# Battery Pack



## Michael W (Oct 10, 2012)

Gday, I am looking for some advice regarding battery packs, my Aim is to have 18 v availabe with as much amps as I can squash in.
I am planning to run the locomotives with identical power packs to keep things simple.
The reason for battery power is that I want to wifi control my locos using gertbots.
Using batteries to power the whole thing just means I can just take my train to any layout and just run it...
Anyhow i dont want to have to take the battery packs out to recharge so I am thinking of utilising the already exsisting pickups and the track, when the track is stationary it goes into charge mode through the track, maybe even trickle charge through the track not sure how feasible this is. Has anybody expirimented with this sort of thing and which battries do you suggest?
Kind regards
Michael


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## Pete Thornton (Jan 2, 2008)

> Anyhow i dont want to have to take the battery packs out to recharge so I am thinking of utilising the already exsisting pickups and the track, when the track is stationary it goes into charge mode through the track, maybe even trickle charge through the track


I set up my first battery/rc loco to charge through the track and never used it. A standard plug/socket (e.g. RS 5.5mm or 5mm power plugs) worked just as well and meant I wasn't leaving the track energized.
A local garden railroader has power on his track for switch motors, coach lighting and to charge the locos while running.


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## chuck n (Jan 2, 2008)

I've never had much success charging from the track.

Chuck


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## Michael W (Oct 10, 2012)

Thanx pete, I want the track to be energized, as I want to use it as supply for all the lights, houses switches cameras etc.... How did you set it up and what batteries did you use? I am a bit reluctant to go li ion due to their volitility.
Kind regards


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## eheading (Jan 5, 2008)

Regarding the actual batter packs. I have pretty much standardized on the Cordless Renovations 18.4V 6000 mah for powering my engines. I actually use two of these in parallel which allows me to run my engines for many, many hours. They have worked well for me. They have been reliable and dependable, and are reasonably priced for ready made battery packs.

Ed Headington


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## East Broad Top (Dec 29, 2007)

The notion of charging batteries via track power has been around pretty much as long as folks have been running battery power. I don't know that it's ever been found to be all that practical or reliable.

First, there's the notion that if you're looking to charge your batteries all the time while running your trains, you need clean track. If you need to clean your track, why use batteries? Kinda defeats the purpose. 

Related to that, if your track isn't 100% clean, or you only have power to certain parts of the track, you'll be charging your battery only intermittently. That's not terribly efficient, and may be bad for the battery.

When it comes to the newer Li-Ion and Li-Po technology, they're particularly finicky about charging, balancing, and all that stuff. I'd definitely feel much more confident knowing those batteries are being charged by a charger that's designed specifically to charge them and will not over-charge them. You don't get that when you simply use track voltage to charge the batteries. 

The lion's share of battery folks find it easiest simply to install a charging jack somewhere inconspicuous on the locomotive and charge the batteries between runs. It's just much less headache, and a lot safer with the newer technology. That new technology is giving us 6- to 10-hour run times on a 5Ah pack, so the need to continually "top off" the batteries simply isn't there as it used to be in the old days. 

If you want to give it a go, more power to you (pun intended). I think you'll find the headaches far outweigh the inconvenience of finding an inconspicuous place for a charging jack. 

Later,

K


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## Totalwrecker (Feb 26, 2009)

I tried using just the tracks to charge and found out I didn't run often enough NOR with enough juice. That was with NiMh battery packs which were safe to charge in situ. The newer Li-ions I'm making to be removable to charge in a safe place, like inside my kiln! 3 packs for 2 locos should keep me happy.

John


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## Michael W (Oct 10, 2012)

Thanks guys, i think i did not express this very well, the track will carry current simply to power switch motors and light for buildings, cameras signals and so on, it is easier than running massive amounts of cables...
The charging would be an added benefit but it would be buffered by supercaps to avoid uneven voltage supply, however the main idea is to park the loco on a siding track and switch into charging mode. The track system will still be able to be run on straight dc so I can have running days and folks can bring their stuff along. If I take my trains somewhere I would like to just put them on the track, take my I pad and run them independet on track condition.
Hence my question for battery solutions. The rasperry pie intended to control the locomotive needs battery power regardless, hence it makes sense to go full battery power, however I want to get a battery solution I can put in any locomotive so I can use one charger and one system.


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## Totalwrecker (Feb 26, 2009)

I felt ok with leaving the NiMh inside 24/7, I won't trust the new li-ions, they are removable.
First you must decide the chemistry. 

Some gamble with the Li-ions and leave 'em on board. I can't afford damaging a loco so I don't chance it.

Wheels on track are not the best connection, for the least friction, minimal contact is best. I hide my controls behind hatches, a jack isn't that hard to hide. Park your loco over the plug and ratchet it up into your loco, you were going to park it there anyway.....

John


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## Greg Elmassian (Jan 3, 2008)

You don't need clean track, or even continuous track power to do what you want, in fact quite the opposite, by having battery power, and "topping up" whenever it is opportune, you are quite the opposite.

Also the battery chemistry has no part in the idea.

The tough thing is to be able to fast charge and have the charger work properly in a situation where source power is interrupted often.

The idea of fast charging is having enough voltage and current to run a fast charger well enough. This normally means voltage higher than your batteries.

So, for example, you have 18v batteries, you would probably need 24v on the rails, to handle voltage losses by the charger.

So far no big problems or issues in the idea.

The show stopper is having a charger that can quickly recover from power interruptions and continue fast charging. This is well neigh impossible.

If you are fast charging, then this means a microprocessor based charger. These chargers typically apply voltage to the battery, then stop then measure the voltage and then start on a charging "curve".

The issue is that you would be interrupting this system so often it would basically never offer you fast charging.

So, you might say, ok, just trickle charge, with a circuit with a voltage regulator. This could be done, but the voltage to a battery needs to be controlled within one or 2 hundreths of a volt for a fixed regulator to work. This could be done, but it's not easy or cheap. Now the final kicker in this idea: as a battery ages, the terminal voltage for a complete charge changes... so the fixed regulator does not work.

If you charge to a lower voltage, then you no longer have fast charging, and also now your loco speed changes according to whether you are charging or not.

Basically no easy or good solution. The right solution would be a microprocessor based charger that "remembers" through a power interruption, does periodic recalibrations on charge state and progress, and restarts fast. While this is technically feasible, now the circuitry cost is higher and takes up space you could just use for more batteries.

Regards, Greg


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## Michael W (Oct 10, 2012)

Very good points Greg, i thought It might be feasible to use the gertbot (rasperry Pi) with motor controller board to regulate the charging and buffering the lot with super caps but after your i put I see that whilst in theorie a great Idea it is a bit like using cannons to shoot sparrows...
I think an easier option is to simply have a parked ng track on which I connect the charger via a jack port, I just need to find a battery pack that works in all my locomotives, either as a single pack or multiple thereof, so that I have one type of power supply system.... As it would be inside the locomotive I think I stay away from Li ion... Is there any configurations chemistries to be recommended?


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## Greg Elmassian (Jan 3, 2008)

With no interruptions in power, a small li-ion charger inside the loco would be effective with track pickups. 

So parking and charging for convenience would be, well, convenient. Something like a covered track, with a transparent top so charging status leds could be visible.

That would make sense I would think.

Regards, Greg


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## Totalwrecker (Feb 26, 2009)

http://www.batteryspace.com/nimhpacks24-48v.aspx

It's a suggestion, but Greg seems to be suggesting you back to lithiums.... 

Li-ions allow smaller packs than those above, but they bring a caution. In my larger loco it is removable, with my smaller loco the battery is in a water tender car attached by cables, also removable for charging. Some folks don't worry about it and seem to have good luck. I can't ..... afford to trust my luck.
Previously I had Nimh in the boiler, but there was a weight sacrifice vs the lead weight. After they died, I put the lead back in...
Keep us posted.
John


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## Greg Elmassian (Jan 3, 2008)

Sorry, whenever space is an issue, like where there is a lot of electronics taking up space, etc., I "shift" to lithiums.

Most failures seem to come from charging, and while I use track power on my layout, I use many rechargeable batteries, and am a firm believer in a thermal cutout in the pack.

Were I to use them in trains, I suspect I would have a balancing charger jack for extra safety when charging.

Greg


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## Michael W (Oct 10, 2012)

Thank you very much for the Link totalwrecker, and thank you for the idea of the thermal switch and balancing Jack Greg, is the thermal switch an add on to the pack or are there battery packs already prewired?
Kind regards


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## Greg Elmassian (Jan 3, 2008)

you can get packs with them, but you can buy them cheaply, mouser electronics and other electronic supply...

Greg


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## Pete Thornton (Jan 2, 2008)

Michael W said:


> . . .
> I think an easier option is to simply have a parked ng track on which I connect the charger via a jack port, I just need to find a battery pack that works in all my locomotives, either as a single pack or multiple thereof, so that I have one type of power supply system.... As it would be inside the locomotive I think I stay away from Li ion... Is there any configurations chemistries to be recommended?


I have been running NiMH packs in my locos for many years, but recently switched to Li-ion. It meant buying a separate charger, but the batteries are less than 1/2 the size of the ones I replaced. My Li batteries have protection PCBs in them, which prevent overcharging and shut down the battery pack if they get hot or the charge drops too low. (Can be irritating when your loco just stops and won't do anything until you plug it back in!) I got mine from All-Battery: Tenergy Li-ion 18650 11.1V 2800mAh Rechargeable Battery w/ PCB Protection and 22AWG Bare Leads (Built with Samsung Cells), Item #: 31493 Unit price: $34.99 USD


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## Greg Elmassian (Jan 3, 2008)

I think that buying the cells in a pack with those safeguards is smart, and also should instill enough confidence that, used with a good charger, make it so you don't need to remove the batteries to charge them.

Greg


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## East Broad Top (Dec 29, 2007)

I've been using the Li-Ion packs from All-Battery for the better part of 7 years now. The PCB protection has kept things in check very nicely. While my usual MO is to have the batteries easily removable for charging (typically by taking off a removable coal load or tender shell), I've got an increasing number of locos whose batteries are permanently installed. There's nothing in my experience which would so much as give me a moment's pause with respect to charging them. So long as you use the batteries and the recommended chargers, you'll be in good shape. 

Alas, that may not lend itself to charging on the track as you'd like to do. 

Later,

K


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## Greg Elmassian (Jan 3, 2008)

You could have parking spots that are actually the output of the charger.

And you put put a diode in the track pickups so it's "charge only", i.e. the battery cannot discharge through the rails.

Greg


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## Michael W (Oct 10, 2012)

I very much like this Idea Greg, i could use the siding(s) for this, they would be seperately wiried regardless, i could then use the central gertbot to supply chrging power to the rail, I just need to add afeature in the Locomotive to switch into charging mode...


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## Greg Elmassian (Jan 3, 2008)

so two ways: put the charger in the loco and power it from the rails... don't even need a switch, if it's not on the charging rails, the charger won't function, no power.

the other way, where the charger powers the rails, you can probably leave it on all the time, and it only draws significant current when there is a loco on the track.

The way I am thinking, no extra external switches, although you must have a master on off for the battery right?

Greg


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## Bill Swindell (Jan 2, 2008)

The only concearn is that if you expect the charger to act like most smart charger, that would mean that that the batteries would have to e connected to the rails. I wouldn't do that. 

Early on, we were going to put a constant voltage on the rails and let that feed to the battery. If the voltage were chosen properly, you would not overcharge the battery. I certainly would not do anything like this with Lithium batteries. In the ed, we never implimented the charge from the track idea. Most of our engines get about 6 hours runtime anyway.


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## Michael W (Oct 10, 2012)

Never thought of connecting the charger to the rails...., this might work on a charging track, i still would put an option to switch the locomotive into some form of safe/charging mode, this way I can additionally monitor the charging process through the raspberry pie and have an seperate emergency cut off.


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## Michael W (Oct 10, 2012)

Thank you Bill, 6 hours seems huge what battery packs are you running?


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## East Broad Top (Dec 29, 2007)

Michael, 6 hours is not at all uncommon from a 4800 - 5200 mAh Li-Ion pack, even on dual-motored locomotives. I usually get around 6 - 8 hours on my locos equipped with the high-capacity packs. The 2600 mAh packs I use in my removable battery locos give me between 2 - 4 hours run time. 

Later,

K


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## TonyWalsham (Jan 2, 2008)

If there was a reliable practical way of using the track for charging on board batteries, either running or stationary, no doubt someone would have already offered such a device commercially.
I have been doing battery R/C since 1985 and I know of no such devices. 
That should tell you something surely.


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## Michael W (Oct 10, 2012)

G'day to a fellow Aussie!
The track charging idea sort of overtook the main question, the battery Pack itself. Whilst I am happy to put in a charging jack, it sort of strikes me as adittional work (even if maybe somewhat easier and faster) when I already got a perfectly ok power pick up. Given the available run time of 4 hours as a base it might be a bit over the top, i kinda expected run times to be a lot shorter.
But irrespective of charging mode, what batteries would you recomment? The smallest locomotive is a Piko br80, i will require the space in the cap for the onboard computer, which leaves me with the actual body for power supply, given I would like 18 volts available to power everything, what would you recomment? Preferably battery packs I can run in multiples parralell so I use one style for all my locos.
Kind regards


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## Greg Elmassian (Jan 3, 2008)

Sounds like a few people did not read the entire thread, with the caveats about charger to the rail, etc. 


Please go back and read the discussion, the recent points were already brought up and discussed in an intelligent and circumspect manner.


If you can constrain your environment you can make some things work, we are talking about charging things on a dedicated "parking spot" like a dedicated siding.


Greg


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## Michael W (Oct 10, 2012)

The charging spot/siding would be the Ideal solution for me hence my thanks for your Input Greg.
I think the next step is to get a rasperry PI with Gertbot to have it control the Layout for straight DC control, this way I can build the Wifi control interface and learn to control the motors as well as programming an interface.
The gertbot can act as a straight dc controller or generate DCC, so when I change my locomotives to be directly controlled I can still have friends coming along for running Days and run straight DC or DCC whilst I can independently run each loco on Battery/wifi. The charging Track gives the added benefit of not having to deal with multiple charger lines and plugging things in.


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## East Broad Top (Dec 29, 2007)

If you are to have a dedicated siding for charging locos, you'll have to do one of two things. Either have a trackside charger feeding a short length of track where you park only one locomotive, or you energize the entire track with a fixed DC voltage, and have the charger itself onboard the locomotive.

I've not taken my smart chargers apart to figure out how large the electronics are specific to the charger itself, but when it comes to battery R/C installs, smaller is better, and having to find room in an install for an onboard charging circuit is going to increase the difficulty of installations, especially on smaller locomotives. That, and you're going to have to purchase and strip down the chargers to put them inside the locomotives. It's a lot of work and extra cost for little (if any) advantage. 

If you're going to have a dedicated trackside charger for each place where you park your locos, (a) that's a lot of chargers if you've got a lot of locos, and (b) at that point, just put a charging jack in the loco and plug it directly into the charger. That way you're not worried about power going through track pick-ups, etc. 

As I said above, I'm not going to tell you not to tilt at windmills. However, Tony's right on the money here. He and I have been doing battery power for decades. There's a distinct reason track-based charging has never caught on. I've got a roster of almost 20 battery-powered locomotives. I own two chargers. That's proven quite adequate to keep all my trains charged, ready to go at a moment's notice.

In all seriousness, if you're going to energize your tracks with a fixed DC voltage, skip the batteries. You want 18 volts; that's a lot of batteries (especially if you're going non-Li-Ion). That many batteries and an onboard charging circuit to go with it? You've just outgrown all but the largest of locomotives. If you're worried about dirty track, use a bank of super caps as a keep-alive. If you want a battery-powered loco to run at others' railroads, pick one and convert it, but for home use, I think what you want to do (and the limits you're placing on yourself) almost preclude batteries as a viable means to your desired end.

Later,

K


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## Greg Elmassian (Jan 3, 2008)

Jeeze, even asking nicely to read the thread because already discussed does not help. 



East Broad Top said:


> If you are to have a dedicated siding for charging locos, you'll have to do one of two things. Either have a trackside charger feeding a short length of track where you park only one locomotive, or you energize the entire track with a fixed DC voltage, and have the charger itself onboard the locomotive.
> 
> >>>>> yes already went there
> 
> ...


Kevin, I know this will just cause you to come back with a long diatribe with even more text... 

But you have seemed to come in right after me an parrot just what I said.

We went through all the problems with the simplistic idea that does not work, and narrowed it down, constrained the situation to where, withing these constraints, there are 2 methods that could work, given priorities.

Trying to do some thinking outside the box here, to see if there are some ways to make it work. 

Did you ever have something to do with Russian textbooks?

Just exploring the idea in ways it could work. Is it recommended for everyone? No. Can it work in certain circumstances? Yes.

Why are you just starting over hacking away at the idea? I already covered all the dangers earlier, we are past the negativity and looking for possible solutions. 

OK, lambaste away!


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## East Broad Top (Dec 29, 2007)

_"...we are past the negativity and looking for possible solutions."_

The "solution" to needing to top off batteries during operations is to use a battery technology that doesn't need to be topped off. Li-Ion batteries do that quite handily. Problem solved. 

With respect to older battery chemistries, as Tony and I have pointed out, there are no practical solutions for topping them off. It's not for lack of trying or "thinking outside the box." Many have tried, none have succeeded with any amount of demonstrable success. We've both been doing this for 30+ years; we'd know of a solution if there was one. 


Solution to charging batteries between operating sessions? Charging jacks on each locomotive. Time-tested, simple, and proven effective. Problem solved. 

If you don't want to go that route, you can use a charger connected to a dedicated section of track, and use the track pick-ups to get that power to the batteries. Problem solved, with two significant caveats. First, one loco per track. Second, loco must be pointed the proper direction to ensure proper polarity going to the battery. You could possibly use a bridge rectifier on the track inputs, but I don't know what that would do to smart chargers or peak-detector chargers. 

If you want to put constant DC on the rails to charge the batteries, the "solution" is to put a charging circuit on each locomotive. You can put multiple locos on the track, and a bridge rectifier would not impact the interaction between charger and battery. Again, problem solved, with caveats: the cost of and space required for each circuit in each locomotive. 

That's about as boiled-down as I can make it. Problems, solutions, and caveats associated with the various solutions. I'm not sure what more in the way of solutions you might be looking for. 

Later,

K


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## toddalin (Jan 4, 2008)

East Broad Top said:


> With respect to older battery chemistries, as Tony and I have pointed out, there are no practical solutions for topping them off. It's not for lack of trying or "thinking outside the box." Many have tried, none have succeeded with any amount of demonstrable success. We've both been doing this for 30+ years; we'd know of a solution if there was one.
> 
> Later,
> 
> K




Oh??? Here's one no one has mentioned...

With the advent of cheap electronics out of China, how about a boost circuit to provide and set the desired charge voltage from a lesser voltage that can vary. This was the principal behind the Phoenix "Big Boost."

With the ability to provide up to 35 volts and 3 amps, at just $3.89 each for three (less for more), this becomes an affordable option that could be adapted.


http://www.banggood.com/XL6009-Step...pply-Module-Converter-Regulator-p-916222.html


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## TonyWalsham (Jan 2, 2008)

Hi Todd.

That may be a start. You would of course have to add a suitable bridge rectifier with adequate filtering from the track pick ups.
The most important part would then be a miniaturised smart charger to take care of the various chemistries such a device may have to control. Probably would not need the above voltage booster as most smart chargers will work between 12 volts and 18 volts.
It can be done. Is it likely? I doubt it.


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## Michael W (Oct 10, 2012)

After I did some more research to see if I can use the Rasperry Pi to charge battery packs I found this: https://learn.adafruit.com/usb-dc-and-solar-lipoly-charger/using-the-charger
I can not see any reason why I can not use this setup with some supercaps to balance bad spots on tracks, when I read this it sounded like I can charge and draw simultanious... Need to think a bit more about the system, I had a good look at all my locomotives, it is challangng but possible to get everything in, the main issue is the gertbot board, if I use a standart motor controller board i should get the works for around $150 but I have a lot of python programming to do, if I can run it on a Pizero (which I still need to find out ) I will be happy be ause than we are talking full on board computer control for under $100.
Kind regards


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## Michael W (Oct 10, 2012)

Wow amazing find Todd, I could just run a 3.7 volt battery pack and up the voltage to lets say 16v for the motors, then I can use all the space to pump in amps, one simple multi pack charger setup and I can run the Pi off the same power supply. 
This becomes more intresting by the minute


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