A battery power question (from a track power guy)

[TonyWalsham]

Ron,
That depends on the charger.
I used to make one that charged NiCd batteries from track voltage.
Unlike the requirements for charging Lead Acid Gel Cells, the track voltage when charging NiCd's had to be significantly higher voltage than the battery voltage for it to charge those batteries.
As the track voltage had to be at least 5 volts higher than the battery voltage it meant the loco ran noticeably faster on track power than when on battery power. The speed changes were very noticeable at each piece of dirty or non conducting track.
Sure it is possible to do it but short of having some low track voltage to high voltage logic built into the charger for the overhead, the high track voltage situation cannot be avoided.
To me the real killer of the idea is the extra complication necessary to install it over just straight battery power where the track pick ups are simply disconnected.
Plus you will have to keep the track quite clean and conducting all over the layout for it to work effectively.
Where track and battery power can be combined effectively is with a constant voltage on the track and batteries as back up only.
That permits very complicated track work without especially complicated wiring. Simply have dead sections of track longer than the loco pick ups where reverse loops or "Y's" are located.
Trust me I have been doing this stuff for 20 years now.[}:)]

[emipapa]

Hi all,
I have but one question? What voltage will the charger that gets its power from the rails operate on, most chargers use 110/120 volts.
Just my [2c],
Ron

[Anonymous]

QUOTE: Originally posted by kstrong

Just to clarify, you're not using track voltage to control the speed of the train, correct? For that, you've got an on-board throttle. Because if you're varying the voltage going to the track and only charging the batteries when that voltage gets above a certain threhshold, you're going to be charging your batteries only when the trains are traveling at mach 2.

Later,

K

That's basically correct, but only when the OTHER guy's trains are going mach 2.

To be sure, the only time your locomotive could pull any track power would be when his power pack is at 100%, or even higher. On your own track you'd be running the rails at a higher voltage than anyone would want to see on their DC locomotives.

Mark in Utah

[kstrong]

Just to clarify, you're not using track voltage to control the speed of the train, correct? For that, you've got an on-board throttle. Because if you're varying the voltage going to the track and only charging the batteries when that voltage gets above a certain threhshold, you're going to be charging your batteries only when the trains are traveling at mach 2.

Later,

K

[Anonymous]

QUOTE: Originally posted by cacole

Trying to have an internal charger means that you must retain electrical pickups to your wheels. This will short out your battery if your layout is not properly insulated, and your trains will come to a screeching halt. Cut all electrical contacts to your wheels and it doesn't matter how many reverse loops you have.

Depending on the type of batteries you intend to use, they could explode if shorted out for too long a period of time.

This is mistaken, as any charger circuit inside the locomotive will isolate the on-board battery from the rails. If the track is dead, or shorted no current can possibly go from the battery back into the rails.

An on-board charger system would only charge the batteries when and only when the track voltage is high enough. During all other times there would be no effect to the track system, and no current being drawn from the track for the locomotive.

Mark in Utah

[cacole]

I still think it's not practical. I don't use track power for several reasons --

First, the ground is so hard here in Arizona that it would have required a ditch-witch to dig the trenches for electrical wire.

Second, I run live steam, which spews oil onto the track, and I didn't want to have any problems with dirty track.

Third, my back yard layout has numerous reverse loops and crossovers.. Having wired a 20 x 40 foot HO scale club layout, I knew the many things that can go wrong with wiring a complex layout.

Consider the following experence I recently had with a Bachmann Shay:

The new Bachmann Spectrum 1:20.3 scale Shay comes with a complete wiring schematic and instructions for installing DCC. Using their instructions, I installed an AirWire900 Wireless DCC receiver/decoder and SoundTraxx DSX Sound-Only decoder into one. On the test bench, everything worked perfectly -- but when I took the locomotive outside, nothing worked.

After a lot of wire tracing and hair pulling, it finally dawned on me that Bachmann's schematic diagram is wrong, and the internal circuit board was still connected electrically to the wheels, causing a dead short when placed outside. I traced down the wires that were connected to the trucks, which turned out to be a different color code than Bachmann's diagram showed, cut them, and everything works fine.

Trying to have an internal charger means that you must retain electrical pickups to your wheels. This will short out your battery if your layout is not properly insulated, and your trains will come to a screeching halt. Cut all electrical contacts to your wheels and it doesn't matter how many reverse loops you have.

Depending on the type of batteries you intend to use, they could explode if shorted out for too long a period of time.

[Anonymous]

I think a few people are a little confused how such a system as I've proposed would work.

1. No current would be drawn by a float-charged locomotive unless the track voltge is above a certain level AND at the right polarity. For a 12 VDC internal battery (13.5 VDC float), you'd have to run the track voltage at least above 16 volts. If you're at a friends layout and he's track powered your train would have no effect, as his track voltage most likely would never go high enough to trigger the on-board battery charger.

2. The on-board battery charger should be current limited, and float the batteries at the proper voltage for indefinate connection. Again, even if the friends track voltage could go high enough, he'd still be safe from current overload.

As for worrying about the track electrical conncetions, you'd only really worry about that on the storage track. The rest of the track would get a cursory clean up, and where it works, it works. Where it doesn't work, you'd never know. The idea isn't to maintain 100% electrical reliability around the track, but to only maintain SOME electrical connection, like 50%?

Mark in Utah

[John Busby]

Hi Mark
I have both the solution is as simple as insulated wheels on the locomotive
and of course if it is a conversion you have that allready but must remove the pick ups.
if you where using the track to charge the battery you would have to have the pick up
which seems silly for a locomotive that dosn't need them.
And would cause problems for the track powered trains and you would to have to clean track for a locomotive that again doesn't need it
regards Jjohn

[kstrong]

No power to the rails here. The primary reason for going to battery power is to avoid having to clean the rails, run wiring, worry about reverse loops, and stuff like that. If you keep your railroad wired for electricity, then you still have the headache and the problems inherent with electrical conductivity, along with the added expense of converting your locos to batteries.

Theoretically, you can charge the batteries via the rails while you're operating, but then it quickly becomes one of those "why would you want to?" issues. You would still have to maintain proper electrical conductivity and all that stuff. You may as well just run track power at that point and save yourself the hassle of installing the batteries. You also still run into the same pitfalls with reverse loops, where you risk switching the polarity of the power going to the batteries. Not a good thing.

A compromise would be a powered passing siding where the train would stop for a few minutes and get a quick recharge. It would have to be stopped on the siding for a fair lenght of time to get a decent charge, but it is theoretically possible.

I personally think it's far easier to either include an auxillary plug in the back for extra batteries for long runs, or make the batteries removable so they can be swapped out. Both of those solutions are far easier than trying to rig up some kind of charging mechanism for the rails and keeping them clean.

Later,

K

[cacole]

I haven't seen the name Alan Olson on these forums. I have a video tape he produced entitled, "Modifying the Bachmann 2-8-0," in which he shows sound, battery power, and other modifications to the Bachmann 1:20.3 Consolidation.

He uses the RCS system, and claims that he also has the Phoenix sound system -- but the whistle in his locomotive sounds so horribly electronic and tinny that it can't possibly be a Phoenix.

My SoundTraxx Sierra and SoundTraxx DSX Sound-Only decoders have very realistic bell, whistle, and other sounds, and I have been very pleased with all of them.

One other big advantage to battery power that I neglected to mention in my earlier post is that no amount of dirt, grease, grime, or rust on the track has any effect at all on locomotive performance, and you don't have to worry about loose electrical connections at rail joints or anywhere else.

A disadvantage to battery power is that if you have a derailment, the locomotive will continue to run happily along because it has not lost its power.

I saw one account where a G-scale train was ran along the expansion crack in a concrete floor to guide it, and didn't even use track.

[cacole]

When I convert a locomotive to battery power, all of the electrical pickups are removed from the wheels so there is no way the track power can cause problems, and the battery cannot effect the track power people.

If you don't do this, your battery powered loco could possibly cause an electrical short. I run only battery power on my home layout. If I wanted to take one of my locomotives and run it on someone else's track-powered layout, this could easily be done without causing any conflict at all.

I use 12 Volt Gel-Cell batteries that are recharged with a common automotive charger. I have read of other people who have a special section of track that is connected to a charger so their batteries will recharge while their locomotive is parked, but they are not using a built-in charger.

Keep the charger external so it doesn't interfere with the people who are running from track power. If you tried to make the charger internal, it would draw too much power from the track and could possibly overload the controller that is being used to run track-powered locomotives, causing them to run slow or even burning out the power pack.

[Anonymous]

In an earlier thread I proposed this very ting, running under battery but installing a charging circuit to charge the batteries from the rails. You'd have to run the rail voltage hot, but then you'd never have your batteries go dead when operating.

Several people poo-poo'd this idea, but I've been float-charging batteries my entire career when operating equipment (21 years). You'd defintaely have a non-standard rig, but is that a problem?

Mark in Utah

[markperr]

For those of you who run exclusively battery power, do you still have track power to the rails available.

Tha reason I ask this is that everybody in my local GR club runs track power but I'm leaning toward battery operations in my new layout.

If you DO do this, are there certain precautions that must be taken in order to prevent shorts or other potential electrical problems?

Can you recharge the batteries from the rails?

Mark