# Battery/RC in the Lionel BN GP20 w/sound



## Mike Toney (Feb 25, 2009)

A friend got me one of my favorite diesels, one of the power hungery 4 motor GP20's in BN cascade green. One of the few diesels that can run on my outdoor railway. I know there is little room in the powered unit for onboard battery power. And I would like to retain the railsounds as the sounds pretty darn good to my ears. I have the chance to pickup the matching unpowered diesel. I could put the batteries in the trailing dummy engine along with the RC. But what RC will not blow up the rail sounds boards? Need straight DC and no PWM. I have also considered making the powered unit single axle drive on each truck, eliminating one motor on each to reduce power draw. I do not pull long trains, so she would have plenty of grunt for my needs. Or has batteries come far enough to support the 4 motors and sound if I stuff a single big battery or a pair of smaller ones in the dummy unit? Thanks Mike


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## Greg Elmassian (Jan 3, 2008)

You can filter the PWM from the RC system to pretty clean DC:


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## Mike Toney (Feb 25, 2009)

Ok, who's circuit is that? Something from Crest?


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## Greg Elmassian (Jan 3, 2008)

Notice the Crest part number on top? (They all start with "CRE" as in "Crest", just like Aristo parts start with "ART")

RLD has them in stock, you can also buy them from the new Precision RC company who has taken over the Crest product line.

I will provide links to make your life easy:

http://rldhobbies.com/pwctolinearboard.aspx

(Precision RC only shows the new "active" board, and it's $70 so forget that one)

Regards, Greg

Greg


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## Mike Toney (Feb 25, 2009)

Thanks Greg, I figured the "cre" in the part number ment it was a Crest board. Mike


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## Greg Elmassian (Jan 3, 2008)

No problem... I think those boogers draw a lot of current, but they are pretty bulletproof... too bad Lionel did not continue in the LS market outside of toys.

If Lionel had kept going and MTH would have kept production going on the locos (instead of doing runs only once in a number of years), a guy could do some decent 1:32 modeling.

I almost went 1:32, but the lack of manufacturers, the flakey DCS in the MTH (not suited for outdoors or simple electrics) and how small it looked on the ground took me to 1:29.

Greg


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## Mike Toney (Feb 25, 2009)

I have seen someone fix the swinging pilot issue on them and really detail up the bodies. Not a bad looking engine for the era of large scale they came from. Typical Lionel styling for the era. It is a shame, one of thier Atlantics with a reworked chassis, metal wheel sets would probably sell well today, or a 2-8-0 chassis under the same boiler. The diesels just needed an updated power truck with a single motor driving both axles instead of 2 motors and toothed belts or 4 motors. I am wondering how much thier pulling power would be cut if I removed 1 motor in each truck, say dropping the inboard motor on both. I might pull 5-6 cars max most of the time. Plus the dummy engine I plan to get to hold the batteries and crest reciever and PWR board you posted. Feed the lead unit thru a 2 prone jumper(MU)cable to the track power feeds. Mike


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## Greg Elmassian (Jan 3, 2008)

Why do you want to take a motor out? Battery life? Should be little difference, power is used up by the effort needed, not the number of motors.

2 motors will draw about the same current as 1 given the same loads. Been proven over and over. The issue you may have is that the motors are not very efficient in the first place, but no reason to take one out.

Greg


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## Mike Toney (Feb 25, 2009)

This is true, and yes I was thinking of battery life. I should be able to fit a decent size battery in the non powered/non sound trailing locomotive. Will talk to Robbie at RLD about what batteries to fit. I want max run time, so I will go as big as I can fit. Mike


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## Greg Elmassian (Jan 3, 2008)

that sounds like a good plan, stuff the other loco with batteries


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## Mike Toney (Feb 25, 2009)

That was my thought, since a dummy unit was offered, better looking that a dedicated battery car, which I cannot stand having the same car with the engines all the time. I will never have a layout that will challenge the pulling ablity of the single powered diesel. I might visit one but I will keep the train length reasonable. I emailed RLD for a cost on everything I need to do the install. Thanks Greg. Mike


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## Mike Toney (Feb 25, 2009)

I will post this here as well. Ran the GP20 on track power tonight, draws around 2.5 to 3 amps estimated. Running with a pair of 1 amp transformers paired up to give me 2 amps of power to the track. I can run for about 5 min or so, then I start loosing the LGB 1 amp transformer with its electronic circuit breaker. Buddy is going to bring his 10 amp MRC g scale throttle over as the battery stuff is waiting on him to make his next payment to me for the train he is buying from me. Robbie over at RLD is recommending the 6000mah, 18.5 vt battery, along with the Revo TE and the needed PWM to Linear board. Whats my run time going to be on a fresh charge? Wish I had a way to measure the amp draw on this beast once I have the 10amp throttle hooked up. Need to invest in a better multi meter with the induction pickup for amp reading. The Revo will have diesel sounds. Not sure its any better other than I could control the horn. Not sure that can be done once on battery with the factory Railsound boards. Lionel used a track side button you would push to trigger the horn or the bell depending how it was wired. Being the engine is DC, not sure what that button did. The old AC powered 3 rail stuff would superimpose a DC current over the AC track power to trigger a DC biased relay for the whistle or horn. The old Railsound board sounds good other than lacking the turbo whine a GP20 would have. More of a GP9 normaly aspirated diesel sound. Not sure what the new Revo diesel sound is like. Mike


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## Greg Elmassian (Jan 3, 2008)

I answered your post on LSC, but will add that you can buy a meter that will read up to 10 amps at Harbor Freight for $5 and even less or free on sale.

Greg


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## Mike Toney (Feb 25, 2009)

I will check that out tomorrow, thats one tool I am lacking still is a meter that can read higher amps. What do you think run time will be, say based on a 3amp draw running light engine? Just looking for a ball park. I know Robbie was running a pair of Aristo GP40's off a single battery car for several hours at the open house a couple years ago, and he was pulling a decent length train. Mike


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## Greg Elmassian (Jan 3, 2008)

well, the easy calculation is divide the battery capacity in amp hours by the amps, and you get hours.

so a 6000 mah, is a 6 amp hour battery converting milliamperes to amperes.

so divide 6 amp hours by 3 amps and you get 2 hours.

That is the quick way to do it.

Greg


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## eheading (Jan 5, 2008)

Greg, is the Lionel, GP-20 1:32 scale, or 1:29??

Ed


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## Mike Toney (Feb 25, 2009)

The GP20s and GP9 from Lionel are roughly 1:32nd in the body and 1:29th in the trucks. The look good pulling the rolling stock of thier era such as Lionel's own as well as LGB, Delton, Kalamazoo ect. Should also look good pulling the newer MTH line of gauge one rolling stock. What a few here and over at LSC are forgetting is I am not tied to sound, in fact, most times I have the switch for the sound set to off. Both of my lines are small and the constant drone of the sound quickly pushes me into a sensory overload and risk of a meltdown. On larger lines like the RLD shop layout, the sound fades away due to the size of the layout and being outdoors. I could care less if I can blow the horn, I have yet to find a board that duplicates the sound of the Prime 990 3 chime horn these units had back then. I do want to eventualy turn them from GP20's into the GP10 units the local shortline had. The stock sound already has the correct non turbo sound. I just need the body hatch panels from the Lionel GP9 body to replace the large dia GP20 fans. The dynamic hatch is removable already. I did some test running tonight with a MRC power command 9500 throttle with meters. The unit shows its age as it takes full 12 vt to run a reasonable speed in short hood lead direction. 2 to 2.5 amps with the high amount in the tight R1 curves. Running long hood lead, the voltage can be dropped to 7-9 volts, and amps fall to 1.7 to 1.9ish. I am going to flip the trucks around, to regain better short hood lead operation. I have a NOS set of trucks to swap in when these give up. Once on battery with the track pickups bypassed, she should run much better yet. Thier wiper pickup is a bit light weight to feed 4 can motors and a sound system with full lighting set up. There is like 5 bulbs lighted plus the beacon circuit in forward direction and 4 plus the beacon in reverse. I plan to get one of the high hood Lionel GP9's to repaint into BN eventually. I will set it up to feed off the same GP20 battery tender. Since I have a couple months before my friend can make his next payment, I have plenty of time to consider options for the RC part. I have nothing, so Revo isnt required, I could go RCS or Airwire ect. Just have to have Linear power to keep the lighting and sound boards happy. Revo can do this with an extra filter board. Mike


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## TonyWalsham (Jan 2, 2008)

Mike.
I should point out that RCS ESC's are not Linear. Like Airwire and just about every other on board ESC they are pwm. As such, like the Revo they too would require fitting the Crest 57091 if you wanted Linear output. However, be advised that in my experience, the filter pcb reduces the starting smoothness of the power control. It becomes noticeably a bit more OFF & ON than I would find desirable.


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## Mike Toney (Feb 25, 2009)

We will see how the Lionel unit does, they have a pretty steep gear reduction that might help that a bit. I knew most every controler does PWM to help get engines started smoother at the sacrifice of motor noise and heat. I had PWM control in an aristo FA1 and running at a slow shortline speed, ie like 10-15 scale miles per hour, within an hour both motors were so hot one could fry an egg on them. That engine didnt need PWM to run slowly or start smoothly, but it was built into the RC control that engine had. At higher track speeds the motors ran cooler but that was faster than I wanted to run. If it wasnt for the fact I wanted to start and stop this engine remotely, I would just step up my normal on/off switch and charging port, then adjust the speed with an onboard critter controler board. Gonna go drop the motor blocks and reverse thier positions to "milk" the remaining life from the motors. Being that I dont have a Revo set up, is it any less expensive to get the RCS set up, along with the needed PWM to Linear board? Any benefits to going with RCS over Revo or is it just a wash feature and price wise?


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## Mike Toney (Feb 25, 2009)

update, reversing the trucks has no effect on running qualites, still runs better in reverse over fowards. Looks like the voltage loss is in the factory electronics. Looks like I maybe just removing the old stuff other than the beacon light circuit and putting the battery and Revo or whatever in the powered unit. Mike


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## Greg Elmassian (Jan 3, 2008)

Mike a few comments:

In post #17 you talk about swapping trucks to regain better short hood operation, so I guess that is where you decided to swap them, but nothing changed according to post #20.

So, it would infer that nothing wrong with trucks. Could it be as simple as inadequate power combined with more lamps running forwards than reverse? (less currend drawn in reverse due to fewer lights, thus better running?)

My opinion is that the pack you are using is wrong for G if it tops out at 12v, and the MRC 9500 is rated 30VA, so 2 amps draw at full throttle would be maxing it out pretty much. Also, never trust meters in an inexpensive system until you check them with another meter. 

Another item: the pulse power "goes away" around 5 to 6 volts on the output, so if you have heating of the motors, you most likely have a different issue.

Greg


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## Mike Toney (Feb 25, 2009)

You misunderstood Greg. The motor over heat issue was on another engine that didnt like PWM power. That was years ago. My point about the running better one way than the other is that the problem lies in the onboard Railsounds electronics. There is only 1 bulb differance between foward and reverse direction. The speed vs voltage needed is way more than just what a bulb would consume. Yes the transformer is underpowered, but it gives a baseline and it will run the engine in either direction for as long as I want and not overheat the transformer. Its only a temporary set up. I think the next step is to eliminate the factory sound, and just tie the lighting circuit to track power(its not constant lighting) and the motors right to the track pickups and see how she runs. Atleast by not needing the PWM to Linear board, I save almost $100 off the cost of the RC stuff. Wish someone else made ready to use Prime Stratolite beacon circuit(not a kit) other than Richmond controls. His stuff is great but a huge waiting list. Mike


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## Mike Toney (Feb 25, 2009)

Ok, I gutted the electronics, found some burnt parts on the lighting board, so I lost the beacon on the lead unit so I removed the stand alone beacon board from the dummy engine for now to restore the roof beacon on the lead unit. In the pic below, we can see the culpret for the high amp draw in foward direction. Mike


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## Greg Elmassian (Jan 3, 2008)

Wow, well that sure could be the issue... congrats on digging in and finding it.

Greg


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