# GP9 battery



## dpotp (May 25, 2011)

I need advice. I will be receiving a GP9 soon and I will convert to RC and battery. If anyone has done this do you have any helpful suggestions? I will be using Li-ion 14.8V batteries and I would like to install the Airwire system. What is the larges capacity battery I can install?


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## Dick413 (Jan 7, 2008)

I know a 5400 will fit. 
Dick


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## toddalin (Jan 4, 2008)

I don't think that you will be happy with the top speed. You need another "cell" or 2.


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## dpotp (May 25, 2011)

I thought Airwire recommended 14.8 v batteries for there system.


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## bnsfconductor (Jan 3, 2008)

Plenty of room in a GP9 for all the stuff. I use a 14.8 NiCad, and get 2-3 hour run time on a charge. With a trailing B unit (or boxcar) that has extra batteries I can run 6 hours without any problems. I mount the batteries underneath the long hood, right below the fans. For me this serves two purposes. One it keeps the frame floor clear for all the electronic boards, and secondly it helps make a seal from the fans that prevent rain/snow from getting inside the locomotive. 


Craig


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## Dick413 (Jan 7, 2008)

dpot 
yes they do recommended 14.8. I can get close to 4 hrs. on a 5200 and if you use a dropin real easy install. set at 28 step anything over 14 starts to look like the old lionel 
and that's pulling 10 cars.


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## dpotp (May 25, 2011)

Thanks for the help guys


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## toddalin (Jan 4, 2008)

If you follow the link, you can see the Geeps running at about 16-17 volts volts to the rails pulling just 5 railcars or so. Maybe a bit fast, but certainly not like a Lionel. (Video makes it look a bit faster than they are.) Remember that with RC there wlil be some voltage loss through the system so you won't get all 14.8 volts.

I can run with up to ~22 volts to the rails and even then these don't derail on 8-foot diameter curves. 

T&LBRR Running Itself


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## Dick413 (Jan 7, 2008)

Toddalin 
A full chg. 14.8 is close to 17volts


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## rmcintir (Apr 24, 2009)

I run 5 18650 li-ion cells per loco. They work quite well for my purposes. I buy from dealextreme.com and use their 2 and 3 cell holders. No corrosion problems in FL salt exposure. I don't pull huge car loads, typically 6 cars and they run for 3 plus hours. I had NiMH and they failed in 2 years. So far Li-ion in general lasting longer. Easy to replace (fewer and in battery holders instead of solder tabs).


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## TonyWalsham (Jan 2, 2008)

Posted By Dick413 on 20 Aug 2013 07:24 PM 
Toddalin 
A full chg. 14.8 is close to 17volts 
That 17 volts is only when freshly charged, Soon after switch on the voltage will drop to the nominal a14.8 volts and stay there until almost discharged. Then they drop off the cliff soon afterwards.

Ni-Cd's usually cost more than NiMh batteries but the pay off is they last longer (1,000 recharges compared to 500 for NiMh) and do not self discharge as quickly as NiMh.


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## Greg Elmassian (Jan 3, 2008)

What Tony said.... to amplify, measuring the voltage on a battery with no load is usually of little value. 

(Yes, I know how a sophisticated battery charger works and will measure no load voltage during it's testing) 

Greg


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## dpotp (May 25, 2011)

I will be running 10 cars on this train, all have metal wheels. I had planned on getting the batteries from Tenergy. They do not carry a 5400 but they do have 3 14.8 V batteries at 5200 mAh. I do not have the engine so I can't measure the inside. Does anyone have those measurements Thanks again for all the help.


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## Dick413 (Jan 7, 2008)

dpotp 
here is the one I use http://www.all-battery.com/AT_Tener...00mAhRectangularBatteryPackWithPCB-31892.aspx 
use school as a coupon and get 12% off 
this will fit


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## dpotp (May 25, 2011)

That's just what I need , thanks.


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## Daniel Peck (Mar 31, 2009)

use the 5200 pack... I got those in mine and you have 3-4 hours of run time if not more only pulling 10 cars.


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## dpotp (May 25, 2011)

5200 pack sounds good. I guess I should replace the light bulbs while I have the locos are apart with LEDs. I saw somewhere what type of LED gives the best results but I cannot locate it. Plus is there one place where I can get the LEDs and drivers?


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## Dick413 (Jan 7, 2008)

dpotp 
? you said you where going to use airewire if you are going to use a drop in you do not need to change any wiring the markers are led's and with airwire you can turn lights on or off at any time also 
the dropin has charge jack, on-off switch and switch for sound. 
Dick


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## dpotp (May 25, 2011)

This GP9 is old. I have had to order a lot of parts to rebuild it. I was also thinking of the other locos I have that will be connverted in the future.


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## Greg Elmassian (Jan 3, 2008)

I think TrainTek sells replacement boards with the LEDs on them. 

Greg


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## Curmudgeon (Jan 11, 2008)

I've been doing Geeps since they first came out...what was it, 96? 98? 
Started with NiCads, went to NiMH....14.4V is ideal, actually, if you time a section and calculate prototypical speed. 
I don't use 787's. Or ELT's. 
Just a phobia. 

On F units for passenger service, they get 16.8's. 

Generally, I have tried to avoid slot trains. 
Been somewhat successful, too. 

TOC


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## Greg Elmassian (Jan 3, 2008)

Yep, they are geared way too high! 

Kind of the opposite of the Aristo E8 where you can barely get prototype speeds with 22 volts! 

Greg


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## dpotp (May 25, 2011)

As in the past you have come thru again Greg with your help. I just finished installingl Airwire in an older Aristo FA-1. It was a rather easy install. I have the headlight comes on when power is supplied and the number boards I have on Elite 1. I put the cab light on Elite 2 but the light does not stay on. Anybody have any suggestions.


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## Fred Mills (Nov 24, 2008)

Suggestion: 
The cab light should NOT be on when running. This would ruin the crew's night vision, so would not be left on. The same with the classification lights. They would only be on if (1) White lights would indicate a train is an extra train, not on the employees' timetable (2) Green lights, if there is a second section of the train is following. Red would never be shown in a class light, unless the locomotive was running in reverse on the end of a train. 

On the rear of a locomotive, the lights are usually off, unless running in reverse, when a head/or back-up light would be on.


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## Greg Elmassian (Jan 3, 2008)

I replace the red/green classification lights with white/red .... now there ARE indeed railroads who do have some kind of red light were USAT put it... NYC I believe. 

But traditionally the classification lights are in one place, and a red light on the back of a loco running light was in the center of the loco, sometimes a second light in a headlight, sometimes somewhere else. 

Since I model Santa Fe, the class lights we as Friar Fred has described, except for the running light situation as described above. 

(that red/green class light has always bugged me on USAT locos) 

Greg


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## dpotp (May 25, 2011)

That is why I have the cab lights on a function key on there own so I can turn them on when I choose. And I know about running at night, I have an engineer license and have run a F7 on a line in Wisconsin.


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## Greg Elmassian (Jan 3, 2008)

Wow, if you can add to the knowledge base here that would be great, any other F7 tidbits? Not that I am a rivet counter, but it's fun for me to try to get close to how the prototype ran. 

Yeah I have the cab lights on a separate function too, but thinking might put them on some automatic thing. Not trying to sway any purchasing decision, but the Titan has about 12 lighting outputs, want to do the 4 LED rotating beacon for someone soon, built up of 4 small surface mount LEDs. 

Greg


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