Rechargeable Battery's

Billy, the answer to your question is a bit complicated.  No, you don't have to use MTH brand.  But:  In fact, a rechargeable battery can never be 9 volts, because N iCad and NiMH cells are 1.2 volts, not 1.5 as is an alkaline battery, and therefore no combination of NiCad or NiMH cells will yield precisely 9 volts.  MTH's "9-volt" battery is actually 8.4 volts, being made up of 7 cells.  Most so-called rechargeable "9-volt" batteries are actually 7.2 volts, having the same number of cells as an alkaline.  The 7.2-volt "9-volt" batteries are not suitable. 

280 mah is the battery's capacity. MTH's 8.4 volt battery is actually 120 mah.  Yous is more than adequate. The MTH 3-volt battery is 700 or 800 mah capacity---I've seen both.  I believe Sam is thinking of these.

A BCR is not a battery.  It is a supercapacitor.  The seller combines a supercapacitor with some zener diodes (to provide even charging) in the model it markets for 9-volt systems.  I don't know whether its version for the 3-volt systems has zener diodes.

On some of my 3-volt locos that get used less often, I have replaced the batteries with 2.5 farad supercapacitors from Digikey, without using zener diodes.

I would add that I have had no problems with MTH batteries, and get 9-10 years on their 2.4 volt batteries.  I would also add that 2/3AA size 2.4 volt batteries, 800 mah, are available from China for about $2 each, to which you'll have to add plugs, which can be cut from a shot MTH battery.

Thanks for the info.....

LI-Ion has a very different charging profile than do the Ni-Cad batteries that the early MTH electronics was designed for.  I'd stick to Ni-Cad or Ni-Mh batteries for this use, they are proven to function in this environment.

I believe the EBL battery you specify is a 7.2V battery, that also makes it unsuitable for the MTH locomotives.

Ah, OK. So the MTH 9V s only 120 mah? So most likely you will have no problem using the 280mah, 9V after market ones.

The biggest problem with the MTH 5/3V batteries is that many trains sit idle for months at a time or even weeks. These batteries have a "self discharge" curve and all of them will discharge to almost zero volts in a few weeks. Staying fully discharged kills their life expectancy. Ideally you want them full charged when not in use but that can be very difficult if you have 30-50 engines. So what happens many batteries sit uncharged for a long time and they go into reverse polarity OR one cell just opens up into high impedance and prevent the whole battery from being charged again, hence replacement is a must!

Self discharge rate...

Sam,

So most likely you will have no problem using the 280mah, 9V after market ones.

Actually, that's incorrect.

Although the 280 mAh rating is just fine, the "EBL, 6F22, 280 mAh 9V rechargeable battery" is a lithium Ion (LI-Ion) battery and will not charge properly in an MTH PS2 engine.

I did not relaize the EBL battery was Lithium ion.  My colleagues are correct.  Do not use.  It could be hazardous.

all of them will discharge to almost zero volts in a few weeks

I disagree as to duration .  A few months would be more like it, especially NiCads, which will last many months.

Thank you all again will be ordering the MTH battery, I am glad I asked and did not use the battery yet.

Robert,

A few months would be more like it, especially NiCads, which will last many months.

I agree. MTH once confirmed for me that their original "white" NiCad loses about 20% of its charge per month.

I just went through a round of battery charging/replacing and only (7), 8.4 volt batteries needed to be replaced. I purchased a bunch from TNR (the battery store down the road from where I live) and the new ones are 250 mAh NiMH's. They were reasonably priced at less than $6 each in lots of 10 batteries.

Seems you've already decided on the MTH product, but I'll add for others:

I recommend looking for batteries that are marked "low self-discharge" or "Pre-charged".  these will hold a at least 70% charge after sitting for up to a year on the shelf.  Duracell's "9V" ( really 8.4V) runs about $10-12 in any retail store with a large selection of batteries.  Rayovac makes a quality product for a few dollars less.  You can also find off brand products for $4-6 all over the internet, though I have no experience with off brand 9v batteries.  In the AA size i've found that only Duracell and Rayovac are worth buying.  Energizer and all off brands have had a high rate of failure for me.  

John, I didn't realize Duracell has an 8.4 volt rechargeable.  I've only seen their alkaline.  Their web site doesn't show any "9-volt" rechargeable, only AA & AAA.

When I got DCS, in 2002, I soon realized alkalines in the remote would bankrupt me and bought 2 sets of Rayovac 15 minute recharge NiMHs.  I am still using them, and there are no discernible reductions in duration between recharges.  Could be that they are not onon the charger too often that has prolonged their lives.

In my experience, Duracell's line of 'Pre-charged' rechargables is the best battery out there. Rayovac is a close second.  In the company I work with we we use about 200 AA batteries which have tend to be charged 1 or 2 times per week for 4 months, then are set on a shelf for the other 8 months, and another maybe 50 AA's that are used year round with charges once a week.  The Duracell and Rayovac have shown no problems with being stored unused, where as other brands, especially Energizer, are 50/50 on if they will hold a full charge when brought back into service the next year.  The oldest set I have documentation on ( I write the date I start using them with sharpie on the batteries) was bought in march of 2009, and still performs like new.  Some things that help is using a slow, low current charger, though i've never had problems with duracell on their 15 minute fast chargers.  Other brands REALLY do not like the fast chargers in my experience.  

The 9v are a little less common in stores than the AA types, but they are out there.  They are also readily available on the internet.  

NiMH is nickel–metal hydride it is similar, but not the same as NiCd (Nicke-cadmium) The original MTH white batteries were NiCd, but I believe the newer 'green' ones are NiMH.  The NiCd's main downside is the awful charging memory.  They don't work well if you do not fully charge, then fully discharge them each cycle.  NiMH are much more forgiving on this.  

http://en.wikipedia.org/wiki/N...etal_hydride_battery

http://en.wikipedia.org/wiki/N...dash;cadmium_battery

If you have ANY engines still with the white NiCd batteries, the popular consensus around here is to replace them immediately, to avoid damaging electronics, especially in PS1 locos.

I believe there have been threads reporting success with the Harbor Freight 9V-style NiMH battery which is 8.4V 200mA-Hr and now on-sale for $7.99:

http://www.harborfreight.com/h...t-battery-97865.html

So with those Harbor Freight 20% coupons you find everywhere, it's less than $7 which seems pretty good (vs. 11.95 MSRP for MTH 8.4V 120mA-Hr NiCd).

The green batteries are indeed NiMh.

LOL.  OK, I'm imagining how easy it is for YOU to contact MTH to let them know

The memory effect is overstated for our use.  The real down side to NiCad is the Cadium.  From an environmental perspective.    G

Too much cut an paste, I don't think anyone working there has ever had to worry about critical documents.    G

Since I have some of them in the parts box and they clearly say NiMh, I think I'll go with the actual battery rather than outdated specs.

I have mth 9 volt  in both NiCad and NiMH.

In the Harbor Freight link, I saw no indication of actual voltage.  Did I miss something?

I can't tell what you're pointing to Stan, can you be more specific?

No good deed goes unpunished...

Very funny.

NOW I SEE IT!

This is a test...

You guys need to get real jobs.  I am retired and I don't have time to do this.  G

GGG, just because you have retired, that doesn't mean you have to halt the levity that made pre-retirement bearable.  I am sure you know this and are just doing some leg pulling.

If you don't have a sense of humor, is life worth living?

John,

If you don't have a sense of humor, is life worth living?

I don't know. Please tell us, based upon your first-hand experience.

Now we have to ask to forum master to move this thread to the Philosophy forum.

I think a lot of threads go there, as that's that secret hidden section.

We spent hundreds of dollars on these engines,  to me.............  $7-$15 for the rechargeable battery that has a definite life span vs.  BCR for double the battery price and you can forget it had a battery in it.

How much is Peace of mind worth?  (Uh,  oh,   is this now a philosophical discussion?)

I'm actually going to take the opposing view here.  With NiMH batteries where they are these days, I can't see replacing a large fleet of locomotive batteries with BCR's. For the most part I agree that the BCR is better technology... as long as quality capacitors are used that won't break down after several years.  If I had one or two, or even five engines I'd probably recommend the BCR, but if you have several dozen, as does the guy in the other post running on BCR's, I can't see spending several hundred more dollars for what amounts to the same functionality.  Yes, in maybe 5-8 years they might need to be replaced, but then, I'm unsure what the functioning life of the super caps is.  I'd like to think they are as good as some of the WWII surplus 1/10 Farid, 32oz can sized, caps I have, that still work just fine, but I sort of doubt the ones in a BCR will really last forever.  As far as the batteries, as I mentioned above, I have sets over 5 years old with at least 250 full drain charges on them that work as good as new.  Check back in 3-5 years and I'll let you know how the test set is holding out.  

To sum up, if you go with MTH list it will take about what? 15+ years before a BCR pays for it's self, and using the $5 batteries found all around the net, it's more like 30-40 years...

BCR's are really neat products, just not at all cost effective in a large number of engines at this time... On the other hand the actual parts are less every day, so so maybe soon they will be cheaper than a battery.  

One should also do some reading on the life of SuperCAPs, they're not necessarily a lifetime replacement.

The 2.5F 5V one frequently used for the 3V boards has an MTBF of 1000 Hrs @ 85°C.  That's actually better than many others that go for 1000 Hrs @ 65°C.

I tend to agree with JGL's analysis, but I have recently installed a few supercaps that GRJ mentions.  Ask me in about 10 years how they've held up.   One reason for the price of BCRs ("BCR" is a brand name) is that they include zener diodes to enhance proper charging-up of the capacitors in the 8.4 volt unit.  Given the life expectancy of the 5-volt boards, I can't see replacing a battery with anything other than an 8.4 volt battery.

I also agree with Nativefl about using BCRs/supercaps in locos that sit for many months or years.  As my roster grows, some locos get used less.

To date, I have heard no complaints about the performance of any of the BCRs