Large Scale Central

Battery Powered Passenger Car LEDs

Electronics
#1

My latest project is a string of age appropriate passenger cars for my detailed Kalamazoo 4-4-0. When I started the project an embarrassingly long time ago, I was going to use track power and capacitors to avoid the dreaded blinkys. However, I am now impressed with the rapidly advancing small battery technology and am exploring batteries in each car. One that intrigues me is a Garberiel 3.7v 6000mah li-ion cell. The 6000mah seems too good to be true. Would this work in my application? Am I missing something?

Thanks,
David

#2

David,

A 3.7V, 6000mAh Lithium battery is certainly doable. That said 6000mAh battery is a lot of battery power for a single coach me thinks. Are you going to retain the incandescent OEM bulbs? LED’s typically draw about 20mA each while incandescent T1 bulbs atypical of our coaches run the gamut, maybe 70-170mA.

Make sure you employ a charger designed specifically for Lithium cells and the voltage and or battery size you have in hand!

Michael

#3

David Palmeter said:

One that intrigues me is a Garberiel 3.7v 6000mAh li-ion cell. The 6000mAh seems too good to be true.

They lie. Highest capacity Li-ion 18650 battery you can get is like 3400mAh. A quality 3400mAh battery should power LED’s for about a solid week.

#4

David Palmeter said:

My latest project is a string of age appropriate passenger cars for my detailed Kalamazoo 4-4-0. When I started the project an embarrassingly long time ago, I was going to use track power and capacitors to avoid the dreaded blinkys. However, I am now impressed with the rapidly advancing small battery technology and am exploring batteries in each car. One that intrigues me is a Garberiel 3.7v 6000mah li-ion cell. The 6000mah seems too good to be true. Would this work in my application? Am I missing something?

Thanks,
David

David - the cells that I use are rated at 3000 ma and I believe that claim - they also have a built in protection circuit that prevents overcharging and over discharging - If you don’t have such a circuit you can easily kill a LiIon cell.

Here is a link to where I purchased them

https://www.amazon.com/18650-Rechargeable-Lithium-Ion-Batteries/dp/B01CIN1XF2/ref=sr_1_fkmr0_1?s=electronics&ie=UTF8&qid=1523310403&sr=1-1-fkmr0&keywords=ecogear+fx+3000ma

dave

#5

Thanks to all for your comments. Yes, I will be using LEDs and want all the mAh I can get for the longest possible time between charges. Further research indicates ‘mAh’ scams up to 9900mAh of fantasy and/or dangerous power. So, some questions:

The cells that you mentioned, dave, were noted in Amazon comments to be a bit larger than some.

What charger do you use?

What cell holders do you use?

I am assuming that the 3.7v can be fed directly to the LEDs in parallel without resistors - true?

#6

David Palmeter said:

Thanks to all for your comments. Yes, I will be using LEDs and want all the mAh I can get for the longest possible time between charges.

I am assuming that the 3.7v can be fed directly to the LEDs in parallel without resistors - true?

David,

You cannot run the 3.7V cell unbridled… Off charge Lithium are generally in the 4.2V range…

FWIW: Running Lithium batteries down to voltage cut-out numbers is highly detrimental to the cells life cycle. Yes a bigger mAh battery will allow you longer run time between charge intervals. That said if it were me I’d run the batteries down know more than 60% if I expected them to last for years. You can charge Lithium battery technology as often as you like without issue, even if they are slightly discharged.

Michael

#7

David Palmeter said:

Thanks to all for your comments. Yes, I will be using LEDs and want all the mAh I can get for the longest possible time between charges. Further research indicates ‘mAh’ scams up to 9900mAh of fantasy and/or dangerous power. So, some questions:

The cells that you mentioned, dave, were noted in Amazon comments to be a bit larger than some.

What charger do you use?

What cell holders do you use?

I am assuming that the 3.7v can be fed directly to the LEDs in parallel without resistors - true?

David - I would use a current limiting resistor with the LEDs just to be safe. You could also use a CL2N3 to limit current - very cool device - see

http://www.trainelectronics.com/LED_Articles_2007/LED_104/index.htm

The spec sheet says they need 5 volts to operate - I have not tried them with a single 3.7 volt cell - I’ll give that a try and get back to you.

The cells are larger (longer, actually) as they have the protection circuit installed - I use magnets to hold the connections in place - I have also soldered wires directly to the cells - not something to try unless you are very fast and very careful as Lithium Ion cells don’t like heat.

And I frequently use a charger that holds on with magnets - very convenient - see

https://www.banggood.com/Folomov-A1-Multifunctional-Mini-Portable-Magnetic-Li-ion-Battery-Charger-p-1228676.html?rmmds=search&cur_warehouse=CN

dave

#8

David - we can cross the CL2N3 off of the list of options - the device was true to its data sheet - I just tried one and it didn’t start conducting till it was close to 5 volts -

A 15 ohm resistor worked well and allowed about 30 ma at 3.7 volts with a 5 warm white LED load - when I increased the voltage to 4.2 volts the current went up to 50 ma

I hope that helps

Have fun experimenting!

dave

#9

How is this for a coincidence? The latest email blast from Instructables has a feature on how to make magnetic connectors for 18650 cells

see

https://www.instructables.com/id/Magnetic-Connectors-for-Batteries/?utm_source=newsletter&utm_medium=email

dave

#10

David Bodnar said:

How is this for a coincidence? The latest email blast from Instructables has a feature on how to make magnetic connectors for 18650 cells

see

https://www.instructables.com/id/Magnetic-Connectors-for-Batteries/?utm_source=newsletter&utm_medium=email

dave

As well as battery connections, functiional cat-to-car connections?

#11

"How is this for a coincidence? The latest email blast from Instructables has a feature on how to make magnetic connectors for 18650 cells

see

https://www.instructables.com/id/Magnetic-Connectors-for-Batteries/?utm_source=newsletter&utm_medium=email "

That IS a coincidence, dave, I was just going to ask how you connect wires to a battery, I am not comfortable soldering to a Li-Ion battery. Also, I am going to build the whole lighting system into the roof and use magnets to attach the roof to the car body for easy access. Thanks to everyone for all your comments, I’ll post the results when I get the cars back together and get the light assembly built…

#12

Any suggestions where I might get these magnets from a reliable vendor at a reasonable price? I assume they are neodymium. The big auction site has questionable vendors listing them with strange descriptions. Thanks!

MagnetsRound

#13

I googled;

https://totalelement.com/?gclid=EAIaIQobChMI7p7flICp2wIVmMpkCh2rmQhBEAMYASAAEgKDGfD_BwE

They seem to have a wide variety.

I have a couple of tubes / safety caps, that are all warnings and no product info… so weird packaging seems a norm

#14

"John Caughey said:

I googled;

https://totalelement.com/?gclid=EAIaIQobChMI7p7flICp2wIVmMpkCh2rmQhBEAMYASAAEgKDGfD_BwE

They seem to have a wide variety.

I have a couple of tubes / safety caps, that are all warnings and no product info… so weird packaging seems a norm"

Thanks! It looks better than any source I could find; I’ll give them a try.

#15

I’ve had very good luck with KJ Magnetics. I’ve used them for lots of different projects and never been let down by the quality - first class all the way.

#16

"Bruce Chandler said:

I’ve had very good luck with KJ Magnetics. I’ve used them for lots of different projects and never been let down by the quality - first class all the way."

Thanks! KJ has no minimum order, Total Element mentioned above only sells in larger quantities but prices are lower. I’ll research both to get what I need.

#17

David Palmeter said:

"Bruce Chandler said:

I’ve had very good luck with KJ Magnetics. I’ve used them for lots of different projects and never been let down by the quality - first class all the way."

Thanks! KJ has no minimum order, Total Element mentioned above only sells in larger quantities but prices are lower. I’ll research both to get what I need.

Never knew that; probably a good thing as I would just order a few of many different sizes, just to try to figure out what might work. Of course, if there was a minimum, I probably would have ended up with a lot more magnets in my collection. The other cool thing about KJ is that they periodically send out emails about various magnetic projects. Very fun.

#18

Bruce Chandler said:

David Palmeter said:

"Bruce Chandler said:

I’ve had very good luck with KJ Magnetics. I’ve used them for lots of different projects and never been let down by the quality - first class all the way."

Thanks! KJ has no minimum order, Total Element mentioned above only sells in larger quantities but prices are lower. I’ll research both to get what I need.

Never knew that; probably a good thing as I would just order a few of many different sizes, just to try to figure out what might work. Of course, if there was a minimum, I probably would have ended up with a lot more magnets in my collection. The other cool thing about KJ is that they periodically send out emails about various magnetic projects. Very fun.

Thanks, just signed up for their mailings…

I like the informative site, easy to see what you are going to get.

#19

Maybe not suited for the cars described in this thread, but I think the following info. may be useful:

A 9 volt type battery, though relatively large can be housed in a case (with an on-off switch) maybe located on the under side of a car. The battery can then be removed for charging in a dedicated charger.

With respect to using a Lithium-ion battery, I did an experiment using one packaged in a “9 Volt” case for the USA Trains Caboose. The caboose is intended to have the user semi permanently install a pre-charged 9 volt Ni-Cad type battery. Because the caboose includes a keep alive charging circuit meant for the Ni-Cad, I isolated the Li-ion battery with a diode and connected it externally to the caboose for the experiment - with maybe at a later date putting it in case under the car body.

USAT Bay Window Caboose Li-Ion Battery Test

Of course, the caboose only has the one rear flashing light, so the charge on the battery can last a long time.

-Ted

#20

Last September I posted about a new combine for my CC&R layout. I incorporated an internal 14.8 volt 2600 mAh Li-ion battery hidden in the baggage compartment of the combine. A small switching regulator provides a constant 12 volt output for LED lighting. I used three LEDs in series with a 150 ohm resistor. A toggle switch under the floor turns the lights on and off. The regulated 12 volts is routed under the floor to the rear of the combine to connect to following coaches. Each coach will utilize three LEDs in series with a resistor, just as in the combine. The regulated 12 volts will pass under the floor of the following coach to subsequent coaches. In this manner, any number of connected passenger cars will be illuminated from the same battery. Here is the link to the original post:

http://largescalecentral.com/forums/topic/27343/a-new-combine-for-the-cc-amp-r