PS-2 Niagara 20-3047 BCR or green Battery???

It's just my opinion, but I think charging up a half dead battery would put more stress on the electronics than a BCR that charges up fully in a minute or two.

Put a new green battery in it...cost me $290.00 to repair the same engine because I screwed around with a weak battery.

Joe Allen posted:

It's just my opinion, but I think charging up a half dead battery would put more stress on the electronics than a BCR that charges up fully in a minute or two.

Actually, that's not true.  A discharged battery doesn't present the super low impedance that a flat discharged supercap does.  A supercap will consume vast current if you let it when it's first connected with no charge.  The much higher internal resistance of a discharged battery will not draw nearly as much current.

Now I'm confused.  If I have an engine with a weak green battery, (or a battery that I don't know the condition of), am I better off charging it or replacing it, or changing to a BCR?

Very simple, put a BCR in it and end your battery troubles.

gunrunnerjohn posted:

Joe Allen posted:

It's just my opinion, but I think charging up a half dead battery would put more stress on the electronics than a BCR that charges up fully in a minute or two.

Actually, that's not true.  A discharged battery doesn't present the super low impedance that a flat discharged supercap does.  A supercap will consume vast current if you let it when it's first connected with no charge.  The much higher internal resistance of a discharged battery will not draw nearly as much current.

While this may be true, you are only charging the BCR on startup and not running the engine. With a dead battery, you are still trying to charge the battery and run an engine's motors and smoke unit if eqiupped causing more stress on the electronics. Of course the is JMO and I can't prove it.

Thanks, guys.  I knew I would get good advice.  From my perspective make sure the green battery is fully charged before attempting to run the engine.  Replace it with a BCR as soon as possible.  You're just tempting fate trying to run an engine from this time period with an out-of-date battery.

I don't routinely put BCR units in the PS/2 5V board locomotives, but it's not my locomotive, so you're free to ignore my advice.   What could I possibly know, I'm just an electrical engineer, designed multiple circuits with supercaps, gone to the MTH training, and have repaired many MTH locomotives.

Thanks for the reply.  You're advice is the one I value above others.  A few years ago I bought a used MTH PRR Atlantic from you.  A good value and a good runner.

I prefer to install BCRs in my MTH engines and run conventionally. I try to minimize the initial charging current into the capacitor by advancing the throttle lever very slowly, taking about 10 seconds to get to 10 volts while the BCR is getting charged.

MELGAR

First,  if the 5V engine has a charge port, the idea is to use the MTH charger and charge the battery before running it if it sat that long.

Second, I do not believe the battery kills the board either.  I have the same pedigree as John other than EE, designed boards, but I do stay at Holiday inns and also have a lot of experience repairing these engine including for MTH.

I am still pulling original batteries out of PS-1 and PS-2 engines that are working.  I have seen plenty of BCR in 5V boards.

Plus there have been plenty of 5V engine with new batteries in them that ran fine, and the next day they started it up and it smoked and shorted.  There is no proof that batteries cause this failure.  Worst case would be the charge fet is damaged, and that just does not kill the board.  FAR MORE Current is drawn by the Audio amp especially at startup to make the initial sounds.  So much current that some 5V sound files had code to limit audio output at startup to prevent the 5V power supply from shutting down.

I am sorry it just ain't true, but believe what you want.  Battery or BCR makes no difference.  G

Thanks for all the great info on this thread. It is an interesting discussion. 

The Niagara does not have a charging port . The first run Dreyfuss that I also have does not have a charging port either. That one has  a green battery in it but it has not run in about a year as well.  

I have purchased MTH batteries  with part number 50-1008, The same part number cards have had the Green NIMH battery and a white NICD battery with a case more like the Green battery and different from the early white batteries used in the PS-1 days.  The two batteries have different part numbers, Green being BG-4000005 and white BG 4000001. The current MTH catalog shows a green battery so thinking that  is the latest from MTH. 

If I were going to run that Dreyfuss with the green battery, I would let it sit on a track with about 14 volts for about an hour before attempting to start ii in DCS. I would have done the same with the Niagara last night except I was curious to see if it had a more recent battery than it might have come with when new. I had bought the engine used and was told that it had a replacement battery which is what I found . What surprised me was that the newer style NiCd white battery had only about 1 volt in it. Perhaps it might have charged to normal voltage letting it sit on the track for an hour . I used the BCR as an alternate so I could run it last night. . Thinking I might go back to a battery when I have some charged batterries ready to go. 

The last thought I have on batterries is that of the two types I have seen as cat no. 50-1008, the Green NIMH might be the way to go. 

Thanks all for your thoughts, advice and help. It is most appreciated. 

In the 9V battery world, the NiCad has become some what obsolete because of the Cadium concern.  Batteries ordered from MTH come in Green and are the NiMH variety.  I still pull MTH white and even silver type batteries out of running and non running engines.  Some even have enough of a surface charge to change direction in conventional.  But they are way past their useful life.  G

Given the short probable life of a 5-volt board, is it worth the expense of a BCR or the effort of assembling a supercap?

Personally, I just put a new NiMh battery in them.