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OK, I've finally seen the light and I'm switching to battery. I currently have one battery car that uses 18V Milwakee drill batteries. These are too big however to fit into a tank car or a coal hopper (without modification). So, I'm looking for an alternative before I invest in new batteries, chargers, and multiple battery cars. I've looked at the Aristocraft Li batteries, but they take overnight to charge. This won't work either. I like the Milwakee setup, but really want to avoid a box car on my tank unit train. What are others doing and what is the best overall battery system to work for multiple battery cars? Please help!
 

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What's best? Kind of like what's the best locomotive. :)

I have been using NiMh 12V 1500 mah and 14.4V 4000 mah battery packs in the past, but I am now converting over to Lithium-Ion 14.8V 2200 mah and 4400 mah packs from All-Battery.com. The charger is low cost ($25), charge times are quick, and the batteries are light weight. So far, I am pleased with them.
 

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ha ha ha... I have to chuckle, please excuse me...

The battery wars will commence shortly!

OK, serious...

First, I think the Aristo batteries do not take overnight to charge, but ignore that, you can buy fast chargers for ANY type of battery.

Now, you can have:

1. Sealed Lead Acid (SLA), also known as gel cells
2. Nickel Cadmium (nicad)
3. Nickle Metal Hydride (NiMih)
4. Various forms of recharageable Lithium batteries (Li-ion, Li-po, don't fret about the difference).

I have placed them in order of increasing cost, 1 is cheapest, 4 is most expensive.
I have also arranged them in terms of increasing performance vs. size... 1. is largest and 4 is smallest in terms of volume.
I have also places them in terms of weight (for a given amp hour rating) 1. is the heaviest, 4 is the lightest.
and finally, they are also in order of cost.

So first of all, the more money you spend, the smaller and lighter you get.
Second of all, fast chargers get more complex and somewhat more costly as you go from 1 to 4.
Finally the danger from overcharging increases as you go from 1 to 4, although the only one that is really spectular is lithium based, can break into fire, and agressively enough to be like an explosion.

Now, you can safely charge all the battery types given reasonable caution and a good quality charger.

If you are pulling a trailing car, you can basically pick anything you want, 2 big heavy 7 amp hour 12 volt batteries will fit inside and run your trains way longer than you will probably be awake each day.

Basically if you have 18 volts or higher and over 2 amp hours capacity you will probably be fine, but EXACT estimates of run time are IMPOSSIBLE to predict unless you have a system already measured.

If you want your battery car to be a tank car, then numbers 2 or 3 will work, and certainly #4.

Since you are probably talking a custom made battery pack, I would recommend nickel metal hydride cells that you can fit inside, with solder tabs so you can make you pack custom fit. PAck all that will fit, do not agonize about the exact amp hours, just pack it it.

There's my opinion and suggestions.

Regards, Greg
 

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Ed,
I started years ago with Ni-Cad, then switched to NiMH, A couple of years ago I started switching to Lithium Ion batteries, all batteries should probably be slow charged overnight for the longest battery life.....
What I've done with the Lithium Ion batteries because they are so small is unplug the drained battery and plug a new one in.....
Here is where I've bought my....batteryspace.com and all-battery.com.....
 

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Greg.

Ed should also take into account the life span, in terms of how many standard rate re-charges it can take.

Just one example is; Good quality NiCd cells claim to take 1,000 cycles, whilst NiMh claim to take 500 cycles.

Likewise, Ed should also take into consideration that the faster you charge a battery, of any sort, the shorter the life span of that battery will be in terms of the number of re-charges it can take.

When it comes to NiCd and NiMh chemistry it is my experience that Japanese made cells outperform Chinese made cells, in terms of re-charge cycles and run times.
 

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I'm with Del and Dean on this one! I am using 3.7 volt 2600 Mah batteries with built in PCB protection. The cost to build a 14.8 volt pack is $30 bucks. This is NOT expensive. I too get them from all-battery.com. The cost is higher if you want built up packs instead of making your own. In spite of all the horror stories about li-Ion batteries, they are no more dangerous than other batteries. All battery systems are dangerous if they are mis handled, thrown on a fire, cooked in a microwave, or drilled into, etc etc. I solder my batteries using a hot iron (250 watt) plenty of flux, and I get in and out quickly. With Li-ion packs you get the same punch as in two 7.4 volt Nicad or Nimh pack, but with greatly reduced size and bulk.

Take a look at this: http://www.all-battery.com/4tenergyli-ion1865037v2600mahrechargeablebatterieswithinternalpcb.aspx and compare it with NIMH or NICads
 

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I've played a lot with batteries and model airplanes with all chemistries.... Lithium revolutionized our competition ready to fly R/C 10 ounce freestyle aerobatic models. I’ll have to stir the pot and try and recall all the stuff we learned over the years. I’m sure it will come back to me as write my thoughts below.

All of the aforementioned chemistries will work fine, some are better suited to form fitting and lighter weight but lack punch and staying power and are simply volatile while others are heavy yet durable don’t need much attention and provide stable discharge curves and are cheap too!. Energy density is paramount for model airplanes, trains don’t really care heavy or dense cells are the most robust… Some of the KEY factors in cell chemistry choices are energy density, charge retention, memory, charge/discharge cycle life and the more obvious discharge or performance curves. While not all the “best” aspects of specific chemistries are paramount for a given hobby some are definitely more suited than others for given applications.

NiCd’s are well suited; lowest internal resistance, durable, cheap, flat discharge curve, long life, NiCd doesn’t require fancy chargers and are safe….

NiMh’s are much like NiCd’s, however energy density is better, more expensive per Ah of capacity, less tolerant to abuse, requires more sophisticated chargers, forming or training is paramount (C/10 @ 20-24hours with at least three full charge/discharge cycles), Ni-MH capacity falls off with cycling (USE) whereas Ni-Cd stays pretty constant, seldom going below 80% before shorts develop. Ni-MH has a higher self-discharge rate (3-4%/day) than Ni-Cd (1%/day).

Lithium most expensive per Ah of capacity, energy density is (5) times that of other chemistries, fragile by some standards, form fitting is great, very sophisticated chargers required, volatile (thermal runaway) if charged incorrectly or with the wrong charger, less than half the cycle life others, don’t like to be subjected to or perform well under high discharge demands yet they have the best self discharge curves of all noted thus far.

Every chemistry has its specific quirks and requires its own specific type of charge regimen, all require maintenance some more than others. When Lithium was first brought to RC world we experienced multiple user miss-haps resulting in spontaneous combustion due to user interaction with miss-information, wrong charger type/charge parameters and expectations.

The best results for any chemistry is typically realized with lower charges rates. All of the chemistries listed above less PB/Gel/Lead must be used in multiple cell configurations or are stacked in series and or series-parallel to achieve ampacity/voltage numbers as required/desired. Periodic extended slow charge rates at C/10 hour rate allow the cells to percolate so to speak allowing all cells to balance themselves. Pretty much across the board cells are charged once they reach peak voltage respectively (in pack configurations ill balanced cells provide false peaks), fast charging does NOT realize good results in this consideration. Remember a battery pack is only as good as the weakest cell accordingly cells that have been graded are the best choice for pack building (maybe not really a factor in our hobby though).

“slow charge” The industry standard is any charge rate that will charge the cells in 10 hours or less.

"fast charge" The industry standard is any charge rate that will charge the cells in 1 hour or less.


This term "C" is numerically equivalent to the rated capacity of a cell. A cell discharged at the "C" rate will expend its minimum capacity in one hour.

At .25C discharge rate, a cell's one hour rated capacity will be delivered in four hours, and at the 4C discharge rate, the rated capacity will be delivered in 15 minutes. For example, the "C" rate of a 2400 mAh cell is 2400 mA. The .1C discharge or charge rate for this cell would be 240 mA or .24A.

Dollar for dollar, long term use and user interaction you simply cannot beat NiCd’s IMO… I don’t have much experience with PB/Gel/Lead cells perhaps they are a very good consideration if weight and size are not a factor such as a battery box car or the like.

It’s entirely plausible I made some mistakes in my comments above, It’s been a while…

Regards,
Michael
 

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Great comments Michael.

AA and AAA size cells now have a hybrid Alkaline/NiMh chemistry available. The Sanyo brand name is ENELOOP. These were developed specifically for digital cameras and are guaranteed to hold 85% of their charge for 1 year. My testing so far confirms this claim. Although they do not overcome the problems of discharging at too high a current. See below.

Permit me to add few more observations regarding cell sizes.
In Australia the only affordable cell sizes readily available are AAA, AA and SubC. Other sizes are avilable but they are extremely expensive. Neither do we have specialist battery suppliers such as Battery Workd mentioned above.
Sub C cells can handle high discharge rates but the abillity of some SubC cells to do this depends on the actual cell. They are not all the same.
I have found that, because of their internal construction, AA size cells cannot handle much more than one amp discharge rate, without seriously reducing the number of re-charge cycles they can achieve. You should only ever use AA size cells in low current draw situations.

Sanyo say that users MUST NOT charge or discharge NiCd cells in parallel unless the cells in each pack are protected against feedback from the other pack by suitably rated diodes.
 

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Bill,

While I'm not trying to be an arse, you are comments on the potential for problems with Lithium battery chemistry are miss-leading. Lithium cell chemistry is and can be very dangerous, much more so than any other chemistry noted!!!!!! While the charge monitoring gadgets you note are beneficial in reducing exposure to problematic chargers or regimens they are not the Holy Grail and worst yet they are an accessory. So not all battery manufacturers provide same, I suspect due to cost for the most part.

The Lithium Ion 18650 cells you note are great cells and probably the most tried and tested cell in this configuration to date, that said they are not capable of high discharge maybe C2 if I recall sustained for short duration. Somewhere I have performance data I garnered personally on my programmable electronic load with PC data interface. We’ve used the 18650 cells exclusively for many years as on board flight packs for R/C model airplanes. The 18650’s are typically configured in series-parallel configuration to realize 7.4V packs @ twice their rated mAh capacity; 2 x 2600mAh = 5200mAh. This means we use two pair of two cells wired in series to double the voltage (3.7V x 2 = 7.4V) and then wire the pairs of two in parallel to double capacity. The reason I bring this up is we found the cells simply did not provide the simultaneous on demand power required of multiple high power digital servos, in fact GS (giant scale gassers use two parallel-series packs at the very least (5200mAh x 2= 10,400mAh), my point is the batteries simply do not fair well when much (amperage) is asked of them. I proved this in my own testing with the aforementioned electronic load and recording device. FWIW, the 18650’s fall flat on the face when you introduce a C1 load momentarily and then flatten out and then sustain about C2 for about twenty minutes (if memory serves me) before the discharge voltage dips below the recommended cut-off number, (which presntly evades right now).

All that said our trains don’t see spontaneous demands for high current draw for very long, and I’m guessing current spikes are only realized when the hammers dropped and they last for micro-seconds. Prototypical operation would not garner the need for high current needs either, so the lowly ability of the 2600mAh Lithium-Ion 18650’s suffice for most. Sometime in the future I’ll put a data logging DVM in a loco and see what the demands really are as required under load on the rails of various locomotives.

If you’d share I’d be interested in approximate run times with what equipment you’re realizing with your 18650’s for discussion.

Regards,
Michael
 

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Tony,

I'm trying to recall, but .6% per day comes to mind as the loss realized typically of lithium cells (I not mentioning nor including the electrical losses realized of the cell monitoring safety gadgets). This is a plus but their cost together with a special charger, high internal resistance which increases with age mitigating predictable continuous capacity loss, limited shelf life (from date of manufacture, regardless of cycle life) and lack luster performance makes me wonder why I’d go there, especially when most loco’s seem to benefit from the additional un-sprung weight. Any who I have lots of these cells floating around and will throw some in a loco to see how the real world treats same, probably USAT diesels will be a good test bed.

So the new Sanyo offerings are intriguing, sounds like all the benefits of NiCd with even better self discharge curves.

Your spot on with your comments on the smaller cells, the sub-C cells do nicely for our needs IMO… And yes not all sub-C’s are created equal, but this is true of all cell types and sizes. The best batteries and prices for our needs are generally offered to the R/C industry in my experience. Matched or graded cells (cells that are subjected to cycling regimens and then grouped in like lots of capacity and sustained high voltage numbers) offer the best performance and you pay a premium for same. I’m thinking a good quality Sanyo sub-C cell is hard to beat for many-many reasons and all we really need as our loco’s are far less demanding than battery powered R/C cars, boats and planes.

Regards,
Michael
 

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Michael.

The ENELOOP AAA & AA cells are replacing Sanyo NiMh chemistry. Panasonic has a similar product.
Both Sanyo and Panasonic no longer make those size NiMh cells.

I too think NiCd SubC cells give the best value for the money both in terms of performance and the number of re-charge cycles they can attain.
The largest capacity I can get here are nominally 2,400 ma but they regularly record 3,000 plus on my Maha charger.

I accept that there are limited run times with 2,400 ma. However, there are two very simple alternatives to overcome lack of run time:
1. A very simple circuit that utilises the battery charge port to accept an auxillary battery, or batteries, in a trail car. Plugging in the trail car battery automatically disconnects the on board battery.
2. Double, or even triple, up the packs in parallel in the loco via diodes or a selector switch to increase the on board capacity. Again there are simple circuits to charge each bank of packs separately.

Please understand I am not condemming Lithium chemistry. I have zip experince with it other than the successful application in my Nokia cell phone.
 

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Posted By Del Tapparo on 03/07/2009 6:08 PM
What's best? Kind of like what's the best locomotive. :)
I have been using NiMh 12V 1500 mah and 14.4V 4000 mah battery packs in the past, but I am now converting over to Lithium-Ion 14.8V 2200 mah and 4400 mah packs from All-Battery.com. The charger is low cost ($25), charge times are quick, and the batteries are light weight. So far, I am pleased with them.


Hi Ed... Like Dean and Del, I've been running 14.8 Li-ions for 2-3 years with very good service. 14.8 4400 mah Li-ion from Battery Space and Same Battery Less Money All- Battery.com. The 1.5 amp hour charger is the one to use. 1.5 Amp Hour charger. That's the most important thing to do. USE THE RECOMMENDED Charger and nothing else.

I use this R/C car plugs for my connectors. This end for the battery. This end in the locomotive or battery and charger car. They are all polarity the same regardless of manufacturer. Some of the other smaller connectors can have the polarity reversed from batch to batch.

I would recommend the 4400 mah batteries for larger diesels. I do use some of the 2200's for my single motor locomotives with great success.

I'm still running my large diesels with 12 volt gel cells in series to 24 volts.
 

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Hello Mr. Harvey,

My name is Rick Isard, I'm the owner of Cordless Renovations. At Cordless Renovations we manufacture NiCd, Nimh & Lithium-Ion batteries for G Scale Trains. We also manufacture a new charger that fits right into your existing gondola, box-car, or tender and will charge & operate your train engine and it's called the CR-1 Smart Charger. When you have time, why don't you give me a call and let's talk about what's best for your system.

Rick Isard, owner
Cordless Renovations
Office: (319) 366-7294
Email: [email protected]
Website: www.cordlessrenovations.com
 

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Depends on how you figure "Best." I went for AmpHours / Dollar and have 3800mAh NiMH packs. They're really big, but I have lots of space in the tender. I'll need something different for my Annie.


Nice to see you at MLS, Rick. 
 

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I had an interesting thought about charging cycles vs. type of battery. If I have a ni-cad with 1000 recharge cycles and replace it with a comparable sized (physical) ni-mh battery with 500 recharge cycles, I probably have about the same amount of run time hours, don't I??

Ed
 

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Posted By eheading on 03/12/2009 12:55 PM
I had an interesting thought about charging cycles vs. type of battery. If I have a ni-cad with 1000 recharge cycles and replace it with a comparable sized (physical) ni-mh battery with 500 recharge cycles, I probably have about the same amount of run time hours, don't I??

Ed




Given two battery packs of equal physical dimensions, the NiMh would have a longer run time than the NiCad by about 30-50%. NiMh batteries have a higher energy density than NiCads. That means for the same physical size you get more mah (milliamp hours) of run time. The trade off is you get fewer charge cycles; the NiMh won't last as long. But the number of charge cycles has nothing to do with run times, only battery life. For some great information on batteries, go to Battery University
 

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Posted By eheading on 03/12/2009 12:55 PM
I had an interesting thought about charging cycles vs. type of battery. If I have a ni-cad with 1000 recharge cycles and replace it with a comparable sized (physical) ni-mh battery with 500 recharge cycles, I probably have about the same amount of run time hours, don't I??

Ed



Another factor you need to consider, is the rate of self discharge of NiMh compared to NiCd.
 

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I like the NiMH batteries best. They provide sufficient current density and are sort of middle of the road in price. They might be rated at 500 cycles. That is full charge/discharge cycles and that is quite a bit of train running.

They do leak down more than NiCad's but all you have to do is top them off before running and off you go.
 
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