Possible battery convert with some questions

[Madman]

I am on the verge of converting at least one locomotive to battery operation. I thought, before I spend a larger sum on more advanced battery systems, I would have a go at the simplest conversion I can think of. I plan to use Ni-Mh AA batteries in a trailing car, and poer one of my LGB locos via the lighting socket. Ebay has AA rechargable Ni-Mh batteries for $.99/ea with free shipping. My question is that I see 2500 mAH and 3000 mAH versions. My simple brain would say that the 3000 model is superior to the 2500 model. I am assuming these numbers refer to the life of the fully charged battery. Would that be considered a correct assumtion? Is there anything else about simple battery operation I need to know.

 

[MR SPOCK]

Your correct about the battery size , the larger number, the more capacity and ouput power, and also the heavier and more bulky the battery, I have never used the type your thinking of as I use sealed lead acid types from intruder alarms,

 

[MRail]

Yes, Madman, you are correct.

Nowadays there are many power ratings available, all in the same size AA casing.
Generally, the more cells you wire into a battery, the higher the voltage, and the faster the loco will run.
The higher the mA/H rating, the longer the loco will run, so the higher the better.

You then need to organise a charger to match the overall voltage/current rating.

There are plenty of experienced experts on this forum who will be able to advise.

 

[Westcott]

I would suggest buying ready-made battery packs.
They are available in various voltages, so one big pack, or 2 or 3 in series, will give you the voltage you want.
Using packs saves having to wire up individual cells, and is the same price.

 

[dragon]

Don't forget to fit an in-line fuse.

 

[Tony Walsham]

AA batteries in a trail are good first up option.
However, unlike Sub C cells which can give a lot of power for a short time,AA batteries are designed for use with small appliances such as digital cameras and will give a smaller current for a long time.
If you try and draw much more than 1 amp you will shorten their life span. In terms of the number of re-charges you can obtain. Likewise, do not try and ram charge them at a high current. That will kill them just as quickly.

 

[Del Tapparo]

Dan - I have no experience using AA rechargeable batteries in trains ( I always go for larger cells), but I think the 2500 vs 3000 is most likely the same battery. Just a bit of "spec-manship" trying to make them sound better. In practice, I doubt you will ever notice a difference. In theory, of course, 3000mah is 20% more capacity.

Tony Walsham may chime in here (or maybe it was Kevin Strong?) .... I believe he has stated that the AA's have a limited current demand (instantaneous), i.e. they may not be able to deliver enough current on demand to satisfy a current hungry motor.

In any case, give it a go. It won't cost you much to give it a try, and I know many others have used AA's in battery holders in the past.

 

[Tony Walsham]

Hi Del.
I have quite a bit of experience with AA size cells here as they, and SubC sizes, are the only really affordable NiMh or NiCd batteries readily available in Australia.
AA's can definitely deliver a burst of current, at the cost of reducing the life span of the cells in terms of the number of recharges they can handle.
Keep the current drain and charge current at less than 1 amp, and they will last just fine.

 

[Madman]

I was able to do some experimenting today. I took one of my Stainz locos and separated the track power from the motor power. This is easily accomplished by using the two outer pins on top of the motor block for battery operation. This leaves the lights and smoke still powered by the track. My rough experiment was connecting a nine volt battery to the lighting socket on the rear of the loco, that I made myself, and running those two wires directly to the two outer pins mentioned above. This way I was able to keep the track power high enough to actully see smoke and the headlights now actually do something.

 

[Tony Walsham]

Until the track gets dirty.

 

[Madman]

Doomsayer:crying:

 

[Tony Walsham]

If you are going to bother cleaning the track just to get lights to work properly, you would be better off, and waste less time to boot, to wire the loco so that the lights run off the battery anyway.

 

[gregh]

I have 16 locos powered by AA size NiMH cells of 2000-2400 mAh rating. Some of them are 10 years old and some are the 99c types, which seem OK to me after only a years experience. ( None of my locos have smoke as the current load is just tooooo great for battery operation.)

I have connected between 4 and 11 of these cells in series to make up the required maximum voltage I need for a realistic speed for each loco. I solder all my cells together in series, but if you?re not comfortable soldering, you could use clip-in battery holders. You can get them in 4, 6, 8 cell configurations.

The mAh rating of batteries is given at a 10-hour current draw. That means a 2200 mAh battery will provide 220 mA for 10 hours (220 mA x 10 hours = 2200 mAh). If you take more than 220 mA out, the capacity reduces ?a bit?. And above about 5 times the 10-hour rating, you start to really limit how much charge you can get out of the battery. I?ve had only one set of AA batteries start to fail because I was taking 2 amps load.
All the rest of my locos taking usually less than 1 amp max are fine with the 2200 mAh AA?s. As long as you keep below the amp or so, the mAh capacity just tells you how long the loco will run for. At a constant 1amp, you should get 2 hours continuous running from 2200 mAh cells.

As others have said, it?s important to slow charge ( 12 hours at 220 mA).

The big problem with NiMH is the self discharge. I?ve seen figures that they lose 10% of their charge per week and my experience is that they need to be charged at least once a month. It means you need to think ahead when you are going to use the loco and charge it the day before, for max run time. Long shelf life (LS) types are now available but I haven?t tried them.

 

[Madman]

If you are going to bother cleaning the track just to get lights to work properly, you would be better off, and waste less time to boot, to wire the loco so that the lights run off the battery anyway.

I also want to run the smoke generators, which take too much of a draw on the batteries. With track power, even LGB 18 volt generators will put out smoke realistically. And for the locos that I will still run on track power, the tracks need to be clean. The main reason I want some battery powered locos, is so that my grandson and I can have some operating fun.

 

[Tony Walsham]

Eventually it will become evident to most Large Scalers track power is a waste of time, effort and most importantly money. Battery power solves all the problems. I hear this lack of run time foible all the time.
For anyone planning on having the traction batteries in the loco and they are concerned about run time being shortened too much by operating smoke units and lights etc. There is a very easy way to wire up extra batteries in a trail car that can be plugged into the loco to extend the run times considerably.
Or, if the batteries are in the trail car anyway simply double them up in two packs selectable with a switch (or diodes).
By all means have your layout set up for track power for guest locos, but I can assure you hybrid arrangements are not very reliable.

 

[MRail]

The main reason I want some battery powered locos, is so that my grandson and I can have some operating fun.

This rather gives the impression that using track power is not conducive to having fun with one's railway.
Erm... just going offline for a while.....

 

[gregh]

Eventually it will become evident to most Large Scalers track power is a waste of time, effort and most importantly money. Battery power solves all the problems. I hear this lack of run time foible all the time.
For anyone planning on having the traction batteries in the loco and they are concerned about run time being shortened too much by operating smoke units and lights etc. There is a very easy way to wire up extra batteries in a trail car that can be plugged into the loco to extend the run times considerably.
Or, if the batteries are in the trail car anyway simply double them up in two packs selectable with a switch (or diodes).
By all means have your layout set up for track power for guest locos, but I can assure you hybrid arrangements are not very reliable.

Spot on Tony. Couldn't have said it better.
Once you start with hybrid track & battery power, You'll find you forget to clean the track and wheels and track power gets less and less reliable.

 

[Bram]

I agree with Greg and Tony, battery power/RC is the way to go

 

[Tony Walsham]

I have heard from Dan and I understand why he is not R/C oriented.
Nevertheless, he is definitely interested in automatic battery operation and will try his hybrid method as well. As he should.

 

[Madman]

I didn't mean to imply that track power isn't fun. What I was saying is That my grandson and I can take control of the trains in our garden railway, as opposed to letting them run automatically by themselves, as they do now. In other words we can do some switching and so forth.


I still want to keep track power so that when I do just want to turn on a single switch, and sit back with a glass of whatever happens to be my beverage of choice at the moment, and watch them run and control their own operations. I have built a railway with automatic, self running, self station stops, station anouncements, and various other effects over the past twenty years. All based in track power and analog operation with great results. I tried Aristo's radio control and even LGB's without much success. Now I want to try again, however with the newer technology available, such as the stuff from Tony or Del.