about using infrared detection circuits embedded in the layout (but currently I have no need for that feature).

As of September 2017, Neil now has his BPS boards being able to produce up to 1 amp of power. For large power demands, such as with larger O-scale engines, Neil offers 4- and 8-amp receiver/decoders that will work with the radio frequency communication, but require custom battery power installation. These need to be series-connected larger batteries, such as LiPo (3S or 4S), with an external charger.

S-CAB Throttle

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The throttle feels good in my hand. Where my thumb is in the photo are two small slide switches. The bottom one (not visible) turns the throttle on and off. The upper one (visible) switches between normal mode and CV-programming mode. Either state is indicated by the LEDs to the left of the main two-digit display. Below the display is a slide switch to control the locomotive's direction. To the right of the display is a long slider that is used to control the locomotive's speed.

The push-button section of the throttle can be used to select a different locomotive, control the speed via the push-buttons (the mechanical slider doesn't adjust, of course), turn on and off decoder's features (lights, bells, horns, etc.), do an emergency stop, and select and program the programmable CVs.

By the base of my thumb is a USB port. That is used to connect the throttle to a computer port that can be used to charge the rechargeable battery that is inside the throttle. I charge mine each time I pack up my equipment for taking it to a local train show, so maybe 4 to 6 times per year. I have never had the throttle "die" on me!

S-CAB Components

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As stated above, the core S-CAB system consists of the throttle, which sends commands, and the receiver, which receives those commands. The receiver then converts that information to where the standard DCC decoder can understand it. Because the receiver and the decoder are so closely related, they are hard-wired to each other, as is shown in the photo. The one I used for my installs was the NCE D13SR non-sound decoder. The newer NCE D13DRJ "Dead Rail" decoder actually merges these two boards into one. The wires coming out of the combo are the standard DCC wires coming out of any non-sound decoder.

S-CAB Battery Components

For the S-CAB battery-powered option, you get the BPS board (Battery Power Supply) shown on the right, and a battery. The white plug on the battery plugs into the white socket on the BPS board. Again, this is showing the older versions I got back in 2012. The BPS I got puts out 500mA, but the newer version that is currently produced is smaller and puts out 1 amp. The battery shown here is rated for 1,000mAh of storage (i.e. it can provide 1-amp of power for one hour, ideally). Theoretically, you could buy your own batteries, but they will not have the protection that you need to protect your engines from battery damage. It is simply not worth the risk to your engine, your layout, or your house (!) to save a few dollars. I strongly recommend that you buy your batteries from Neil only; they aren't expensive. He thoroughly tests them before making them available to us.
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This photo shows an 850mAh battery that is skinnier, but longer. Great for fitting in skinny diesels. Again, this is an older battery, so be sure to check Neil's web site for the latest batteries he has tested. There is a small electronic circuit at the ends of the batteries which help to protect the battery from being damaged.
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If you have the space in your locomotive, I would highly recommend doubling-up on the batteries. The more batteries and the larger they are, the longer you can run your engine. This photo shows two 1,000mAh batteries connected in parallel for a theoretical maximum of 2 amps for one hour (or 1 amp for 2 hours, or 500mA for 4 hours, etc.). As with the above, this is an older battery shown in the photo, but it shows what is possible.
Briefly, if you are not familiar with the rating used on rechargeable batteries, the units are "Ah" or "mAh". This means Amperes per Hour or milli-Amperes per Hour. The rating indicates the amount of current the battery can consistently output for one hour of use. Those are theoretical numbers, because it depends on how fully charged the battery was, and the age of the battery. So, when you have an 850mAh battery, it means that it can output 850mA for an hour. So, if your locomotive needs 850mA to do its work, then you will get about an hour's worth of running time out of that battery. However, in the real world, small-scale locomotives use a lot less than that. Also, you don't run your locomotives with the same speed continuously. You vary the speed, and sometimes the engines are sitting still for a little while. Other things that drain the battery more quickly are the speakers of sound-equipped engines, the length and drag of the train the engine is pulling, grades, and to a lesser extent the LEDs for the lights. The locomotive's motor and internal gearing will also have an impact on the duration of the battery's charge. It is always best to have a modernday efficient motor in the engine, and to make sure the gearing is clean and correctly lubricated. But, despite all of these considerations, you always want to try to fit the largest battery you can into your locomotive, and try to double them up, if possible.

How to Install the Components

This diagram is my attempt at showing how all the S-CAB components are to be connected. If you have, or could potentially have track power, you can use the locomotives track power pick-up method for connecting to the BPS. This would allow the BPS to charge the battery whenever it detects 6 volts or more of AC, DC, or DCC power. The DCC decoder is powered by the battery via the BPS (note: the latest version of the BPS allows for bypassing the battery and having the locomotive be powered by available track power whenever the battery runs empty). The DCC decoder then controls the motor, lights, and sounds, as normal. I have fully documented the installation of the S-CAB with battery power in my three engines:
S-scale NW2
S-scale FA-2
S-scale RS-1

If you do not feel comfortable doing your own electronics installations in your locomotives, there are people who can do it for you, for a fee. My recommendation is to first contact Neil Stanton. If he doesn't have the time to do it, he will be able to refer you to someone who is qualified to do it. However, if you have ever installed a DCC decoder yourself, especially a hard-wired one (as opposed to a simple plug-n-play one), this is only slightly more challenging. It is not so much the wiring (which is well-documented), but rather the fitting of the components. As you can see from my own installations above, a little creativity goes a long way.

How Does This Impact Layout Construction?

So, let's assume that you have one or more engines equipped with the S-CAB battery power system. How will they function on a layout? If you already have an existing, wired layout, there is nothing that you need to do. Your S-CAB, battery-powered engines will run just fine on your layout. If you have the BPS wired to the locomotive's pick-ups, it will be automatically charging the batteries for as long as the layout is powered. A number of people who have fully-functional existing layouts generally converted some of the more "stubborn" locomotives to battery power, such as short wheelbase diesels or steam engines such as 0-4-0 and 0-6-0. Especially if they are used as slow-moving yard switchers that tend to stall on turnout frogs, these are great candidates.

If you are getting ready to build your layout or have already started, but you haven't made it to the wiring phase yet, you might want to entertain going "dead rail". Not having any wiring to do is a big time saver. However, you will need to consider these three things. First, how are you going to recharge the engines' batteries? You might want to have a piece of track in a yard that is connected to a 12-volt power supply. At the end of the operating session, you could run the engine to that piece of track and let it charge overnight (it typically takes 8 hours to fully charge the battery). Second, you may need to consider future visiting equipment. If you want to have friends bring over their equipment, you will need to think about how they have their locomotives equipped. Note that the reverse situation, you taking your S-CAB equipped engine over to your friend's layout, is not a problem at all. The engine will run just fine on a DC-, DCC-, or even AC-powered layout. Third, are you planning any automated signalling on your layout? If so, you will need some sort of detection system other than current-drain to detect the presence of a battery-powered train on a section of track.

Others choose to wire only the main line of the layout. That way the engines are recharging while they are running, but you can skip wiring turnout and crossing frogs, reverse loops, turntables, and sidings.

I am currently building a large diorama layout that has absolutely no track wiring in it at all. Completely dead rail!

How to Charge the Battery?

The S-CAB batteries, if fully drained, need about 8 hours to fully recharge. Charging time for these types of batteries is not a linear curve. The batteries charge quickly at first, but then slow down as they get closer to being full. So, if you are in need of the engine but its battery has completely drained, you can charge it for 2 hours, and then use it again (with limited duration). However, to be sure the battery is fully charged, 8 hours is needed. In my typical scenario, I let my engines recharge overnight.

My layout is completely dead-rail. So, I pick up my engine and place it on a piece of flextrack which has a 13.7-volt power supply hooked-up to it (see photo). I have a spare Radio Shack power supply (used for testing or charging automotive components or batteries), to which I connect two alligator clip-equipped wires to a piece of flex track. I made it fancy by buying and connecting an LED read-out display that shows the voltage on the line. But that's it. Just turn it on, and let it sit for 8+ hours. After turning the power on, I use my throttle to change the headlight LED of the engine, which helps me to verify that the wheels are indeed picking up power from the power supply (at this point in time you do have to worry about dirty wheels/dirty track issues, of course). I then leave the headlight on to remind me that the engine is being charged. For two-day train shows, I usually run my American Model FA-2, which is shown in the photo. It runs all day. I then take it home at the end of the day, and let it charge overnight. The next day I bring it back to the show and it runs the entire day again. When I come home from the show, I recharge it again overnight. I usually recharge all of my engines when I do this, even those that I don't bring to the train show.

On my previous layout, I had a section of track set aside that was connected to this power supply underneath. I simply drove the engine onto the track and turned on the power supply to let it charge overnight.

If you are constructing a layout, you could connect a 12-volt power supply to the tracks in a staging yard, so that at the end of an operating session when your engines are in the yard, you could turn on the power supply and let them all charge overnight. I believe the BPS requires about 200mA per engine to charge the battery. So, if you have five battery-equipped engines, you'll need at least a 1A power supply for this.

As stated before, if you have an existing layout that has track power, the engine will be charging the batteries as long as there is power to the rails. If you ran your engine extensively near the end of the operating session and you then turn off your layout's track power, your battery may not be fully charged. So, in that case, you may wish to leave your layout's track power on for while.

How to Program the Decoder?

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Programming the NCE decoder/receiver that I bought for my engines is just about as trivial as can be. The quick-start manual that comes with the system has clear and simple instructions for how to do that. Since the system only uses two-digit addresses, I program my decoders to use the last two digits of the road number. I was able to get my NW2 switcher to run nice and slow programming the CVs with the throttle. One of the things I learned, though, is that engines respond differently to pure DC. In all cases they run more smoothly. However, some engines may need some extra work. In the case of my RS-1, I had to really work with all the CVs to get something reasonable. In the case of my FA-2, I had to replace the motor with a better-quality one.

One really neat feature I like about the S-CAB system, is that you can set it up such that a particular locomotive address is always the default one when you turn the throttle on. I use my NW2 switcher on my home layout most of the time. Its last two digits are "12", so I have the throttle set to default to 12, which allows me to run the switcher right away. Another nice operational feature is that if you have two engines (or more, up to 15) that you are operating, once the address has been punched in, you can switch between the various engines simply by pressing the "Loco#" button. Each press cycles through the list of already-punched-in addresses. Of course, when you turn the throttle off, those numbers are "forgotten".

If you desire more control over programming the CVs, if you want to program the CVs of a sound decoder, or if you want to be able to read back the CVs of a decoder, then you are going to need another piece of equipment. Neil sells the RAPA board (see link above, right). He has only tested it with the NCE PowerCAB controller, but it might work with a Digitrax or other DCC system as well (e-mail him or contact others who have tried this approach, first).

If you don't have an appropriate controller (such as the NCE PowerCAB) or none of your friends do, there is another solution to fully program the CVs of your engine's decoder. The CVP T5000 throttle. You might consider this your "power-user" throttle, while the S-CAB throttle would be a great operating-session/guess-operator throttle. The CVP T5000 throttle uses the exact same transmitter and receiver chips as the S-CAB system does, so that throttle can communicate with the receiver in your engine. It is also a full-blown decoder programmer that doesn't require any other components to be able to program. It uses a rotary dial for controlling the speed, which some people might prefer over the S-CAB slider. I have not bought this throttle yet, but it is on my to-do list. I have, however, gotten positive confirmation from others that it works perfectly with S-CAB-equipped engines. (photo was copied from the CVP web site)

How is the Real-life Running Experience?

In my normal operating of my layout, I notice no difference, except that it takes less time to get the layout running, and that I have no more stalling or dirty-track issues.

What I see is that the radio-control/battery-power solution trades off more complicated layout wiring for more involved locomotive work. It also trades off having to deal with rail contact issues for dealing with battery charge-holding issues. For me, battery-powered engines wins hands-down! Battery-powered engines can be run on stand-alone dioramas, used to test track, and make painting and cleaning wheels much easier (no need for a complicated/expensive powered stand). In my experience on my home layout for the amount of time I run my engines, I only charge them whenever we have a local train show, about 4 to 6 times per year! Not at all an inconvenience considering I don't have to clean or wire my track anymore.

It is my experience that the batteries hold their charge for months. As I am writing this, it is August. The last train show we did was in April. I am still able to run my engine from when it was charged after that April train show!

I have only used two systems, namely the old DC-only transformer (running one engine in N-scale), and the Digitrax DCC Chief system. Both the clubs I've belonged to used the same Digitrax DCC system. Digitrax' system is powerful, but also very complicated. If it and the layout work well, you can get into a routine that will help you run your engines. However, when the system starts beeping at you, it gets very complex. There are lots of things that need to be debugged.

When I was using Digitrax on my small home layout, which typically only had two engines on it, I always had to re-select the engine that I wanted to run. In addition to the dirty-track/dirty-wheels issue, I also had communication problems. The Digitrax throttle (DT-400) had no way to turn it off to save the battery, so you always had to mess with taking the battery out after each operating session. Programming a sound decoder required many other parts and wires and a special programming track/section. So, it was doable, and it was very powerful, but it was so complex, involved, and time-consuming. All of that complexity is gone now that I've switched to dead-rail and battery-powered S-CAB! I am a computer programmer by profession, but at the end of the day (or to take a mid-day break), I just want to run the train, not also debug my layout!

At our club layout, we have some sort of problem at nearly every show. Trying to debug the system while entertaining the crowds is very stressful. The problems are so varied that it is hard to debug the system without the proper measuring tools. So, I usually wind up bringing a large collection of tools with me to each show just to handle any potential problem the system throws at us. My battery-powered S-CAB engine just keeps on running regardless of what's going on with the Digitrax system. As I am wracking my brain trying to figure out what is wrong with the layout this time, I keep thinking in the back of mind, "How much more fun would this be if every member of the club was using battery-powered S-CAB?" We could just hook up a 5-amp, 12-volt power supply to the main lines, remove all the wiring to the turnouts, and have a fun time running our trains and conversing with the audience. Life would be simple again! Isn't that what technology is supposed to do for us; make our lives easier, not more complex?

Inside the Throttle

At a train show in early 2015 I accidentally dropped my throttle on the concrete floor of the facilities. Ever since then something rattled inside. I finally took some time to open it up. While I had it open, I figured I'd take some quick shots of it for those who are curious about what's inside. On the left you can see the antenna. On the top are the CV slide switch, the on/off slide switch, and the USB battery-charging port (from left to right).
There is an NWSL rechargeable battery in the throttle, identical to the one I have installed in my S-scale NW2 switcher.
It is held in place with some Velcro®. This, actually, turned out to be my "problem". The battery had almost completely slipped off of the other Velcro piece, which was the source of the rattle. So, the throttle survived the fall intact; not even an exterior scratch!
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While I had it open, I snapped a photo of the Linx radio-frequency module that sends out the signal to the receiver in the locomotive. This is the same chip that the CVP T5000 throttle uses to send its signals out.
The long chip in this photo might need to be replaced if Neil comes out with a significant upgrade to the system.
At train shows (or even at home) I forget how to turn the engines' batteries on or off (since I use reed switches for both), so I made myself this cheat-sheet, which I printed and taped to the bottom of the throttle. It tells me where the reed switches are located on each engine for turning on or off the battery power.

Who Else is Using S-CAB?

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The basic S-CAB system (the decoder/radio receiver board) was designed to fit in HO-scale standard-gauge locomotives. The S-CAB Yahoo Group has a number of members who have indicated that they have successfully installed the S-CAB system in HO-, O-, and S-scale engines (including Sn3 equipment). One member reportedly installed the system in an N-scale engine by using a trailing box car to house the decoder). Several of the members are also using the battery-powered option with great success. As I mentioned above, also check out Neil's blog for a description and photos of his and other's installations (I have a blog post there as well about my S-scale NW2 conversion). I have included a few links to other users of the S-CAB system.

A Couple of Final Thoughts

I love using the S-CAB system. Since February 2013, which was my first public showing of one of my engines converted to battery-power, I have been demonstrating and answering questions about battery power and S-CAB to anyone who shows an interest. What I have found is that with people's familiarity with rechargeable batteries in cell phones, that once I explain the basic premise, everyone immediately grasps the beautiful concept of using onboard electricity storage inside of our locomotives. No real "sales pitch" is necessary; the concept sells itself. Two of my fellow club members have bought the S-CAB system, and one is seriously considering it. I answer many questions received via e-mail from other modelers considering purchasing a battery-powered system or S-CAB specifically. I am happy to help.

I usually bring my American Models FA-2 locomotive to train shows. It pulls a dummy B- and another dummy A-unit, as well as a train of about 15 cars. With the club's Digitrax system powering the rails, my FA-2 runs the entire show (these are typically 6 to 8 hours long). I bring it home and charge it overnight. The next day it will run the entire show again. It has a 2,000mAh battery in it. My NW2 has a 1,000mAh battery and it will run for at least 4 or 5 hours. It ran an entire day's worth at one show. It depends on how fast I run it, and the length of the train it has to pull. The RS1 I have has only an 850mAh battery in it. I can get about 3 hours on the club layout. However, that is a delicate engine, so I don't bring it to the shows too often.

I have had no problems with interference when operating my S-CAB engines on the club's layout in public shows. All shows we do have many other clubs operating their layouts. A lot of clubs in the Houston, Texas area use the Digitrax system, but the local G-scale club uses CVP and Crest. Our Digitrax system sometimes has to have its internal address changed so as to not conflict with the other clubs' Digitrax systems. However, my S-CAB has had no problems, even operating right next to the G-scale layout.

Powering our locomotives with batteries is a concept whose time has come. It is time to put an end to stammering and stalling engines on our model railroads. The old days of DC and DCC systems powered via the tiny electrical contact between the wheels and the rails, which have been around for more than 60 years, needs to come into the 21st Century. With our technology we can do so much better. Let's make this hobby fun again. DC allowed us to run our engines from a control panel or a walk-around throttle. With DCC we can run multiple engines independently on one layout. With battery power we can do so without any loss of power and with great simplicity of layout construction!