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Jim,

PS 2 is 5 volt .

No, that's not accurate. PS2 boards are either 5 volt or 3 volt systems. However, 5 volt PS2 boards (which this engine has) use 8.4 volt rechargeable batteries.

Regardless, this battery is a poor choice as compared to others. It has a low 160 mAh rating as compared to a variety of batteries available on Amazon (600-800 mAh), and also is quite a bit more expensive.

Barry Broskowitz posted:

Jim,

PS 2 is 5 volt .

No, that's not accurate. PS2 boards are either 5 volt or 3 volt systems. However, 5 volt PS2 boards (which this engine has) use 8.4 volt rechargeable batteries.

Regardless, this battery is a poor choice as compared to others. It has a low 160 mAh rating as compared to a variety of batteries available on Amazon (600-800 mAh), and also is quite a bit more expensive.

Thanks for the reply Barry. I'll look on amazon for a battery. 

Matt,

I began using Li-Ion 8.4 volt rechargeable batteries in my 5 volt PS2 engines  about a year ago with no ill effects. I use a different standalone charger than I do for the NiMH's, however, the Li-Ion's charge fine using the MTH battery charger or standing on a powered track.

Regarding NiMH rechargeables, I've found that the EBL brand that John is using to be a very good product.

Last edited by Barry Broskowitz
Barry Broskowitz posted:

Matt,

I began using Li-Ion 8.4 volt rechargeable batteries in my 5 volt PS2 engines  about a year ago with no ill effects. I use a different standalone charger than I do for the NiMH's, however, the Li-Ion's charge fine using the MTH battery charger or standing on a powered track.

Regarding NiMH rechargeables, I've found that the EBL brand that John is using to be a very good product.

Sweet. You guys know your stuff a lot better than I do. Figured it would good to ask here. 

This is a general opinion question about the 5V MTH engines.

I have a few 5 volt favorites. Once I became aware of the issues with the 5V & the white batteries I changed the white battery in every engine, 6 or more. I charged them, added power to the track, then did the shut down power, sound test, Barry has suggested. So far so good.

Now for the question. Do I run the engine until it blows or does it make sense to do an upgrade before the inevitable? Is the fix less expensive in an engine that is still functioning?

Thanks,

Joe

I think everyone that doesn't run their inventory of loco's or engines should annually take the shell of and check the battery. Since the early proto 1 and 5 volt PS2 boards are the boards known to have more problems than the PS2 3 volt board and PS3 not having a battery. I  would be safe than sorry. Just make sure all the wires are out of the way when putting shell back on your item that you looked at. I read Mr GGG, Mr. gunrunner"john. and Mr. Barry's stuff regularly. I think these guys are the best. I think they are very knowledgeable and always willing to help out.   Joe

I keep some 5V PS/2 boards to fix my stuff when they go, and when I run out of those, I'll be putting in the PS32 replacements.  I also replace any suspect capacitors that I can reach on the 5V boards as one in particular seems to be prone to failing.

I'm in the "run it until it drops" camp, however I do agree that regular maintenance and battery replacements are a good idea.  I write the date on the battery when I put it in a 5V locomotive so I have an idea how old they are.

If one is using a bcr for the ps2 5 volt systems can we just forget about the battery issue altogether? then just run the engine till the board craps out. 

fyi also, dont always rely on the mth documentation when deciding to purchase a used ps2 engine. I always looked up the product number and down loaded the engines manual. it usually tells you in there whether its a 5volt or 3volt system. this is not 100% accurate as I just found out. I down loaded the manual for a ps2 mikado. it stated in the manual that it indeed had the 3volt ps2 battery. so I purchased the engine. when I got the engine in my hands and saw the round charging plug I new I was in for a shock. turns out it was ps2 5volt with the white battery.  now I have a new speaker and bcr on its way and I hope it works as seller claims it was. ☹ lesson learned again. thanks mth. nothing against ps2 5 volt engines I just try to avoid them and save me all the headaches later on down the road. I luckly got this engine cheap so its not a total bumer. 

There has been more than one report that the high current draw of the BCR at startup has caused the charging circuitry of the 5V PS/2 board to fail.  While it hasn't personally happened to me, enough has been said about the possibility that I'm a bit loath to recommend the BCR for 5V PS/2 installations.  I use the BCR in PS/1 locomotives, and a supercap clone for 3V PS/2 boards, but I stick to the NiMh battery for 5V PS/2 boards.

Barry Broskowitz posted:

Matt,

I began using Li-Ion 8.4 volt rechargeable batteries in my 5 volt PS2 engines  about a year ago with no ill effects. I use a different standalone charger than I do for the NiMH's, however, the Li-Ion's charge fine using the MTH battery charger or standing on a powered track.

Regarding NiMH rechargeables, I've found that the EBL brand that John is using to be a very good product.

Are these the ones you use?

https://www.amazon.com/EBL-Rec...ithium-ion%2C+2+Pack

I have been using these:

http://www.farnell.com/datashe...276235357.1544721675

I get them from where I work but after reading that they are not the best choice, I want to know if the Li-ion's will work and charge as the original MTHs' did.

Thanks!

gunrunnerjohn posted:

There has been more than one report that the high current draw of the BCR at startup has caused the charging circuitry of the 5V PS/2 board to fail.  While it hasn't personally happened to me, enough has been said about the possibility that I'm a bit loath to recommend the BCR for 5V PS/2 installations.  I use the BCR in PS/1 locomotives, and a supercap clone for 3V PS/2 boards, but I stick to the NiMh battery for 5V PS/2 boards.

Something that is tangential to this BCR causing the charge circuit to fail on startup has been on my mind for some time.  What is the rise time of Wall Warts and Bricks that people are using to power DCS and TMCC layouts ?  Or worse yet people who use a standard transformer "ME, ZWs"  that is permanently  set on 18V and switched on and off with a master switch. NOT ME,  I dial the operating voltage up and down each operating session and have high speed breakers as well as TVS diodes.  To this, consider the life cycle of any electronic device.  At what moment are all these devices most likely to fail when operated within design parameters ?   Power up ?  Certainly not the only point of failure but I'm fairly sure it leads the parade. When I power up I dial the ZWs up to 17V in somewhere between 3 and 5 seconds. In addition, I always pre-charge my home rolled BCRs before I install in the loco.  This would lead me to the question, what portion of the charge circuit failures occur when a full 18V is applied to the track on start-up as opposed to a more gradual power-up.    Could some of these failures be prevented by pre-charging the BCR or a more gradual power up ?     j

Last edited by JohnActon

Well, I doubt you'd want to pre-charge the BCR every time you run the locomotive, the charge leaks off in a few hours.

If you're really worried about the charging current being the issue, rigging up an inrush current limiting circuit would be the ticket.  I'm going to do something similar with my MTH 44-ton locomotive.  I want to add a supercap, but since it's the small PS/3 board, I'm a bit concerned that going from .5F to 2F might be too much for the charging circuit.  That being the case, I'm going to add an inrush circuit to limit the charging current at startup, but it will allow full current in the reverse direction so the supercap can supply the sound when the power is removed.

John,

Why are you purchasing the 280 mAh EBL battery over the 600 mAh also by EBL?

Based upon Barry's recommendation of a 600-800 mAh EBL battery; it seems to me that's closer to the MTH battery's milliamp rating.  It does cost more however.

I'm just thinking your choice may have been based on inrush charging current vs the extra initial battery cost.

Just wonderin'

Best, Dave

 

gunrunnerjohn posted:

Well, I doubt you'd want to pre-charge the BCR every time you run the locomotive, the charge leaks off in a few hours.

If you're really worried about the charging current being the issue, rigging up an inrush current limiting circuit would be the ticket.  I'm going to do something similar with my MTH 44-ton locomotive.  I want to add a supercap, but since it's the small PS/3 board, I'm a bit concerned that going from .5F to 2F might be too much for the charging circuit.  That being the case, I'm going to add an inrush circuit to limit the charging current at startup, but it will allow full current in the reverse direction so the supercap can supply the sound when the power is removed.

 I bet you have your soldering iron on a timer set to come on 10 minutes before your alarm clock. Turning track voltage up slowly has worked well over 10 years for me no blown PS2.5 boards yet.     j

RJR posted:

In answer to a question above, the rise time is exactly the same a when you ptess and release the reverse button on conventional

 

Who uses the reverse button ?  In fact with a couple diodes and a cup of clever you can turn them into a Bell button.   Besides my daddy taught me in the fifties the direction button was for ripping the ratchet  fingers off e-unit drums.                 j

Last edited by JohnActon

john thanks for the tip about the bcr. I will get a green mth battery to as they say be better safe than sorry. I just hope my ps2 5 volt board works after all this. I have not tryed the engine yet. I only had 2 old white mth batteries and I was not about to use them. they got thrown away. the battery in the engine was an old cheap nine volt some one had installed. I am crossing my fingers that this board is ok. if it is I will use it till it craps and then upgrade to ps3 in this engine. I have been going over this engine,cleaning, greasing and servicing the smoke unit before even attempting to put it into service. 

I have sat on the side of this because opinions are so strong on this issue.  But sometimes facts get skewed as opinions form.  Frankly I think much of this is border line insanity on the issue.

First I can say I see an awful lot of MTH trains for repairs.  I dive into them pretty deep when I started, and I have a pretty good memory and such, and keep good notes from when I started.  I dissected and reverse engineered the boards well before even MTH was providing details on how to fix things beyond what the ASC Service manual said, and in fact I provided feed back on the book to correct many errors in diagnosing 3V faults. Especially the Power Supply board.

First,  I have seen PS-1 and PS-2 5V come in with original MTH White Batteries that still hold sufficient enough charge to operate the engines in conventional.  I have also seen them dead as a door nail and not hurt the boards.

So lets add some facts as I see them, and folks with deeper Electronic backgrounds can fact check me if I have misstated something.

Boards up until PS-3 designed to work with Battery not BCR.

MTH 9V batteries are 180 mahr batteries.  But this is just the charge they can provide.  Has nothing to do with how fast or slow they charge.

The PS-1 and PS-2 5V boards are operated on 5VDC.  So a 9V battery is stepped down to provide backup power.  It is also isolated in how it does it with current limiting resistors and transistors for turning on an off.   So how is a bad battery  killing a board other than some how maybe damaging the charging circuit.

All these microprocessor have protection circuitry, even PS-1 to prevent damage to the chips in the event battery backup or even power supply power is not sufficient, or too much.  For PS-1 issues it typically is that the voltage is just low enough to still operate the chip, but not high enough that data can be stored correctly to memory when shutting down.  This typically leads to a software conflict/ID conflict especially on earlier boards.  Later boards had different software and far less subject to software issues that would not resolve from shutting down and waiting a few minutes before restarting.

PS-2 5V have there own set of problems and many of the circuits that are made up to make a complete board run very close to design limits.  It was the first of its kind and build from 90's tech, but pretty state of the art for toy market.  So you see all kinds of failures and frankly not necessarily related to the capacitor issue we like to debate also, but in my opinion not the battery either.  Some models really had a higher failure rate then others and it did not necessarily carry over to every train made that model year.  No one has really done a compete failure analysis.  So what are we doing?  We buy insurance.

PS-2 3V is a far more robust design with much improved component and design work.  It operates a processor on 3.3V, so that 2.4V battery has to step up voltage to make things work.  The source of the 3.3VDC gets power from a 5VDC PS that I have seen smoke with a short.  Fix the short and that PS still works fine.  The battery sources that 5V PS when track power is off.  Both have specific protection built in to protect the chip.  In the thousands of boards I have repaired I think I have replaced 1, yes 1 5V power Supply and just 2 3.3VDC PS.   The only way you kill the board is putting AC on the DC Circuit of the board.  But that only kills the DC Components and processor chips that run the logic.  AC on the DC circuit and those power supplies still put out correct voltage.  It is the audio amp, speed control, logic chips, processors that get damaged beyond repair.

So lets get to the BCR.  Charging circuit is basically 2 functions.  One is charge the battery or in this case BCR.  Other is cut backup power in and out when Track power goes away.  Independent circuits with some co-dependency.  You can get one or the other failure, or both.  For PS-2 3V, there is one other circuit.  The boost.  Control of the inductor charging that adds the extra 2.5VDC to the battery 2.5VDC to make 5VDC for the Power Supply.  If that fails, a battery won't work because the voltage is insufficient, but a BCR will work, because the BCR Charges to a 5VDC level.  So the boost is not necessary.  So that is why some of you have seen engines not work with Battery but does work with BCR.  If the charging element is bad, the BCR won't work because it can't charge, but a battery does because it has a charge.  Works until battery charge is gone.  Then you need to externally recharge battery.  If neither work, most likely the circuit that cuts in and out the backup power has failed.

Again, I see far less 5V charging failure in all these years.  Whether BCR or battery.  Was it designed for bcr?  No.  Do they work?  Yes.  Same with PS-1.

PS-2 3V has a very robust Power FET used to control battery.  Can it fail.  YEP.  How?  Normally crushing the battery leads to the chassis.  Or some other AC on the DC circuit I talk about that kills the logic chip that runs the charging and cutting in and out FETs.  All repairable because of the board design, unless traces have burned up.  Why I see more damaged charging circuit failures in 3V then 5V is how the system works and that FETs are used to limit current charge and charging of the inductor boost.  When the logic chip is damaged it can tell the fet to conduct fully and when that happens you start drawing higher amps at startup that starts to smoke that 5VDC power supply until the fet burns up and opens. 

There are far too many engines out there (PS-1 through PS-2 3V) running on BCR and Batteries of all sorts to think your engine failure was because of them.

Defective BCR that is shorted will be a problem.  That rare battery that some how fails and acts like a direct short, same thing. 

But you will damage your engine far more via derailments, maintenance the crushes wires on reassembly then from installing a battery or BCR.

Hey I even saw a PS-2 3V upgrade that the person used the a 9V battery on and the board and charging circuit was not damaged.

So stop worrying about this and just do what you want.  Lets debate the best grease and oil for lubrication. G

 

Dave Garman posted:

John,

Why are you purchasing the 280 mAh EBL battery over the 600 mAh also by EBL?

Based upon Barry's recommendation of a 600-800 mAh EBL battery; it seems to me that's closer to the MTH battery's milliamp rating.  It does cost more however.

I'm just thinking your choice may have been based on inrush charging current vs the extra initial battery cost.

Just wonderin'

Best, Dave

 

Simple Dave, the battery is called on to do very little, and 280MAH is more than sufficient for the job.  Why spend more if you don't need it?

GGG posted:

I have sat on the side of this because opinions are so strong on this issue.  But sometimes facts get skewed as opinions form.  Frankly I think much of this is border line insanity on the issue.--------------

------------------------------------------------------------------------------------------------------------------------------------So stop worrying about this and just do what you want.  Lets debate the best grease and oil for lubrication. G

Thank you, GGG.   I printed your retort out and put it in my DCS repair binder.    j

 

Last edited by JohnActon

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