# BATTERIES & MOTORS



## John J (Dec 29, 2007)

Ok I have been using cordless drill batteries for years. No I was thinking.

Are the motors we use in out trains bigger than what a drill motor is?

 Does the combination of the train motors make them larger than the Drill Motor?

Anybody got any correlation to this?

Should we run longer with train motors than if we were actually using a cordless drill. 


Also Anyone got a diagram on how to install Diodes if we parallel two batteries? 


Another Question 

Is there much differance between a 2.2 amphr battery and a 3.0 amphr battery 

Will I gain that much more run time with a 3 as compaired to a 2.2?


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## George Schreyer (Jan 16, 2009)

Drill motors are bigger and nastier than the motors that we use, at least the good drills are. Cordless drills usually operate under heavy load and the batteries take the brunt. Our train loads are usually not nearly that high. 

If you use two batteries of the same type, you can parallel them directly. 

a 3 aH battery will last 1.36 times as long as a 2.2 aH battery provided both provide the same voltage.


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## George Schreyer (Jan 16, 2009)

another comment. Paralleling works with lead acid, NiCad and NiMH but is not recommended for ANY lithium technology


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## John J (Dec 29, 2007)

Posted By George Schreyer on 12 Sep 2009 09:09 PM 
another comment. Paralleling works with lead acid, NiCad and NiMH but is not recommended for ANY lithium technology 
Oh George! Gald you told me that.....I did not know you could not parallel Lithium batteries.


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## Totalwrecker (Feb 26, 2009)

JJ, 

Gonna be ready for MARTY'S??? 

How many days? lol 

I hope you don't spend the whole time at the vendors....like I would be...lol 

John


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## Bill Swindell (Jan 2, 2008)

I believe that paralleling NiCad & NiMH batteries is not a good idea without isolating diodes in the circuit. Without them, large currents can flow when the batteries are connected in parallel.


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## John J (Dec 29, 2007)

Posted By Totalwrecker on 12 Sep 2009 10:53 PM 
JJ, 

Gonna be ready for MARTY'S??? 

How many days? lol 

I hope you don't spend the whole time at the vendors....like I would be...lol 

John 

I have only one piece of rolling stock coming with Mr and MRs Treeman. That should be it.


In another hour it will be 11 shopping days till Marty's


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## Totalwrecker (Feb 26, 2009)

Well that's good JJ, last I knew you were plannin' a battery car and such... 

OK... I remember the clues; Kidman's Trees and Trains? 

An outsider peeking in.... 

John


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## John J (Dec 29, 2007)

It is 2:18 AM on Sunday the 13th. I could not sleep so I started working on Rolling stock. I discovered something interesting. I can fit my new and improved Lithium Ion battery by Ridgid inside my baggage car. I also have two of the old Track Side Systems that would run only two trains. That fits in there as well. I will have to put a fan in the bottom so it will be cool inside. The third thing is I can light my cars too from there.


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## acmartina (Jan 6, 2008)

John,

Paul Norton has a good article on the OVRGS website on how to safely use two Li-Ion batteries in parallel (http://ovgrs.editme.com/Circuits) by adding barrier diodes in the positive leads. WHat is the definition of "safely"? I don't know, but it has worked for me. What I can say is that one Aristo battery pack gets quite warm under load from a SD45. Two in parallel stay much cooler. AristoCraft sells a harness with JST connectors, but you can easily make your own. I got the connectors and diodes from www.allelectronics.com. 

Goerge,
I am curious about your statement warning against parallel Li-ion batteries. I am not an expert of any sort on batteries (strictly a humble user!), but in my observation, parallel use of Li-Ion is actually quite common (maybe not smart?). If you look at the higher amp-hour battery packs used for other applications, they are all parallel construction (e.g. - http://www.batteryspace.com/, http://www.cordlessrenovations.com/). I don't recall seeing that so much in NiCad or NiMh (but I haven't really used them much). I do appreciate that Li-Ion batteries are more susceptible to problems if improperly constructed or used, so I try to stick with the higher-end name brand batteries. So far so good (knock on wood)! With all of the Li-Ion batteries in my life (cell phone, blackberry, laptop, ipod, power tools, etc), I reckon I've got more risk outside the trains!







But that is only my humble opinion! Thanks.

Steve H.
Cypress, TX


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## Greg Elmassian (Jan 3, 2008)

I've advised people paralleling battery packs to put a diode on the output of each pack, and to charge the packs individually. I see no additional danger with lithium ion packs over any other battery pack in this configuration. 

I've recommended this as long as Aristo has been selling their lithium ion pack, and there have been no reported failures from this configuration. 

Regards, Greg


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## George Schreyer (Jan 16, 2009)

if they are originally connected in different states of charge, this is true. If connected flat or fully charged, it's ok


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## George Schreyer (Jan 16, 2009)

Lithium batteries CAN be paralleled, but it is not recommended. The consequences of a fault are too severe. Lead-acid, NiCad and NiHM chemistries do not burn like Li chemistries do when a cell faults.


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## Randy Stone (Jan 2, 2008)

A question regarding battery life. 

For those of us that don't get to run our trains everyday or sometimes not even in a month. How do the different types of batteries hold up when not used for extended time frames? Do they need to be kept charged up? what happens if they're left to sit for a couploe of months? 
With my Nicads in radio controled Electric cars back in the 80s and 90s, they would build a memory and it could be at half charge level if not recharged correctly. With the RC cars, I was racing once a week and testing at home at least once a week, so the batteries were in use quite often. With my Dewalt cordless drill, it can sit unused for weeks and it still has a good charge and operates just as if it was being used everyday. 

This Ridgid battery JJ is talking about, is it basically the same as the Dewalt battery? Can I expect it to perform like my Dewalt? 

Also, my Dewalt is a 14.4 volt. I know there are others that are 18 volt. So long as the battery fits in either a passenger car or box car, is there any reason you wouldn't want to use the 18 vold in place of the 14 volt? 

Randy


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## Greg Elmassian (Jan 3, 2008)

Lithium-based chemistries have better "shelf life", i.e. they have a lower rate of internal self discharge. 

Nicads and nickel metal hydrides have greater self discharge rates. 

Gel cels can be somewhere in the middle, but they are usually designed to get a constant float charge, used as standby batteries in emergency lighting, for example. 

Regards, Greg


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## George Schreyer (Jan 16, 2009)

I'd rerank that from best to worst for batteries that are NOT new but are otherwise in good condition 

1> Lithium 
2> Lead Acid 
3> NiCad 
4> NiMH 

Depending on the condition of the battery, the lead-acid can have bad shelf life if it is partially sulfated. The main failure mechanism of both NiCad and NiMH is leakage (different mechanisms, but the same result). At end of life, the batteries can leak so fast that they appear to not take a charge.


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## acmartina (Jan 6, 2008)

I agree wholeheartedly with your words of caution around Li-Ions, George. Users should beware and be careful! All battery chemistries listed have application for our trains and have their pluses and minuses for sure. I prefer Li-Ion for the following reasons (and I accept the associated risks with eyes wide open) - [*] Shelf life between charges, as noted above - I can recharge after use, rather than having to charge in anticipation of use, [*]Compact size per Amp-hour - they fit in tighter spots (e.g. 14.8v Li-Ion pack (4 cells) bundled in a square will fit under the short hood of the Aristo RS3 - take the screws off the short hood and its easy removal for charging in a safe place). [*]No "memory" issues like NiCad and NiMh. Li-Ions have a finite number of charges in them, and there is no slow fade when the do die, but they are consistent. [/list] In any case, whatever you choose, above all else, be informed and be safe. That doesn't mean don't accept risk, but be sure you understand it and mitigate it appropriately before taking it on. Happy railroading, whatever you choose! 
Thanks,
Steve H


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## Greg Elmassian (Jan 3, 2008)

I found some of the newer car battery chargers use a high frequency signal to break up and reduce sulphation. The one I have even has a desulphate setting that takes about a day and a half to condition a gel cel. It has settings for gel cels, sealed, and non-sealed lead acid batteries, and a 2/10/20 anp setting. Made by Vector. 

Regards, Greg


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## George Schreyer (Jan 16, 2009)

Steve, 

All those reasons are good ones for using Lithium chemistry batteries 


The downsides should be listed too.

- higher cost
- highly reactive materials (when upset badly enough, these batteries will burn fiercely)

Lead-acid has downsides
- big
- heavy
- highly corrosive if they leak 

- environmentally weak (lots of lead inside)
- rapid failure if discharged and "put away wet"

- not so cheap anymore....

as do NiCad and NiMH

- not cheap either
- get leaky with time (NiMH is worse)


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## Randy Stone (Jan 2, 2008)

ok, now JJ talks about his new and improved Lithium Ion battery by Ridgid, but what is the part number or model number? 

Is this it? 
Ridgid 24 Volt 3.0 Ah LI-ION Battery 130377001. 
Get more power and run time from your Ridgid Drill by replacing the battery with a new Genuine Ridgid battery. 
Ridgid 130377001 24 Volt Li-Ion Battery for 24 Volt cordless tools. 
Ridgid 24 Volt 3.0 Ah LI-ION Battery 130377001 (E183634) Use with charger number 140315001 

Price listed on the website is $179.00. Is that right? 

If so, the website shows a 1 year warranty. I thought Greg said something about a lifetime warranty


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## Randy Stone (Jan 2, 2008)

Home Depot has this one for only $99.00 


RIDGID 18V 3Ah Lithium Battery 

Model # AC46182 Internet/Catalog # 100618264 
Store SKU # 737681 

$99.00/EA Each


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## Greg Elmassian (Jan 3, 2008)

There is a lifetime service agreeement on the batteries and parts of the tools. You REGISTER the tool and batteries, and then if they fail you send them back or go to an authorized service center. No one else has warranties that include batteries. Further questions will cause me to tell you to Google it, or read the sign at the Home Depot. 

Greg


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## Randy Stone (Jan 2, 2008)

ok so there is a life time service agreement on the Ridgid batteries. Most of the sites I visited only listed a 1 year warranty. Home Depot says to call about the warranty. Seems to me they would all be listing a lifetime service agreement as a great selling price.

What voltage battery are we talking about using? 14, 18 or 24? 

Or is the voltage up to the user? 

Which will run a train the longest if the same train is run at the same speed? 14 volt or 18 volt 

It would seem to me that you would want the 24 volt (Asuming it fits where you want to put it) even if you're only pulling 14 or 18 volts.


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## TonyWalsham (Jan 2, 2008)

Randy. 

Run time depends on the capacity of the battery not the voltage. 

Think of it as capacity being the amount of gasoline in the tank. The more gasoline the longer the engine will run at the same speed. 

Think of voltage as being the octane rating. The higher the octane, the more power to overcome the load holding the car back and thus a higher speed.


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## John J (Dec 29, 2007)

Well I went to Homeous Depotis and bought a one Ridgid 18 volt 3 am hr Lithi Ion battery and a charger. What I discovered so far is that it will fit in all my battery cars.
It will also fit in my baggage car for my strealiner. I am using those old metal cased Track Side recievers. That too will aslo fit in my Baggage car. But I also think I can put the reicever in my "B" unit Now I will be bale to light my cars and run my trains.

Friday the 18th in payday I plan to get two more Ridgid batteries 

I hope they last longer than my Chicago Electric batteries .


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## rmcintir (Apr 24, 2009)

The size of the Ridgid battery is great since it doesn't have the long neck plug. I am going to look at them.

Another battery option which might just be able to squeeze into a large box car is this battery on woot right now:


Woot has Energizer XP18000 Universal 18000 mAh Portable Battery Back and Charger for $99 today (9/14/09) 

It's $99 for one day only. 

http://www.woot.com 


They have huge battery power, 18000 mAh. I have no idea how well this would work for trains but I have seen them used for personal robotics applications.


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## Greg Elmassian (Jan 3, 2008)

Actually, with PWM output, the amp hours of the battery times the voltage is the "fuel tank"... consider running a 12 volt battery at 100% duty cycle (your pwm is full on)... the loco gets 12volts... now consider a 24 volt battery at 50% duty cycle, the loco will effectively get the same voltage... 50% duty cycle, but double the voltage. 

So in this situation 1 amp hour of 12v would equal 1/2 amp hour of 24 volts. 

For each battery: (12v) 1 times 12 = (24v) 1/2 times 24 ... both cases using the same power, volts times amp hours = watt hours... 

So, 24 volt battery of amp hour "X" would give you twice the run time of a 12 volt battery of the same amp hours. 

All modern motor drive circuits I know of are PWM, so this is true for most cases...

Regards, Greg


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## TonyWalsham (Jan 2, 2008)

Greg. 
1. The problem that occurs is the 24 volt supply will provide way too much top speed if 12 volts was adequate. 
2. The excess voltage is burnt off, as in wasted, in the form of heat by both the logic supply circuit and the output drive. 
So, whilst in theory you are correct, in practice because of # 2, it is certainly not double. 
Plus the heatsinking capability of the voltage regulator circuit likely has to be increased which makes th ESC larger. 

The bottom line is that it is always better to increase the run time by increasing the battery capacity and leave the voltage at whatever provides an adequate top speed.


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## Greg Elmassian (Jan 3, 2008)

1. 1 volt would be about 1/24 th duty cycle right? 4%? That is certainly doable... 
2. nope, not at all, that is why people use PWM 

The heatsinking of a series voltage regulator to drop down the 24v would be affected, but it's just the logic part, which should be much lower current, so it should not be a big deal, depends on how much current the logic circuit takes, but yes, I agree a higher input voltage is a design negative here, as long as you use a linear regulator. More people are using switching regulators for their logic side to avoid this problem. 

Yes, given all other things equal, I would pick a battery voltage that just allows the top speed desired at almost max throttle. 

I incorrectly read your previous post, I, for some reason, thought you stated something else about amp hours and run time. 

Regards, Greg


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## Randy Stone (Jan 2, 2008)

ok, so what voltage do different brands of trains need? 

I believe the LGB need a higher voltage than say Aristo Craft. 

The AG990 has a max out put of 22 volts 

My MRC6200 has 18 Volt output, but the mode button has to be in the right position for the LGB trains to run well. What exactly the mode button does, I'm not sure, but if it increases the voltage, then it would seem that I would need more than the 18 volt pack to run LGB trains. 


Well I found the following online. The Mode switch really isn't a boost to 18 volts but a lower voltage setting for N & HO Scale


[*]Power on-off switch[*]Direction control switch[*]Overload protector[*]Power monitor lamp[*]INPUT: 120VAC 60Hz[*]OUTPUT: Mode 1 0-18.5VDC 18VAC --- Total Output: 60VA[*]OUTPUT: Mode 1 0-14VDC 18VAC --- Total Output: 52VA



Randy


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## TonyWalsham (Jan 2, 2008)

Greg. 
If you burn energy you generate heat. 
In a linear output circuit, the heat is generated in the ESC and thus requires adequate heatsinking. 
In a pwm output circuit, the heat is generated in the motor(s) and is the main reason why LGB said not to use pwm. Their motors were not very well ventilated. That is why AristoCraft, for example, ventilate the motor cases. So the heat can be dissipated more easily. 

Now whilst I cannot explain the theory, from practical experience I know that is what happens.


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## Randy Stone (Jan 2, 2008)

Along this heat issue, it would seem to me that pulling 18 volts from a a 24 volt battery would heat it up a lot less that pulling 18 volts from an 18 volt battery


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## TonyWalsham (Jan 2, 2008)

Randy. 
It is to do with the duty cycle of the pwm. 

The batteries can, but, in most cases do not get hot, no matter what the battery voltage is. 
Apart from th voltage regulaton circuit and depending on what the load is, it is either the ouput drivers or the motors or a combination of both that get hot. 
18 volts coming from 24 volts means the pwm circuit is running at 75% duty cycle. 
When a pwm output is running at 75% there is some heat to dissipate. 
When a pwm output is running at 100% there is very little heat to dissipate. 

It is like turning a light switch on. Assuming there is no resistance in the switch 100% of the voltage is passed through. If only 75% is required, via a dimmer switch, the excess voltage has to be dissipated in the form of heat. That is relatively easy to do with AC mains voltage. Less easy to do with our low voltages. Especially as we are working with DC and not AC.


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## barnmichael (Jan 2, 2008)

A 24 volt battery puts out 24 volts, period. You do not draw 18 volts from a 24 volt battery. The voltage source is constant (not counting, of course, the fact that when the battery nears discharge, the voltage will drop, but that does not pertain to this discussion). Now let's skip the electronics for a second and look at the motor. The motor consists of windings in a magnetic field. You have a fixed magnetic field in the housing and as voltage flows through the coils in the armature, the magnetic field builds and the fields attract and repel as magnetic fields do, causing the motion which results in armature rotation to the gears which runs the train. Different manufacturers make various types of motors. They can vary in armature friction, size of wire, number of windings, etc. The motor basically presents a fixed resistance to the electrical circuit. Electronics is governed by Ohms law which states that given a fixed resistance, the current is directly proportional to the voltage. There are three components of a circuit, current (I), voltage (E) and resistance (R). Ohms law is represented as E=I x R. Now those algebra classes you took so many years ago can finally come into play. So, voltage equals the current flowing through a resistance. By the same token, I=E/R and R=E/I. With this knowledge, we can make a circuit that has a certain amount of resistance, apply a certain amount of voltage and it will draw a certain amount of current. Let us picture five resistors hooked end to end (a serial circuit) and then to our voltage source. If we measure the voltage at both ends of our string, we get our source of 18 volts. But if we measure between resistors 2 and 3, we will get a lower voltage. 

We'll skip all the physics of magnetic fields and just say that the motor is basically a fixed resistance, which means the current draw will be related to the voltage. The manufacturer builds the motor and says that at a certain voltage, the motor will turn a certain RPM. As you vary the voltage, the RPM will change accordingly, as will the current. 

Okay, now for the electronics in the middle. Your source voltage is going to be constant. If you have an 18 volt battery, you will always have 18 volts coming out of that battery. Your motor will turn a certain RPM based on voltage. Since we want to travel at different speeds, we need to vary the voltage to the motor. Remembering Ohms law discussed above, we see that by varying our resistance, we can get a different voltage to the motor, hence a varying speed. 

This is where our ESC comes in. We use the ESC (Electronic Speed Control) to create a varying resistance, which allows a varying voltage to the motor. So we apply 18 volts to the input, the ESC varies its resistance sending the desired voltage to the motor for the speed we want. If we're going slow, we maybe only sending 8 volts to the motor, so the ESC uses the other 10 volts and dissipates it in the form of heat. But what if we change to a 24 volt battery? The motor still only wants 8 volts, so now the ESC has to "throw away" or dissipate 16 volts instead of 10 volts. More voltage, more current. The flow of current through a pure resistance generates heat. So, more current equals more heat,, which has to go someplace. That is why the ESC gets warm and needs that big finned chunk of aluminum known as a heatsink to dissipate the heat. 

Current is measured in amps. you will see batteries labeled like 500mAh or 1000mAh or 1800 mAh gives you the capacity of the battery. The term mAh means milliamphour, (milliamp is one thousandth of an amp) which is what the battery will supply over an hour. If your motor draws 500ma, the 500mAh battery will run for an hour. With the same motor, an 1800mAh will run for about 3 1/2 hours. 

What all this boils down to is, you need to know what voltage will run your train at your desired speed. If 12 volts runs your train at the desired speed, then a 14 volt battery (the electronics need a little overhead to function properly) will be all you need. An 18 or 24 volt battery will not gain you anything. On the contrary, your ESC now has more voltage to "throw away" and the hotter it gets. 

Once you know what your desired voltage is, you want the highest capacity battery in mAh you can fit into the allotted space. You want to increase your available mAh, not the voltage. 

This might seem like a lot of info, but it only scratches the surface. Many things can further complicate things like PWM, inductive reactance, magnetic field physics, etc. But all that is frosting. The basic points of how much voltage your engine needs and the largest capacity battery you can fit in are still the key points and always valid. 

This probably raises more questions than it answers, but you'll get the idea.


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## Mike Reilley (Jan 2, 2008)

Posted By barnmichael on 14 Sep 2009 07:26 PM 
.... Okay, now for the electronics in the middle. Your source voltage is going to be constant. If you have an 18 volt battery, you will always have 18 volts coming out of that battery. Your motor will turn a certain RPM based on voltage. Since we want to travel at different speeds, we need to vary the voltage to the motor. Remembering Ohms law discussed above, we see that by varying our resistance, we can get a different voltage to the motor, hence a varying speed. 

This is where our ESC comes in. We use the ESC (Electronic Speed Control) to create a varying resistance, which allows a varying voltage to the motor. So we apply 18 volts to the input, the ESC varies its resistance sending the desired voltage to the motor for the speed we want. If we're going slow, we maybe only sending 8 volts to the motor, so the ESC uses the other 10 volts and dissipates it in the form of heat. But what if we change to a 24 volt battery? The motor still only wants 8 volts, so now the ESC has to "throw away" or dissipate 16 volts instead of 10 volts. More voltage, more current. The flow of current through a pure resistance generates heat. So, more current equals more heat,, which has to go someplace. That is why the ESC gets warm and needs that big finned chunk of aluminum known as a heatsink to dissipate the heat. 




Ok...what's above is WRONG. The idea is right...but the explanation is not right. Modern ESCs do NOT work based on controlling the voltage to a motor. They work based on controlling the energy fed to a motor. They do this by chopping the battery's constant voltage into short pulses. The longer the pulse...the ON state...means more time the current gets to the motor. Shorter pulses from the battery supply being chopped into pulses means less time the current gets to the motor. Ohms law applies...but NOT as described. When the pulse is ON...the motor resistance determines the current draw. When it's off, there's no current flow. The amount of energy being provided to the engine is the product of the voltage applied, the current the motor pulls, and the amount of time the ESC pulse is in the ON state. For a well designed ESC, the voltage the motor sees is very close to the battery voltage when the ESC pulse is ON. The motor sees nothing when the ESC pulse is OFF.


The power the motor can develop is directly related to the energy fed to it. The power the motor generates , given the load it is experiencing, is what determines the speed of the engine. So....to make an engine accelerate, you give it longer pulses. To slow it down, the ESC gives it shorter pulses. The motor actually integrates the on and off times to result in a power level that it can provide. 


The heat generated within the ESC is only the result of the chopping...which is an on/off kind of thing. There is no SINKING...as in resistance....being applied by the ESC. They get hot from switching high current...and it's not really that hot for trains as compared to RC cars. They do NOT get hot because they are "dissipating" energy that isn't being used.


Motors running at slow speeds do not cause the ESCs to get hot, because they are switching low current loads. Motors running at high speed...train motors...cause the ESCs to be warmer. But...if you've ever run an RC car...pulling 30 amps in it's motor...HOT is another kinda thing to deal with...and LARGE heat sinks are needed to keep the switching transistors from frying because when in the ON state...they are passing 30 amps through them.


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## TonyWalsham (Jan 2, 2008)

Michael from Texas is describing how a linear output controller works. As such he is correct that the ESC dissipates the heat via an adequate heatsink. 
To the best of my knowledge there are only two linear output ESC's made for Large Scale trains that can be used on board. 
The trackside Crest TE (sans case) and the TITAN-10 I make. Both have to have quite large locos or box cars as they each have large heatsinks. 

Mike Reilley is correct that most modern ESC's use pwm ouput for precisely that reason. 
In the case of PWM it is the motors that dissipate much of the heat. How much heat does depend on the frequency of the PWM, among other factors.


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## barnmichael (Jan 2, 2008)

Okay, I am new in the hobby and have not yet looked deeply into the present technology being used in Large Scale trains. If you had read the entire post, paying special attention to the closing statement "This might seem like a lot of info, but it only scratches the surface. Many things can further complicate things like PWM, inductive reactance, magnetic field physics, etc. But all that is frosting. The basic points of how much voltage your engine needs and the largest capacity battery you can fit in are still the key points and always valid." Notice I specifically mentioned PWM was not covered as it was not germane to the discussion. The topic's primary points and questions were regarding using 18 or 24 volt batteries and how much voltage was used, etc. In the explanation of the relationships between voltage, resistance and current, everything is accurate and really how it works. 

In the small DC motor industry, fine control at low speeds was difficult with a linear supply as the low voltage resulting in minimal magnetic fields with in the motor gave erratic operation. By increasing the voltage and using varying pulse widths, created a much larger magnetic field, which gives much finer low speed control. Depending on the usage and the particular development engineer, the voltage may vary with the desired speed. There would be a minimum voltage (probably around 6-10 volts depending on the motor design) used to get the motor running at low speed. As increased speed is requested, the pulses get wider and the voltage gets higher. There will likely be a point at which the switching or pulses stop and pure DC is being fed to the motor. Regardless, the current path through the voltage controlled regulator, is basically the same whether linear or PWM is used. In a linear system, the control circuitry applies a varying control voltage to the VCR. In a PWM system, the control circuitry still supplies a varying control voltage is sent to the VCR, but it is also pulsed by the more sophisticated control system. Again there are three components to a circuit, voltage, current and resistance. As I stated, the controller controls the voltage to the motor. For the purposes of that discussion, whether that voltage was continuous or pulsed was immaterial. There is no component of an electronic circuit called energy. Energy is a component of the physics side of things and is a measure of power. Energy is a product of an electronic circuit when current flows through a resistance. Energy or power is directly proportional to the voltage times the current or P=IxE. 

The VCR in an ESC is essentially a variable resistor that controls the voltage going to the motor, either switched or continuous. Ohms Law applies as it always does. The voltage supplied to the motor draws current. The more voltage applied, the more current flows. In a series circuit, the current is the same through all components. Current through a resistance creates heat. The more current, the more heat. The heat produced is proportional to the current supplied. But heat is also kind of cumulative. If you fire up a propane torch and move it back and forth over an object, that object has time to dissipate some heat to the air in between passes. However, if you hold the torch steady on the object, it gets very hot and reacts appropriately to the heat (melts, burns, etc.) If you have very short pulses as in low speed, the heat sink has a chance to dissipate the heat between pulses. 

Essentially, Mike said the same thing I did. He simply added the distinction of the pulsed voltage versus continuous voltage. His terminology is not totally correct but his description of the process is basically correct. 

The technology of variable pulse width dc voltage was developed to provide fine control and better performance of motors at very low speeds. The fact that the circuit doesn't generate as much heat is a side benefit, but not the reason for developing technology. 

But none of this has anything to do with the original question of whether using a 24 volt battery would improve performance over an 18 volt battery.


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## Bill Swindell (Jan 2, 2008)

Randy, my experience is that LGB & USA engines generally run nicely with 14.4 V batteries. The Aristo engines need a little more voltage to run the same speed as the previous 2 brands.


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## Mike Reilley (Jan 2, 2008)

Posted By barnmichael on 14 Sep 2009 10:59 PM 

The VCR in an ESC is essentially a variable resistor that controls the voltage going to the motor, ... The voltage supplied to the motor draws current. The more voltage applied, the more current flows. In a series circuit, the current is the same through all components. Current through a resistance creates heat. The more current, the more heat. The heat produced is proportional to the current supplied. But heat is also kind of cumulative. If you fire up a propane torch and move it back and forth over an object, that object has time to dissipate some heat to the air in between passes. However, if you hold the torch steady on the object, it gets very hot and reacts appropriately to the heat (melts, burns, etc.) If you have very short pulses as in low speed, the heat sink has a chance to dissipate the heat between pulses. 

Essentially, Mike said the same thing I did. He simply added the distinction of the pulsed voltage versus continuous voltage. His terminology is not totally correct but his description of the process is basically correct. 



I understand you're new...and welcome aboard....but you still don't have the physics and electronics explanation quite right....and I'm not trying to be pissy...just explanatory. In the MODERN world...ESCs are NOT like variable resistors. They're just energy switches...or power switches if you like that word. Modern ESCs regulate how much energy can get to a motor...using the chopping technique. The energy comes from the battery. The motor generates the power. The ESC is in the middle to regulate the amount of energy that gets to the motor...so it can develop power. That's the distinction...and, frankly, it's not a big issue..the energy vs power argument. 

Modern ESCs do NOT act like a variable resistor...because that explanation means that the ESC absorbs power...and they don't really. In the OFF state, they aren't absorbing anything...they're off...an open circuit is the better analogy for the series circuit between the battery and the motor. When you use the term "variable resistor"...like Tony says...you're really talking about a linear amplifier. Modern ESCs are NOT linear amplifiers. They are switches. It's the motor that integrates all the pulses of energy and generates power. The Power = voltage times current is true in DC...but when you introduce pulsed power...it's more complicated to explain...and Ohms Law arguments, while valid, are actually too simplistic. All modern ESCs use chopping techniques to regulate the amount of ENERGY that can flow. The load...a motor...a light...a vacuum cleaner...integrate the amount of PULSED energy to prove POWER. 


The world of ESCs began with literally a variable resistor...a wire wound potentiometer with a slider run by a servo. My first RC car had that setup. Next step was to replace the servo actuated, wire wound potentiometer with an electronic circuit board...actually an amplifier design...that did the same thing as the potentiometer...it varied the voltage to the motor. And those early "linear ESCs" burnt out all the time...because they absorbed too much energy...because they had to allow HIGH currents to pass at low voltages to get a motor (under load) running. And in passing high currents, the amplifier DID absorb power...energy. I mean, who want's a speed controller that sucks up his battery?? Then the pulse width design came into play. Tony calls it Pulse Width Modulation...PWM...and that is still the dominant design. Modulation means to vary under control...and modern ESCs modulate (control) with width of the ON pulse to control the energy flow. Until Tony told me, I didn't even know that someone still made the middle version...called linear ESCs. They're totally obsolete IMHO.


And you're right....this has nothing to do with battery voltage.


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## TonyWalsham (Jan 2, 2008)

Hey JJ. 

That will teach you ask a simple question.

Mike, the TE is arguably the single most popular on board battery R/C ESC of all time, and I believe is stll used by more Large Scalers into battery R/C than anything else. 
Granted they are way too big for most "in the loco" installations but they are reliable and when run in Linear mode, are quite safe for pretty well anything you might like to name.
It, and the TITAN-10 I make, are still the only ESC's made that you can reliably use with some sound systems and DCC equipped locos in DC mode.
That is not to say PWM is not becoming the dominant method of controlling motors. I make them as well. However, for some situations they are still the best method of control especially where space is not a problem.


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## John J (Dec 29, 2007)

All I wanted to know is. ARe the motors in my trains bigger or smaller than what is in a Cordless drill. And do they draw less curent. There fore thay should run longer on my cordless drill batteries than the drill it's self. I use to know all this stuff when I had to trouble shoot down to the componet. ( Back in the 70's ) NOw all I do is change out the board and someone else fixes it. ( And he don't do a very good job of that)


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## Greg Elmassian (Jan 3, 2008)

The first response to your question, by George Schreyer answered that question. I will second everything he said as valid in my experience. 

Regards, Greg


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## TonyWalsham (Jan 2, 2008)

Greg, 
Do you really believe it is a good idea to parallel batteries without protection Diodes? 

No mention of diodes in this, "If you use two batteries of the same type, you can parallel them directly". 
.....and again with this "another comment. Paralleling works with lead acid, NiCad and NiMH but is not recommended for ANY lithium technology"

By not qualifying those statements that a diode should be added, I believe that is what George was intimating?


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## Torby (Jan 2, 2008)

Your train likely draws less current than your cordless drill while you're actually drilling something.


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## Greg Elmassian (Jan 3, 2008)

I was probably the first person on the Aristo forum to insist that all paralleled packs use a diode on one of the outputs, the positive one to make it simple. 

There were lots of arguments from people who never had a problem, especially since Aristo made a "Y" cable. Now on that forum everyone believes in the diodes except for a few. 

I've always said to use them... 

The danger, as you well know, is if a pack has a cell fail, then the other pack can actually overcharge it and cause a problem. 

My personal belief is to always do the safe thing, I always recommend diodes. 

Regards, Greg


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## barnmichael (Jan 2, 2008)

There is no such thing as an "energy switch". The device being used is normally known as a voltage controlled regulator. It has an input (from the battery), and output (to the motor) and a third lead is the control lead to which a voltage is applied that determines the output voltage of the device. Now that can be a varying voltage providing a varying voltage output, or it can be a constant voltage providing a constant voltage level output. This control voltage can be continuous as in a "linear" supply or the control voltage can be pulsed or switched to provide a "PWM" output. Technically, both terms are quite incorrect for what is happening, but they seem to be commonly used in the hobby. 

I may be new to the hobby, but I am not new to electronics. And electronics work the same whether they are used in a model train, in a manufacturing plant, in a public service dispatch console or anything else. I have been a technician in electronics for 40 some years. I have taught basic electronics and advanced specialty electronics in vocational schools. I have designed, built and maintained sophisticated multi operator dispatch console systems. I have maintained and repaired radios from little walkie-talkies to 10,000 watt shortwave radios for world-wide communications, including interfacing with the White House Communications Agency for supporting Air Force One and other Special Air Missions, to 100,000 watt FM broadcast stations. I built three radio stations from the ground up, including all of the studio and console equipment, the satellite systems, automation systems, the transmitters and antennas and all other related electronic needs. I am currently the Technical Director of a major radio network. I maintain twelve satellite channels, all of the associated control equipment as well as the studios used by nationally syndicated talkshow hosts. Our system provides programming to over 2000 radio stations around the country serving many millions of listeners. 

In other words, I know a little bit about electronics and the theories behind it. BTW, modulation means the integration of intelligence onto a radio frequency carrier wave. There are a variety methods to modulate a signal, AM, FM, FSK, AFSK, PSM,Video, PWM, QPSK and many others. Modulation does not control anything. 

We are not contradicting each other. The process we are describing are basically the same. There is some inaccurate terminology used. There is a failure to understand the basic laws of electronics and how current flows through series and parallel resistive circuits. 

It's not really anything to get wrapped around the axle about. It's a box and it works. Determine the voltage and current requirements and limits of the motor and the ESC and utilize a battery to meet that need. A higher voltage battery does not increase capability and, in fact, may decrease capability due to the higher heat levels generated compensating for the higher voltages.


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## George Schreyer (Jan 16, 2009)

all these battery chemistries are routinely run without diodes in larger series-parallel battery assemblies for automotive use. 

The thing that you have to be care with is that all of cells are in the same state of charge when initially connected. Even a single cell is really a parallel combination of many elemental chunks of material which are effectively in parallel. They were manufactured together and so tend to keep the same state of charge UNTIL one part of a cell starts to degrade. We cannot see the individual pieces of a cell diverge from each other, but this is what happens. The cell gets worse and worse as this progresses. 

diodes are helpful for batteries that are NOT in the same condition so that one battery cannot try to recharge the other one. This is often done in RV's between dual house batteries because often one will fail and be replaced. Then the two batteries will not match and cannot be safely paralleled.


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## Randy Stone (Jan 2, 2008)

Thanks for the info Bill. 

I'm quite surprized as I always thought LGB needed more power and had always heard that USAT had a higher amp draw. 

Randy


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## barnmichael (Jan 2, 2008)

Posted By John J on 15 Sep 2009 05:50 AM 
All I wanted to know is. ARe the motors in my trains bigger or smaller than what is in a Cordless drill. And do they draw less curent. There fore thay should run longer on my cordless drill batteries than the drill it's self. I use to know all this stuff when I had to trouble shoot down to the componet. ( Back in the 70's ) NOw all I do is change out the board and someone else fixes it. ( And he don't do a very good job of that) 
There is a large variety of motors, so that question can only be answered on a case by case basis. In a perfect world, you could obtain the manufacturer's specs as to rpm and current draw for a given voltage for each motor and comparing them. Otherwise, you need to do it the hard way. You have to take the item apart and physically measure the motor if you want to. Then you need to apply voltage to the motor with an ammeter in series and measure the current draw. Yes, there are clamp type ammeters that can be used, but some of them don't do well with DC.


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## Greg Elmassian (Jan 3, 2008)

Most pwm circuits use mosfet switches for the output. The way they do not have to have huge heat sinks like a linear control is that they are either basically on or off. In the off state, virtually no current flows, in the on state, they have very low resistance, thus very little voltage drop and no heat. 

They are correctly called mosfet switches. Modern controllers control the speed as if someone was turning a light switch on and off rapidly... longer "on time" is more light, or in our case, more power to the motor. 

These mosfet switches are really transistors.... Metallic Oxide Semiconductor Field Effect Transistors... MOSFET.. 

Regads, Greg


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## TonyWalsham (Jan 2, 2008)

The edges of the waveform also have to be nice and sharp. Otherwise MOSFET's can overheat.


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## John J (Dec 29, 2007)

Here is what I ended up with.

I got Ridgid 18 volt 3 am rh battery and got a charger for it. 

I just hooked it up to my Old Style TE that can run 2 chanels.

The battery charge up to 20 volts.

I ran my Aristo F A&B units and the ran very well. On a run Stand. 

Looks like they will go at a fast clip.

Right now I am happy.

See you at Marty's in8 days.


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## TonyWalsham (Jan 2, 2008)

JJ, I am very happy you are happy.


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## Ron Senek (Jan 2, 2008)

JJ 
Watch your batteries when running and don't let them run completely out of charge as they won't recharge if they get too low. 
I use the same batteries and have had that problem. Just have to stop BSing and pay more attention!


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## Greg Elmassian (Jan 3, 2008)

I wonder if there is low voltage cutoff in the pack? I would think there would be in a detachable battery. 

Let us know how it goes. 

Regards, Greg


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## Totalwrecker (Feb 26, 2009)

Economics would put the low voltage cut off with the motor... 1 there vs 1 ea for every battery. 

Maybe the reason Ron found out the hard way.... 

John


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## John J (Dec 29, 2007)

This sucks. Should I go by a Ridgid cordless drill and gut it for the cut off circuit? Maybe I will just got back to ni cad. They are less trouble.


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## barnmichael (Jan 2, 2008)

The cut-off circuit is typically part of the ESC. A cut off is easily made with a Zener diode of the desired cut-off voltage a resistor and capacitor making an RC filter to keep out engine noise. A generic isolation diode keeps things moving the right direction. When the voltage drops below the desired amount, the Zener opens. That will allow the other end of the generic diode to go almost to ground. Connect that to one of the drivers for your control switch (power transistor, FET, MOSFET, etc.) and it will effectively kill power when the battery gets down to a certain point. 

Of course there are many other ways to accomplish this as well. Most ESCs have this feature built in but since the TE was originally designed to use fixed power trackside, it wasn't needed. It should be an easy feature to add, though. The hardest part of the whole operation is finding a schematic of the TE and deciding where to shut it down. 

Otherwise, just keep a close eye on your train. When it starts getting sluggish, it's time to charge/change the battery.


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## Totalwrecker (Feb 26, 2009)

How about a circuit that detects low voltage approaching and rings a bell to get JJ's attention? 
That way he won't have to climb up on Marty's big bridge to change the battery! 


John


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## Greg Elmassian (Jan 3, 2008)

JJ, someone made a comment: "Economics would put the low voltage cut off with the motor... 1 there vs 1 ea for every battery. " 

I will make a comment: "safety and fear of being sued would put the low voltage cut off with the battery, like laptops do" 

Both of these statements are true from the standpoint of logic. 

Neither John or I KNOW for sure. 

Run your train and see if it just gets slower and slower, or suddenly shuts off like the Aristo LiIon pack. 

Regards, Greg


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## rmcintir (Apr 24, 2009)

Based on what the Home Depot ads say, the low voltage protection must be in the battery. I conclude this because the Home Depot ad states, "Fits all existing 18V Ridgid tools (Ni-Cad or Lithium)."


Home Depot Website 


It sounds like you have a winner and the battery form factor is way better than the Craftsman 19.2 volt batteries I use (because I already had them). Let us know how they work over time.


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## John J (Dec 29, 2007)

I bought a second Ridgid 18 V 3 am hr Lithium Ion battery. In the instruction sheet it mentions the safty circuit in the battery. It tells how to reset it. If it does not reset the battery needs charging. They should get a good work out at Marty's I will let you know how I make out.


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## Greg Elmassian (Jan 3, 2008)

JJ, I was in home depot yesterday, went to the Rigid display... there was a sign there that tools and batteries CAN have a "Lifetime Service Agreement", but you HAVE to register with them... I think you can register online, but look for those exact words, and register, otherwise all you have is the "normal" warranty... 

Regards, Greg


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## barnmichael (Jan 2, 2008)

Posted By John J on 21 Sep 2009 12:34 PM 
I bought a second Ridgid 18 V 3 am hr Lithium Ion battery. In the instruction sheet it mentions the safty circuit in the battery. It tells how to reset it. If it does not reset the battery needs charging. They should get a good work out at Marty's I will let you know how I make out. 


So it looks like these Rigid batteries should do the job. What is the best way to connect to them without damaging their ability to go into the charger? Anyone know of a good readily available connector for the blades? A regular tab connector won't fit without cutting up the case.


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## Greg Elmassian (Jan 3, 2008)

A picture would be useful to those of use who do not own the batteries. 

Normally, you can use a female blade type connector, but can only speculate here. 

Regards, Greg


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## RIrail (May 5, 2008)

Unfortunately the RIDGID batteries (clam shell package) which are not sold in a tool kit i.e. drill, saw etc. are not covered under the Limited Lifetime Service Agreement and can not be registered as such on their web site. They come with only the standard 3 year warranty. Ask me how I know this. 
Hope your still happy. 

Steve


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## Greg Elmassian (Jan 3, 2008)

Dang, looks like you have to at least buy a drill... 

Greg


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## John J (Dec 29, 2007)

Well I got about 2 to 3 hours out of the batteries They worked quite well. Then the safty kicked in. Stoped the train dead. Of course it did it on a curve. Several cars plamented over the enbankmen. Holly Senek took some Pictures ane will be posting them.


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