I ran across this R/C aircraft site with a tremendous amount of information that everyone should read. http://tinyurl.com/zptzd
This is one of the things I’ve been watching. I’ve been toying with the idea of converting one or two locomotives to battery. But… The fire possibility has me concerned. I may have to clean track but I’ve never had a power pack explode. 
Warren
…then go with NiMh or better still NiCd.
NiCd is the oldest chemistry apart from Gel Cells which are real heavy and inconveniently shaped.
NiCd is by far the most reliable and they last the longer, in terms of the number of recharges, than NiMH. Twice as long is normal.
Whilst NiMh cells can store a lot of energy compared to NiCd, the popular and low cost AA NiMh cells should not be discharged at a greater rate than about 500 ma. Otherwise they will get too hot and their life is greatly reduced.
It is possible for NicD cells to develop the so called “memory effect” whereby they won’t take a charge. However, provided you don’t continually try and rapid charge partially depleted cells, you won’t have a problem. Especially if you use a modern conditioning charger like those made by Maha.
Gee, Tony, tell us what you REALLY think 
What do you think of NIMH batteries?
Tom,
I have no axe to grind either way with any battery chemistry.
I deal with all of them so I can report what my findings are from practical use over the last 20 years.
Gel cells are too big and heavy. They come in inconveniently sized packages and have only two commonly available voltages. 6 volts and 12 volts. Plus they drop voltage as they discharge.
NiCd’s win hands down. All are 1.2 volt cells with a convenient range of sizes. They can be ganged together in series to make up virtually any voltage. They last for years and are relatively inexpensive.
The only real downside to NiCd is that they are toxic to the environment if improperly disposed of.
Properly used, NiMh are acceptable. Same basic advantages as NiCd and store more energy. They are sensitive to charge and discharge characteristics. They last about half as long as NiCd.
I don’t consider them to be very good value for money.
Both Li-Ion and Li-Pol are yet to be proven in our circumstances. Maybe they are OK if you can remove them from the LS equipment and charge them in fire proof containers, but, for those of us who run locomotives with everything inside the loco, that is impractical.
If I have to keep beating the drum to make people understand that BS promotions is no substitute for the truth I will keep doing so.
Batteries included.
Also lithium rechargeables do not like deep discharge, and do not like a high rate of discharge, and they do not have as many charge-discharge cycles, more like 300-400 vs 1000 for a nicad.
The big advantage is they are much smaller and lighter, so for something that has a light load and will run 6 hours and size is important, like a cell phone, they are great.
Regards, Greg
Gentlemen, I didn’t post the above link to start a war, but there seemed to be a lot of interest awhile back on the lithium battery fires, now how in the world did this turn into a Nicad vs NiMh war in 3 posts?
No war, someone said they were considering lithiums, but were worried about fires, Tony says use nicads or nimh, but he prefers nicads.
Did you want us to talk about lithium fires?
Regards, Greg
No war John.
I just post em as I see em.
Greg has given a very useful precis of how Li-Ion & Li-Pol chemistry is probably best used for our purposes.
Light loads for long run times.
They can of course be ganged together in parallel to increase capacity. Something that is a No No with both NiCd and NiMh unless each pack is diode protected.
Some years ago I tested Israeli made rechargeable Lithium-Metal AA 3.6.volt cells.
These worked OK but, in terms of how many recharges I could get, they didn’t last very long at all. At all.
Like sound systems, I will only recommend them for use with RCS and EVO products when I am happy with the way they work.
Now see, you ask so you hear from the guys with the experience. Sounds like it’s the old familiar Ni-Cad for me.
Just to make my position clear, I actually think that the larger locos have so much current draw, and enough room that nicads would be my choice.
If I ran battery operated, I’d have lithiums in my smaller locos, mostly because of size constraints. Being smaller locos, they would most likely have lesser current requirements.
I also had some lithium metal AA cells, from Molicell. They are the only batteries I have ever set on fire. I purposefully overcharged one that had diminished capacity. It went off like a roman candle, burned a hole right through the positive terminal, about a 2 inch flame.
I still have several of them, sort of a museum, and possible future demonstration.
Regards, Greg
Greg, or Tony, or anyone else who might know…
Can a NiCd battery that has been badly treated be brought back to some useful life? I have some batteries for a camcorder that have developed a memory from being “put away wet,” put back on the shelf in the camera with more than half a charge in them and forgotten for months.
Is it possible to bring them back? Even a little bit? Replacements are beastly expensive. Probably cheaper to buy new technology than to try to hang on to a still good but 10 year old camcorder.
SteveF
Steve.
It may be possible to rejuvinate a NiCd pack that has developed a memory.
The following is offered without any guarantees and certainly with a warning that it could be dangerous so if you do it, do it in a sheltered place.
What I usually do is crank up my LGB starter set transformer/controller to full output, about 25 volts no load, Check the output polarity and put the positive wire to positive on the battery and the negative wire to negative on the battery.
Quite often, but not always, this will shock the battery back into action.
After a couple of minutes the overload on the LGB pack will trip.
Discharge the pack and repeat the process a couple of times.
Then try an overnight trickle charge.
Unless an individual cell has died you may extend the life quite a bit.
I have done the above with AA NiMh batteries in a 2 stick transmitter I had accidentally inserted backwards causing a couple of cells to reverse polarity when being charged. They did recover and I am still using them.
You can also get some large electolytic caps, and charge them up and discharge them through the batteries, plus to plus. The internal shorts that are causing your “memory” effect will have a lower resistance than the rest of the electrolyte, so this may vaporize the shorts. More effective than just just a power supply, and actually a bit safer, since the caps discharge right away, very little heating effect.
But, your batteries have been damaged as soon as they show memory, you might recover 80% of the original capacity, but they will never be as good as new.
I use about 500,000 mfd at 35 to 50 volts depending on the battery in question.
This only works on nicads, and a little on nimih, do not use on gell cells or lithium.
Regards, Greg
OK - Since this thread has sidetracked into a Ni Cad discussion… I have a question for Tony or anyone else who feels like answering.
Along with the statement that you and several others prefer Ni Cad technology over NiMh is usually included a mention of a conditioning charger. I’ve looked around the various battery websites and there appears to be a lot of hype being posted about chargers making it difficult to sort out the facts.
Would you be willing to state the brand and model of one or more conditioning charger that you would recommend? Ideally it would be capable of multiple cell sizes and various numbers of cells. I have in mind using a pair of 7.2V R/C packs in series for 14.4V in a trail car since I already have a few and they would serve multiple applications.
The 7.2 Ni Cad charger I have now is a specifically for 7.2V packs, it’s a Hobbyco 15 minute quick charger that also has a discharge function. It’s probably close to 20 years old and still works well, but I’m sure it’s not great for the packs.
Thanks -
JR
Hi Jon.
I can only pass on a recommendation for the type of charger I use here in Australia.
It is a peak detection charger made in China and imported by my battery supplier in Australia, Master Instruments.
It is limited to 12 x NiCd and NiMh cells. ie 14.4 volts nominal. It is not a full reconditioning charger.
When the new RCS website is up and running shortly I will be selling it here as a “SMART-CHG”.
Dave Goodson, Don Sweet and Jon Bliese are selling a conditioning charger made by Maha that can handle up to 14 cells. ie 16.8 volts. Contact either of them for
It will handle NiCd, NiMh and the Li-*** chemistry. I am testing them for Australia and will sell them here as a “V-SMART CHG”.
If you need to charge a greater number of cells than stated above, you will need to ask around as to what to use.
Tony:
I am currently using what was recommended / sold by RCS when I bought my systems over the last several years. That is a Radio Shack ‘wall wart’ coupled to an RCS proprietary charging board. Too late tonight to go look at the numbers, but it is a bare board with one green and one red LED to indicate charge / problem respectively. I thought this was the recommended charging unit.
Since you didn’t mention the above charging ‘system’ in your post, do I have the wrong stuff? I have recently (within a year) had to replace the NiCads in both my Shay and my Centennial 2-6-0. Should I be using something else to help get better battery life?
Thanks & Happy RRing,
Jerry Bowers
Tony, is the Maha the 777 or 777+ ?
If so, pretty good chargers, I have one of each.
Regards, Greg
Jerry.
No need to worry provided you stick to the specified maximum trickle charge rate.
The BACH-* series of chargers I make are designed for trickle charging NiCd cells only.
They should not be used with NiMh chemistry.
I needed to source another charger for NiMh that had at the least a peak detection circuit. I now have two at different price points.
Greg.
The label says 777PLUS-ii
Tony:
Thanks for the info.
I currently only use NiCads and the RCS charger. The locomotives (B’mann Shay & Centennial 2-6-0) are both completely self-contained (no battery car). They both have totally adequate run times. No need to tamper with success.
I just got a TX24 hand piece from TOC. Really an improvement over the original ‘gel’ button one. I really like not having to use shift key along with the significantly better range & more positive control.
Happy RRing,
Jerry Bowers