Large Scale Central

Lithium battery warning

Electronics Power and Sound
#21

Given that Li-xxx batteries require proper charge rates and constant monitoring, I will be interested to read how the newly announced AristoCraft track pick up battery power car with constant on board charging of battery packs will handle the variations in voltages of the layouts AC will be selling to.

The idea will work provided the user can provide exactly the voltage required on the track.
Either that, or AC must be going to have some sophisticated voltage dropping circuitry in the trail car to supply the correct fixed voltage.

Just another idea that has been “borrowed” by AC.
I wonder if it will require as much after market modification as the PWM converter recently released?

#22
TonyWalsham said:
Jon, If the Porter is of the saddle tank variety here is how I did my conversion.

http://www.mylargescale.com/Community/ForumArchives/tabid/100/Default.aspx?TOPIC_ID=19441

The hardest part was slicing the metal weight in half.
Gordon Watson kindly did it for me on a metal cutting band saw.


Mine is the side tank version, but thanks for the link - I’ll check it out.

#23

Tony, I am waiting with bated breath on how the AC unit works. It was announced:

“This is not new, but we are designing our own circuit to charge any battery pack automatically. Like others, this circuit will ever-green charge the battery from the track power and never deplete. This means that the loco can run 24/7/365 without manually replacing and recharging the battery.”

hahahahahaha

charge any pack… impossible

In order to charge a li-ion battery, you need a microprocessor based charger. Interrupting power to it will reset it. This cannot work properly.

You can set up a “trickle” charge circuit, with a voltage regulator putting out a fixed voltage, but then there are no smarts. This works, and can “Extend” your run time, but now you are using nicads, even nimih will not work well with this setup, and of course li-ion will not work.

I really want to see this…

Greg

#24

Hi Greg.

LI-Ion. Yup, interrupt the flow and it resets. Perhaps an on board battery to keep the IC alive would be an idea. :wink:

NiCd. Sure, a simple trickle charger would work. However, the values have to be set up accurately to cater for track voltage, battery voltage and charge current. You need a reasonable overhead to be able to do this. to charge a 14.4 volt battery at about 200 mah you will need at least 19 volts on the track. I know. I built one years ago.
So there can be no general system that a consumer could use. Not without complicated programming to cater for the above.

NiMh Same as NiCd, but, with the added complication of cutting off when fully charged. If you don’t do that, even on simple trickle charge, the life of the NiMh battery pack will be depleted.

You are not on your Pat here. I too await with interest to see how the wheel is attempted to be reinvented.
The mind boggles at the BS the redoubtable Mr Polk can get away with.

#25

Tony, not familiar with the phrase "you are not on your Pat:

On the trickle charger, you could put a regulator in the car, a simple series regulator, then the voltage would be known. You could set it to a reasonable voltage, but a poor way to do it, because a slight variation in voltage results in a wide swing in charge current.

If you put a current regulator in, the best you could do is a trickle charge, which (in my definition of a trickle charge) you would eventually overcharge the battery, but you have a slight hope of putting some charge into the battery.

The only safe way to allow the system to charge forever is to put in a current regulator to allow only a “float charge” which is the current that a nicad will tolerate forever, but this results in a VERY slow charge, so this would effectively be useless in extending battery run time.

So, I am awaiting a technological breakthrough. Maybe I have missed something in my almost 40 years of experience with rechargeable batteries, time will tell.

The only thing I can think of that would work and give any meaningful performance is a microprocessor controlled charger that has a constant power source so it cannot be reset, and an algorithm that would tolerate interruptions in the charging power source. I have never seen one made, but it could be done.

Regards, Greg

#26
Greg Elmassian said:
Tony, not familiar with the phrase "you are not on your Pat:

Regards, Greg


Cockney rhyming slang.
An abbreviation of: On your Pat Malone = alone. Therefore “you are not on your Pat” means you are not on your own.

Greg Elmassian said:
On the trickle charger, you could put a regulator in the car, a simple series regulator, then the voltage would be known. You could set it to a reasonable voltage, but a poor way to do it, because a slight variation in voltage results in a wide swing in charge current.

If you put a current regulator in, the best you could do is a trickle charge, which (in my definition of a trickle charge) you would eventually overcharge the battery, but you have a slight hope of putting some charge into the battery.

The only safe way to allow the system to charge forever is to put in a current regulator to allow only a “float charge” which is the current that a nicad will tolerate forever, but this results in a VERY slow charge, so this would effectively be useless in extending battery run time.

So, I am awaiting a technological breakthrough. Maybe I have missed something in my almost 40 years of experience with rechargeable batteries, time will tell.

The only thing I can think of that would work and give any meaningful performance is a microprocessor controlled charger that has a constant power source so it cannot be reset, and an algorithm that would tolerate interruptions in the charging power source. I have never seen one made, but it could be done.

Regards, Greg


I too would like to see something new invented that would be useful to Large Scalers.

Somehow I think form (as usual) will prevail over substance.

#27

little off topic here, in regards to Aussie slang:

I’m in the midst of the “Tomorrow” book series by John Marsden (AU), and luckily for me he included a glossary in each book that helps this ole’ Rebel understand what a few words mean!

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