RailPro on Battery Power

[Terry]

Rings all-in-one design makes it quite easy to come up with a fully battery powered locomotive.  This example uses an 850mah Lipo cell which produces 3.7 volts.  The little(!) circuit board under the tangle of wires boosts the voltage to 12 volts.  The unit is charged externally by a hobby LiPo charger.

This installation lasts about one hour of continuous running on a level circle of tracks.  The pay off, however, is in operation.  We get from two and a half hours up to an incredible four hours on the layouts we visit.  Why the difference?  Just like the prototype, it’s ‘hurry up and wait’ progress, although the ‘hurry up’ might be a misnomer.  Our five units (from Bachmann, Athearn, and Walthers) play nice with the DCC and DC folks, and unless we tell people, no one knows the difference.

NOTE!!!  LiPo cells can explode when heated, shorted, punctured or used with a non LiPo compliant charger!   Unless you can fit the connectors the cell comes with into your conversion, you will need to make some changes.  This is the only twitchy part of these projects.

Parts sources:
   LiPo batteries: from the internet, I searched by ‘850mah single cell LiPo’
   voltage converter: Pololu U3V12D12 from Litchfield Station hobbies
   Plugs/wire: Miniatronics 50-001-02

A note about that tangle of wires.  Originally we thought best to make the battery removable for charging.  This extra wire allowed us to lift the RailPro and slide out the battery.  In the end, we taped the battery to the floor.  This was easier to handle.



[William Brillinger]

Very Nice Terry!  Do you have any diesel examples?

[Note: I inserted your image into the post for easier viewing.]

[G8B4Life]

Welcome Terry.

Your post will certainly give a few here a renewed vigor in their quest for deadrail. I'm still yet to see anyone fit all this into a hood unit though. Have any of your group done that yet? It would be interesting to see them.

- Tim

[Terry]

Hi Bill,

Funny thing; tonight I received the batteries to do a GP35 conversion.  I've had the chance to confirm the fit (rear end of long hood), the placement of the Ring module and the sugar cube speaker toward the cab.  There's many a slip twixt the cup and the lip. . . we'll see how the rest goes.

More later I'm sure -
Terry

[KPack]

Terry - This is the first picture I can remember of someone actually using Railpro with a battery.  I'm sure people have done it before but I don't remember seeing it.  Good info on the converter from Litchfield Hobbies.  That is certainly a tiny circuit board, which is great considering all the other stuff that takes up room on an install like this. 

This particular install doesn't allow charging from the rails, does it?  So in order to charge you must disassemble the tender and manually plug in the battery.  I'm not opposed to do that, I would just need to find a way to easily access the plug; hopefully without having to remove the shell in order to do so.

I model only diesel (late era) and removing the shell on my models is a delicate procedure.  If I could find a way to make the plug easily accessible then I would be much more comfortable.  I know that people have talked about putting the battery in the fuel tank, but I have yet to see a model that will actually allow that, as the fuel tank is normally taken up with the mounting for the motor.  I'm looking around at other batteries and wonder if they will work.  Lower mah batteries are smaller, but how long would they last?  I'd love to get a good hour out of a locomotive with lights (LED) and sound. 

-Kevin

[Dean]

Why can't the battery charger be connected to the tender wheels. Then you cold pull the locomotive on a dedicated track and charge the batteries.

[nodcc4me]

I have read about that before, although it was done with DCC and box cars containing batteries. You would have to connect the cars to the locomotives electrically to run, then have a charging track siding. This would obviate the need to mount batteries in the engines. Unfortunately, you might still have to connect and disconnect the car from the locomotive at times. Of course, with steam engines the tender would make a perfect battery compartment, if there is enough room once the module and speaker are in place.

[Terry]

Hi KPack, Tuscarora and nodcc4me,

The charging is actually extremely easy.  The tender body just sits on the frame.  The body and frame fit very well and are designed to keep themselves aligned.  Most models I have seen are the same.  I just lift off the body and plug the lead from the charger, which is about 18 inch lead of the same Miniatronics twin wire/connector.  Although I could keep the unit on the rails, I choose to have a central charging station.

BTW, the fact that charging is external makes these compact installs possible.  Any other charging system, rails, etc., requires additional stuff in the loco.  In any case, I always prefer external charging - it's the KISS principle.

On another note, the GP35 progresses, the battery, now assembled, is two 500mah LiPos that sit just under the shell at the rear where they are attached to the body rather than the frame.  This floats them over the gear tower of the rear truck.  More on all this later.

Terry

[Terry]

Here goes, (if I can get this emall stuff to work), The first picture shows the subassemblies laid out.  The battery (two 500mah cells) were not included here as they were in process.  The main electrical structure holds the RailPro, the sugar cube speaker (below it), and the small narrow rectangle on the underside is double sided foam tape to connect the assembly to the top of the motor.
 


The ‘picture frame’ below this supports the structure from falling onto the front drive train, it is glued to the loco’s frame but not the electrical unit.  This makes for easier dis/assembly.  Also, you can now see the batteries stuck to the body. 



At this point the body literally drops onto the frame and the couplers hold the loco together.  It’s clear that this conversion has no lights.  It is a Mule, I try all kinds of stuff on this chassis, it deserves a purple heart.

Finally, the third picture shows the attachment to the charger.  The fourth picture shows the battery plugged in and the loco is running.  Doing this removes the need for a DPDT switch and some sort of socket for the charger.  In tight circumstances like this one it would be unduly complicated and bulky to go that route.





Going back to the first picture, the dynamic brake casting serves as the hatch.  The idea for this conversion happened when I was looking at the underside of the body and noticed it was a separate piece.   When was able to break it out, I figured the conversion was a  real possibility.  Once the hatch is back in place it looks like just any other Athearn GP35.

Cheers, I have run this loco on the workbench circle for well over an hour and the battery has plenty left.  Tomorrow the loco, Jerry and I head for a friend’s layout.  It is an industrial scene with a ton of switching.  We’ll see how this one works.

Thanks,
Terry

[Josephbw]

That really looks nice, good job Terry. 

Joe

[nodcc4me]

Nice work Terry! Looks very promising.

[Jwin]

Terry,
This is great, I will have to give it a try. Needs all the lights but this is a great start to becoming dead rail. Thanks for sharing

John

[Terry]

Sunday afternoon - just got back from Jay's industrial layout.  Loco worked beautifully over the maze of switches and crossings - flawless.  The sound really drew us in; and when idling, I kept wondering if I'd run out of diesel fuel - I guess being on battery added to that too. The session lasted two and a half hours and the batteries are still raring to go.  It was fun.

Terry

[Alan]

Terry,

I am curious why the allure of battery. Earlier today I was amusing myself after a module installation (and after break-in) by seeing how slow I could make my latest motive power addition craw with a 16 car train behind it. It traveled the whole railroad (about 150') at what had to be less than 1 scale MPH without a hiccup. Just for kicks I backed the train for the return trip at the same crawl. The trip included across many turnouts some curved and even a 3-way. It took a very long time.    While I was watching the train barely moving your battery thread came to mind. I even wrote myself a reminder note to ask you the question.

If an amateur like me can make conventional track electrical supply work this well what is about battery power that is so desirable?

[KPack]

Alan, the answer to that question, for me at least, would be to have reliable running on other layouts.  I could probably build my own with trackwork that would pass under most circumstances, but to be able to take a locomotive and place it on anyone's track without thinking twice about their track quality would make it worth it. 

Kevin