Large Scale Central

How do ya know when your LiOn is dyin'?

Electronics Power and Sound
#1

OK, I got my Tenergy 14.8 volt, 2600 mAh battery installed in my Bug Mauler tender. Charged it up on my Tenergy charger 'til the red light went out. Works great.

BUT…how will I know when the batt has discharged itself? I’ve read horror stories about LiON batteries and I think it said you should never kill it (i.e. completely discharge it).

Fortunately, I did wire in a charging jack, so plugging in the charger is easy. But when?

Also, do LiOn batts that are not used for some time go bad? Should I run them just for the heck of it? I’m not always running trains, as I have other railroad-related projects to waste my time on–or “on which to waste my time,” for you grammarians out there.

#2

Joe Rusz said:

BUT…how will I know when the batt has discharged itself? I’ve read horror stories about LiON batteries and I think it said you should never kill it (i.e. completely discharge it).

Pretty simple…it won’t move. It’ll still have enough juice to power the lights and sound, but not enough to power the motor. Hopefully it won’t quit on ya in a tunnel…I’ve had that happen.

#3

The Tenergy Li Ion packs include a protection PC board. The board has a circuits that keep close tabs on the voltage and condition of each cell in the pack. When the overall pack voltage falls below the threshold, it shuts off the power. Your Annie will just stop dead in it’s tracks. All you need to do to reset the circuit is charge the pack.

Li Ions have a very long charge holding ability. You can leave a charged loco sit for months and come back and run it without charging. You may get a little bit less run time if it has been sitting for more than a few weeks. It should not hurt them to sit in a charged state for months without use. If left long enough they will eventually discharge to the point where the PCB shuts them off. At that point it’s probably a good idea to charge them. I don’t keep track of mine and out of half a dozen packs I’ve only had one fail, and that turned out to be the PC Board, not the cells that went bad.

I don’t remember what RC system you ended up with. Del’s RailBoss can be programmed to give you a little warning when the pack is about to go down. Because I use different size packs with the same RailBoss I’ve never taken advantage of this feature.

Because of the PCB you can’t overcharge them either. If it’s been a long time since the last charge and you are planning on operating for the day it’s OK to top off the charge. Don’t do this as a habit since Li Ion’s have a limited number of charge/discharge cycles which is enforced within the safety margin by a counter on the PCB.

#4

Ken Brunt said:

Joe Rusz said:

BUT…how will I know when the batt has discharged itself? I’ve read horror stories about LiON batteries and I think it said you should never kill it (i.e. completely discharge it).

Pretty simple…it won’t move. It’ll still have enough juice to power the lights and sound, but not enough to power the motor. Hopefully it won’t quit on ya in a tunnel…I’ve had that happen.

I usually recharge my engines after I’ve used them, especially after a couple of hours running. I’ve had 2 NiMH packs go bad but that was from not running them at all…one was getting repaired and the other I just didn’t find time to run it.

#5

Ken Brunt said:

Joe Rusz said:

BUT…how will I know when the batt has discharged itself? I’ve read horror stories about LiON batteries and I think it said you should never kill it (i.e. completely discharge it).

Pretty simple…it won’t move. It’ll still have enough juice to power the lights and sound, but not enough to power the motor. Hopefully it won’t quit on ya in a tunnel…I’ve had that happen.

Ken, I’ve never had that happen with a Li Ion pack. They just go from working to not in an instant for me. If I have the sound system turned up loud I will notice a definite lack of volume a minute or two before the loco gives up.

#6

I have had it happen. What can I say…:wink:

#7

Thanks guys. Duly noted. Frankly, at this time I won’t be running the loco long enough to discharge the battery in one swell foop. Just some switching moves on the track I’m gonna throw down in the planter. As for using the lights as a gauge, at this point my 10-wheeler’s headlight is still part of the track power circuit, so I’ll hafta pull out the headlight lead and probably attach it to the motor leads. Maybe put a diode in there so the engine’s headlight shines only in forward. If I get ambitious, I’ll figure out a way to activate the tender light when the loco’s in reverse–prolly by tapping into the power lead at the distribution strip and again, putting in a diode.

Jon, I don’t have Del’s RC system, just the little conversion module with its power switch, fuse, and terminal strip that allows you to link your battery to the RC receiver (an old Aristo Train Engineer) and the sound system (a 1997 or so Phoenix without the individually controlable sounds, which my second generation Phoenix does have (Phoenix converted it for me). BTW, these two sound systems were made just before the so-called 2K or something, which came out right about Y2K (i.e. 2000). The other loco is next and I’m already preparing a spare tender shell for the conversion. Thought I’d paint it while I’m at it. And in case you wonder, I have a box of Bug Mauler parts (spare cabs, tender shells, etc) as I have one stripped chassis (converted to a 2-8-0 by Barry) and awaiting a shell of some kind), plus all the junk off a stripped, flashlight battery-powered Mauler I bought just for parts.

By the by, thanks for not busting my chops for my calling it a LiOn battery. Now I know it’s spelled Li Ion. Frankly, LiOn sounds cooler, kinda like “The LiON King,” which is a good name for a battery supply store.

:slight_smile:

#8

While the packs do shut themselves off, you will begin to notice your locomotives becoming just a bit lethargic about 10 - 20 minutes before they do so. Of course, I’ve never taken that opportunity to pull the pack and replace it at that point. I just make a mental note of it in the back of my mind that “gee, my loco is going slow at this throttle setting” and a few minutes later, I’m not surprised when it stops.

One thing to remember; most “smart” chargers will not charge a pack that is already fully charged. So if you charge a pack and sit it on a shelf for future use, then go to top it off, don’t be surprised if the light on the charger stays green. It just means it’s got enough of a charge to where you don’t need to recharge it. There’s no need to replace the PC protection board on the false assumption that you zapped the board. (on the plus side, I got a spare working PC protection board.)

As for charge/discharge cycles, whenever I’ve seen reference to that, the number of charge/discharge cycles is still well into the low 1,000s. Even at once a week–which is a lot of running–we won’t come near that limit for quite some time. (20 years or so to reach 1000 cycles at one cycle per week!)

Later,

K

#9

Maybe 1000 cycles on the expensive ones. The Tenergy pack spec is between >300 and >500 Cycles depending on the pack. I do not know what the hard limit programmed into their PC board is - they won’t tell me and the data sheet doesn’t say.

Source: http://www.adafruit.com/datasheets/31000_datasheet.pdf

#10

Jon Radder said:

Maybe 1000 cycles on the expensive ones. The Tenergy pack spec is between >300 and >500 Cycles depending on the pack. I do not know what the hard limit programmed into their PC board is - they won’t tell me and the data sheet doesn’t say.

Source: http://www.adafruit.com/datasheets/31000_datasheet.pdf

Jon first off let me make clear i’m not a battery expert so i’m just trying to learn. I could not find any where
that tenergy talks about a counter, I always thought that great than 300 was just a number of times you
could charge the battery before the chemistry would start to give up.

Richard

#11

I’m no expert either, but did a bunch of research on the PC boards when I was having trouble with a pack. I can’t recall the source, but I either read in one of the technical documents or was told by one of the tech guys about the board having a counter. It could be bad information - if it is I apologize.

#12

Batteries are often rated in “full” charge/discharge cycles.

On average, LiIon will give you about 400 FULL cycles.

You can get more than double that of HALF cycles, i.e. you charge the battery and then only discharge it half way.

So “1,000 cycles” needs some additional information or it is meaningless.

(by the way, nicads are more linear, if you can get 1000 full cycles, you will get almost exactly 2000 half cycles)

LiIon really does not like to be discharged fully, so you get the most “life” if you charge back up whenever you can.

Greg

#13

Older Lithium technology, if I recall correctly, started dying the minute they were manufactured. They were measured in that life span.
The problem with charging before you put them away, is…how do you know they are stiff full when you go to use them again?
Using a high-rate charger (like a Triton set to 2.5 amps) will cause some real smoke issues if you jam it twice.
There is a really easy way to tell when your Lithoum battery is dyin’: (http://i.dailymail.co.uk/i/pix/2013/01/08/article-2258626-16CC9F4E000005DC-666_636x478.jpg)
http://t0.gstatic.com/images?q=tbn:ANd9GcSemJv8JanfscC9JzfM4jZ9epK6Y5cp4qH2Zm2YD9XvnSE5Cqy7

TOC

#14

Whatever the “limit” on charge cycles is, the point stands that it’s going to take most of us a L-O-N-G time to reach it. I’ve had some of my packs for 4 years now, and if I’m at more than 50 charge cycles on them, I’d be VERY surprised. My oldest pack–a pack in a dedicated locomotive installation–has probably seen one or two charges per year at the most. I know I haven’t charged it this year at all. I get 7 hours operating per charge on that pack, and I don’t run that locomotive all that much.

Later,

K

#15

Mcneely has been preaching this sermon for years. Wrong on so many levels:

Quote:“The problem with charging before you put them away, is…how do you know they are stiff full when you go to use them again?”

Because lithium does not self discharge on the shelf the way Nickel does.

Quote: "Using a high-rate charger (like a Triton set to 2.5 amps) will cause some real smoke issues if you jam it twice.

Wrong again. First off, the protect pcb on the pack, and the smart chip in the properly designed charger will prevent this from happening. If a fully charged pack is presented for charge, the charge current will drop off so fast the charge will terminate very quickly.

Lithium charges differently that old style tech. Lithium charges in stages, and the primary charge function, after initial charge run up, is constant Voltage, not constant current. Setting a triton on Lithium cycle at 2.5 amps means nothing as the current drops off and terminates charge. Dont take my word for it, look it up. Best way to charge and use lithium is to charge to about 85% rated, they will last a very long time that way. This is also the best argument for a really good charger, and not the 20- 30 $ fake smart chargers that many folks use. They work, but will not avoid saturation charge, which is what will shorten the pack lifetime.

Voltage is what stresses the cells in a lithium pack, not current.

#16

Jeeze Jonathan, you sound like a guy with real practical experience as well as a handle on the basic electronics used.

So much "information"bandied about on LiIon is often just old information on nicad cells, and much of THAT is also wrong, like the real reason for “memory”.

Regards, Greg

p.s. for the people that don’t get that as a compliment to Jonathan, it was.