Battery Power

[calenelson]

I run my annie with NiCads for about 3 or 4 hours and I'm ready to quit and go in...my HLW Mack has run for over 10 hours on 9.6 NiMH over the course of a few days w/o charge...simple....When finished, take the tender into the garage and plug into MAHA charger...go to bed, get up next day and run trains!

Engines could also be powered from trail cars if needed...no need to charge on track...seems like a wasted effort and funds/time that could be spent elsewher....

 

Q10

cale 

[grandpopswalt]

Dave,

How about this. Rig a restraining board across the charging track which would be deployed as the loco comes slowly into the siding. After the loco is stopped by the restraint, increase the voltage until the wheels start to slip. This will automatically clean the wheels and the track thus assuring good contact. After a few seconds stop the wheels and allow the batteries to charge. When it's time to leave, retract the restaint and off you go. 

Waddayathink? You know, when you're retired you just have too much time to come up with off-the-wall ideas like this.

Walt 

[rrebell]

just noticed this thead and have always thought about a charging station idea. As far as batteries problem a cell phone battery setup works like what you want, my power goes down I can plug it in and it will charge till needed, it can charge and discharge as needed, even both at once.

[Greg Elmassian]

I'm a latecomer to this thread, but some very interesting stuff here.

I've often thought about a battery powered loco and recharging the batteries from the track.

It seems very attractive at first. Just power most of the rails, don't power the turnouts, and leave long dead sections where a reversing loop would be in a normal track powered layout.

But when you start looking closely, it is just not practical.

For example, like Dave said, the inrush current when the batteries want a charge would be a very heavy load on the components picking up track power. You would need a lot of heavy components to handle this. Rewiring and high current pickup stuff would be a real problem to fit and would cost a lot.

If you limited the inrush current so as not to destroy the stock pickup "parts" in a stock loco, then you would severely limit your ability to recharge the batteries. Combine this with less than perfect track cleanliness and you have a problem. If the track is perfectly clean all the time, then why run batteries?

All of the extra electronics required to put this in the loco will take up a lot of space, and gel cells are not small to begin with, so you again have some severe limitations in what locos can run, or you always have trailing battery cars.

But, I will give you another severe limitation or cost factor: I am one of the people that do charge some batteries with the "constant, fixed voltage" method.

It CAN work. But there are 2 factors that will make it impractical for you. The difference of even a few hundredths of a volt will greatly change the charge. I have found in over 10 years of doing this exact method that I need to set the voltage exactly for EACH pack, and regulate to about 1 or 2 hundredths of a volt. This means each regulator needs to be set for EACH pack. Further, you cannot regulate to this accuracy with anything as inexpensive as your cheap 3 terminal regulator. I use precision laboratory power supplies, and read out the current and voltage to hundredths.

Also, as the battery ages, the terminal voltage to reach the appropriate charge changes. Normally it goes down. Thus without adjustment, you will soon be overcharging batteries.

I have battery packs with the proper charge voltage marked on them on a sticker, to .01 volt. I also monitor the terminal charge current, and as the battery ages, I update the sticker with the new terminal voltage. It does work, but I really believe it is not at all practical, since you have no way to monitor and update this unless you put voltage and current meters in every loco, AND observe terminal charge conditions.

As Dave is fond of saying, been there, done that.

And I only have 2 degrees and no phd, but, theory is a starting point, experience is the confirmation.

Regard, Greg