Large Scale Central

How Much Run Time Are You Actually Getting On Your Li-ion Pack?

Modeling Motive Power
#1

I have an AristoCraft FA that I had converted to run on track power or NiCads with the onboard train Engineer so many moons ago. I had 15 “sub-C” cells in that thing but they no longer take a charge.

I want to replace them with 14.8V of Li-ion so that I can run the track cleaner around. I don’t need a great deal of speed for that operation and 14.8 volts should be more than enough.

It is easy enough to calculate the battery life from the amp-hours, but what are people using (e.g., 5,200 mAH) and getting (e.g., 3 hr of actual running) in real life?

Thanks

#2

Todd Brody said:

I have an AristoCraft FA that I had converted to run on track power or NiCads with the onboard train Engineer so many moons ago. I had 15 “sub-C” cells in that thing but they no longer take a charge.

I want to replace them with 14.8V of Li-ion so that I can run the track cleaner around. I don’t need a great deal of speed for that operation and 14.8 volts should be more than enough.

It is easy enough to calculate the battery life from the amp-hours, but what are people using (e.g., 5,200 mAH) and getting (e.g., 3 hr of actual running) in real life?

Thanks

The 14.8V 5200mAHr lipo in my Bachmann 3 truck shay has so far given me over 5 hours of run time and doesn’t look like stopping (I have low voltage protection function on my motor controller). It is also powere a “mylocosound” sound card.

The 14.8V 4000mAHr Lipo in my Bachmann Connie has been running about the same length time again a sound card is fitted.

I do not keep records of run times for my batteries but maybe I should start.

Might give you some idea

#3

I have a 14.4v 5400 mah in my K-27 and I have yet to run it all the way down during an 2 day Ops session. The smaller C-19s and Annies have 14.4 v 2800 Mah and depending on what load they’re pulling between 3-5 hour run times.

#4

I run diesels and have 14.8v, 6400 mah lithium ion batteries in each engine… These run in pairs…

During Ops days, some get cranked up around 10-10:30 am, and are still running at 5-5:30 pm…

I recharge them over night for the next days Ops… Each of my engines has it’s own battery

and receiver installed in them… They pull trains between 14-18 cars long… (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-cool.gif)

#5

Thanks guys. When you say “run times” in hours, are you talking about intermittent running and maneuvering, or just going in a consistent “roundy-round” at a “medium” speed as is done cleaning track? That is my interest here.

#6

I run a 5600mHa 18 volt Lion in my K27 with an Edington gear reducer, and PB11 sound and about 5 lbs additional weight in the smoke box… At shows pulling 10-12 AMS/Bachmann 1:20.3 cars I get typically 3 hours continuous run at about 60-65% throttle.

#7

Bob Cope said:

I run a 5600mHa 18 volt Lion in my K27 with an Edington gear reducer, and PB11 sound and about 5 lbs additional weight in the smoke box… At shows pulling 10-12 AMS/Bachmann 1:20.3 cars I get typically 3 hours continuous run at about 60-65% throttle.

You bring up a good point here.

Does more voltage at the same amperage equate to more run time if you run at lesser voltage than either can put out?

For example, if you run at 12 volts continuously, would an 18.5 volt, 5,200 mAH Li-ion pack last longer than a 14.8 volt 5,200 mAH pack?

In fact, couldn’t the 14.8 volt pack last longer because the engine is hauling less weight around?

OTOH, the 18.5 volt pack provides 96 total watts whereas the 14.8 volt pack provides 77 watts. (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-undecided.gif)

#8

Todd,

Maybe you could look at it this way. My strongest batteries are Airwire’s 6800mah at 14.8volts. That means you could run a loco drawing one amp steady for 6.8 hours. Or a 2 amp train steady for 3.4 hours. There are so many variables that coming up with run time is really hard. Take your FA unit for example. Do you or anyone out there know what the average current draw is on those units? That would give a better idea about run time. I really don’t think you will be disappointed if you install a quality high mah 14.8 volt battery.

#9

Todd Brody said:

Thanks guys. When you say “run times” in hours, are you talking about intermittent running and maneuvering, or just going in a consistent “roundy-round” at a “medium” speed as is done cleaning track? That is my interest here.

Todd my example is intermittent runtime, about 1/2 - 1 hour per run hauling a relatively small train (under 10 wagons), so depending on how long you run the cleaner you make get quite a number of “laps” before needing a recharge.

I agree that you really can’t go wrong with a 14.8V 5200mAhr battery, it should give good service for a fair number years considering you are not flogging it like the R/C care and plane guys do.

#10

Paul Burch said:

There are so many variables that coming up with run time is really hard. Take your FA unit for example. Do you or anyone out there know what the average current draw is on those units? That would give a better idea about run time. I really don’t think you will be disappointed if you install a quality high mah 14.8 volt battery.

Of course. I had forgotten that Georger Schreyer used to document all of this stuff and you just need to know where to look. Seems to be on the order of about 2 amps pulling some cars and I assume that the cleaner would add some drag as the cars do.

http://www.girr.org/girr/tips/tips4/tractive_effort_tests.html

#11

I’m surprised to not see more enthusiast reports on battery run times!

Extracting full rated capacity out of Li-Ion batteries is not recommended by their OEM’s! If you can realize 70% capacity at the discharge levels atypical of model trains while not dipping below 3.0V its all good.

Michael

#12

Today I connected the 14.8V, 5,200 mA battery up in the AristoCraft FA after making the appropriate plugs to make it work and be able to charge it. This is for the active track cleaner I previously made.

It has to be over 15 years ago that I installed the onboard Train Engineer in this engine with 15 C-size Nicads. Talk about a load! The Nicads never lasted and went flat so I pulled them out after the first couple years and the engine has only been run (very rarely) from track power since (switchable).

I cleaned the contacts on the old transmitter and put batteries in it.

When I connected the Li-poly cells and switched to the on-board system, the fan instantly came on. I brought up the speed on the throttle (engine laying on its side) and the wheels started to move and responded to the transmitter controls. I didn’t even have to link the transmitter and receiver after no power for all these years! It just worked right. Boy was I suprised! (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-cool.gif)

“1-Gauge, One Community”

#13

Michael Glavin said:

I’m surprised to not see more enthusiast reports on battery run times!

Extracting full rated capacity out of Li-Ion batteries is not recommended by their OEM’s! If you can realize 70% capacity at the discharge levels atypical of model trains while not dipping below 3.0V its all good.

Michael

Hi Michael,

Could be that a lot of us that run battery - R/C are operations based not roundy round? I charge my locos about once a month if they need it or not! My demand on the batteries is pretty light so I rarely need to charge a battery in the middle of a session.

#14

I agree with Jon, I have a 3x22 foot switching layout and I have only charged my batteries once in the last 4 months and I did that just to have something to do, they were not even close to needing a charge. Those switching guys on the engine do a lot of time BSing between moves, so I think the batteries will last a long time.

trainman

#15

John Lenheiser said:

. Those switching guys on the engine do a lot of time BSing between moves, so I think the batteries will last a long time.

trainman

#16

Jon Radder said:

Michael Glavin said:

I’m surprised to not see more enthusiast reports on battery run times!

Extracting full rated capacity out of Li-Ion batteries is not recommended by their OEM’s! If you can realize 70% capacity at the discharge levels atypical of model trains while not dipping below 3.0V its all good.

Michael

Hi Michael,

Could be that a lot of us that run battery - R/C are operations based not roundy round? I charge my locos about once a month if they need it or not! My demand on the batteries is pretty light so I rarely need to charge a battery in the middle of a session.

I don’t think I have EVER charged one in the middle of a session. I really have NO idea how long they might actually last, but when visiting a layout, I would typically charge overnight “just to be sure”. Did they ever need it? I have no idea. But I was so “paranoid” that I eventually made all my batteries removable, so in case they ever did run out during an ops session, I could just pop in another one and keep going. It never happened, but, boy, was I ever prepared! At home, I would go for months between charges (but only because somebody told me I need to charge them twice a year (and that’s probably more than they ever needed!). To be fair, I never did keep ANY records of any kind, so this is very unscientific. (https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-foot-in-mouth.gif)

#17

John Lenheiser said:

I agree with Jon, I have a 3x22 foot switching layout and I have only charged my batteries once in the last 4 months and I did that just to have something to do, they were not even close to needing a charge. Those switching guys on the engine do a lot of time BSing between moves, so I think the batteries will last a long time.

trainman

That’s NOT BSing! Us operators like to call it what it really is: extended planning! (https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-foot-in-mouth.gif)

#18

The FA that will push/pull the track cleaner is done with 14.8V, 5,200mA Li-poly cells.

The guts secured inplace:

Track/battery/primary charge jack wiring:

I made an extension for the 5-pin plug using an old plug, its wiring and board header from an old VCR. This is how I ran the “cell wiring” for the balance feature out through the lower box side:

And the adapter for the “power plug” connected to the charger.

Now if we could just tuck that 5-pin plug in someplace inconspicuous… This required a bit of trimming on the curved edge of the air cylinder but it is not noticable.

… With easy access:

Voila!

#19

Jon Radder said:

Michael Glavin said:

I’m surprised to not see more enthusiast reports on battery run times!

Extracting full rated capacity out of Li-Ion batteries is not recommended by their OEM’s! If you can realize 70% capacity at the discharge levels atypical of model trains while not dipping below 3.0V its all good.

Michael

Hi Michael,

Could be that a lot of us that run battery - R/C are operations based not roundy round? I charge my locos about once a month if they need it or not! My demand on the batteries is pretty light so I rarely need to charge a battery in the middle of a session.

Calling all Roundy Round runners to please report your battery usage !

Good point Jon …(https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-cool.gif)

#20

Andy Clarke said:

I run diesels and have 14.8v, 6400 mah lithium ion batteries in each engine… These run in pairs…

During Ops days, some get cranked up around 10-10:30 am, and are still running at 5-5:30 pm…

I recharge them over night for the next days Ops… Each of my engines has it’s own battery

and receiver installed in them… They pull trains between 14-18 cars long… (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-cool.gif)

14 -18 cars was so yesterday dad! Pull the antenna up on your flip phone cause I’m calling you now !