My Personal Experience with DIY Lithium Ion Battery Packs 2006 to 2012

[R and K RR Products]

   Bill

  It's good to here that the battery is OK

Rodney

[Dave]

Just ordered 4 Batteries and 4 Holders from the Website in Hong Kong that you posted Bill.
Free delivery and a great price. I think my "Annie" will run much better and longer on 14.1 volts, can't wait!

                      Cheers

                           Dave

[Loco Bill Canelos]

Dave,

I'm glad you figured out how to get them in NZ.  Be sure to give us a report.

I hope to do some runtime comparisons next week using an Annie if I can find the time. 

Bill

[NarrowMinded]

Hey Bill do you sand the end of the batteries with fine sand paper before you solder them? I find it helps to just give them a quick scuff then wipe them with a paper towel that has a small amount of flux on it.

NM-Jeff

[Loco Bill Canelos]

Jeff,

It definitely is a good idea to roughen up the surface of the positive end.  I always flux as well.  I have a 15 year old tin of flux(almost gone) which seems to work better than a new plastic tin of flux I just bought.  I don't know why though. 

I am putting the finishing touches on my report on battery boxes and will post it this morning.  In the future I wlll use battery boxes in any situation where they will fit rather than solder.

Bill

[Loco Bill Canelos]

Hi all, Here are a few more things to add to the info noted in my first post.

The picture below is one of the GTL 3.7 volt 5300 Mah cells with the cover stripped off.  You can see how the PCB is now enclosed within the metal case (bottom left end) on the negative end, when compared with the Tenergy cell picture noted in my first post.  This should offer better protection of the circuit if the battery pack is dropped.


My battery boxes arrived from www.ledsupermall.com and the quality seems similar to the ones you can get at Radio Shack or All Electronics for AA & AAA batteries.   I only ordered the ones that hold four seen in the picture below:

You can also get the boxes in 1, 2, or 3 cell sizes.  I wish I would have ordered some 2 cell sizes as it would be simple to tape them back to back to get a square configuration. In any case the possibilities are endless.  The next picture shows the battery box pack and one of my soldered flat packs side by side.

Putting the cells in the holder only added about a quarter inch to the width and an eighth of an inch to the top, and an eighth inch to the thickness.  It took just 20 minutes from the time I opened the package to set up three 14.8 Volt Battery packs and test them. Using three boxes would make a super size pack just as easily. Just solder on your favorite connector, no soldering to the batteries, pop them in, put them in your loco or battery car and off you go.  Actually you could use some type of solderless electrical connector and there would be no need to solder at all.  The only disadvantage to these holders so far is that the batteries can fall out very easily.  I just wrapped one length of white electrical tape around them and that took care of it, and also gave me a place to jot down the info I like to have on the pack.
So the cost for one 14.8 volt 5300 mah battery pack is $2.50 for the battery box, $12.80 for the batteries and $1.20 for the connector I used, or a total of $16.50 apiece.   The lowest cost I found for a commercial built up pack from a RR hobby manufacturer was $54 for a 2200 mah pack not including shipping, the lowest cost from All-battery.com was for a 2200 mah pack $40.82 including 13.62 shipping and $1.20 for my connector.  It is easy to get to like $16.50 and no soldering to batteries!!!

Bill

[R and K RR Products]

   Well I bit the bullet and ordered 10 each of the 2 and 3 cell, and 5 of the 4 cell holders. 
This will make it faster to make the packs and easier to change out a cell if one should
go bad.
I will most likely still have to make some custom packs for the 2 truck shays, climaxes and a heilser that
I have.

Rodney

[R and K RR Products]

  Well my batteries arrived today and soldered up 2 18.5 volt packs. Out of the first 5 packages (shipped 2 cells to a package) I opened up, on one I could not get any voltage. It went on the charger and it is OK. The voltages raged from 3.9 to 4.2 on the rest. Sometime this week I'll check some run times with some of the K's. On my Accucraft K-28 I can get about 2 to 2 1/2 hours run on the Ni-MH 4200 mAH that are still in it. I will make a pack for it and see if these battery will last any longer.

Rodney

[rslater]

Rodney,

I was reading the manual on the Tenergy charger that you use.  I am a bit confused.  I see the balance port and the small board attached.  Since there are various sizes of connectors on that board, how is it connected to the battery pack?  Am I missing something?

I did not want to order until I had some questions answered.

[R and K RR Products]

  Rick
I use Aristo type connectors that I get from All Electronics (polarity is reversed of Aristo though) on all my battery packs and I use type "N" charging ports from Radio Shack for charging onboard batteries. I make my own charging cables with banana plugs from RS with these connectors on the ends.
Here is one hooked up for charging onboard batteries.


If your going to use the cell holders, if I were you, I'd just buy a cheap 4,5 or 6 cell smart charger from All-Battey and go that way for now. They are a lot easier to use cause it is a pain to program the TB6ac that I have.

Rodney

[rslater]

Thanks Rodney,
I think I will stick to my smart charger from Cordless Renovations.  Hope to be sending my K soon.

Rick

[R and K RR Products]

  Rick

Yea if you got one of those chargers, stick with it.

I'll be looking for the motor out of your K then

Rodney

[Loco Bill Canelos]

Here is part 3.  Good News Bad news

Lithium Ion battery pack runtime test.
Some sources say the GTL 3.7 volt 5300 mah battery cells are not really 5300 mah.  To date I have found no article which offers any kind of evidence that they are or are not 5300 mah.  I decided to try a test of running time using the GTL 5300 mah cells against the running time of the Tenergy 2600 mah cells and the Tenergy 2200 mah cells.  I used a 14.8 volt battery pack made up of each brand.  The thought being that the 5300 mah pack should have about double the running time of the 2600 mah pack and the 2200 mah pack should have about 15% less running time than the 2600 mah pack.

To test it out I used a well broken in Bachmann Anniversary 4-6-0 with the Version 5 Chassis equipped with an Aristo-Craft Revolution on board receiver and a Phoenix sound system.  I hooked on 5 Bachmann Jackson and Sharp passenger cars.  For the test I disconnected the lights in the cars.
I ran the test on my indoor layout which is a roughly 50 foot by 10 foot layout laid out in a modified dogbone style.  The main line track is dead level, mostly curved track of five foot radius, or ten foot in diameter.  There is probably not more than 20 feet of straight track.  I feel these conditions will give the reader at least some idea how the battery packs perform.  Runtime on layouts with grades, or tighter curves will be lower, and longer on flat layouts with wider curves and lots of straight track.

I charged each battery pack just before putting it in the locomotive for the test. All packs checked out between 16.64 volts and 16.69 volts at the start of the tests. Using the Aristo-craft Revolution allowed me to have precision measurements of the speed of the locomotive.  I conducted each test at the speed setting of 45 on the Revolution transmitter.   All tests were continuous running with no alteration of the speed, the sound was on in all tests.  Each type of pack was run twice.

As you can see the results are clear.  The GTL 5300 mah battery cells are clearly not 5300 mah but most likely only 2600 mah. The base line running times for the Tenergy 2600 mah pack was 6 hours and 27 minutes and the times for the GTL 5300 pack was actually about 10 minutes less.  The Tenergy 2200 mah pack delivered a runtime of 5 hours and 16 minutes.   During the testing I had another Tenergy 2600 mah battery pack fail it too, was about a year old.  All four of my Tenergy 2200 mah packs still work fine after over four years of use.  I have been unable to figure out why two of my four Tenergy 2600 mah pack failed after only a year of use.

Lessons learned:
Testing runtime is very boring!!   I did learn that Lithium Ion batteries do slow down considerably the longer they are run, it is not as discernible as with NiCad or NIMH cells but it is there.   In my tests I checked the time it took to make a lap at the beginning of the test and at each hour thereafter.   By the fourth hour the time per lap decrease was noticeable to the eye without timing.  In real life running I realized that as time went on during a session I was subconsciously increasing the speed to make up for the slowdown without even realizing it.
Overall Conclusions:
The GTL and Tenergy products have good runtime and the protection circuits worked as they are supposed to in the tests.
The GTL packs, in spite of the fact that they are not 5300 mah are still the lowest cost option when making packs.
It is hard if not impossible to rely on battery specifications from Hong Kong or Chinese suppliers.   

Battery packs made without soldering using battery boxes performed equally well as soldered packs.

Making "do it yourself" battery packs is easier than ever using battery boxes and they are only slightly larger than soldered packs.
 
The GTL packs do have the protection circuit encased within the cell casing which offers better protection if dropped.
 
Use of battery boxes will allow easy diagnosis and replacement if one of the cells fails and will also provide better protection of the cells if dropped.

There is great risk of ruining a battery pack if it is overly discharged.  Once you determine normal running time for your situation it is far better if you stop your train and recharge after using no more that 90 % of your normal runtime.

I am concerned that two of my four Tenergy 2600 Mah packs failed after only about a year in service.  These are the same batteries used in some expensive packs sold by a garden railroad electronics supplier, but under their own brand.

Well that is it for now, I am going to play with my trains rather than test any more batteries!

[R and K RR Products]

   Bill
  Thanks for your work in testing these batteries.  Even if they are only 2600 ma, they are still cheap at only $3.20 a cell and is about 1/2 the price of the Tenergy 2600 ma cells.

I wonder if it will get any better after a few cycles on the packs.

Rodney 

[JerryB]

WOW Bill!!

Great test with really excellent methodology.

Thanks for applying your usual great detail and precise work to this very current and fast moving subject. I know this information will be of use to many (including myself) who have questions about the performance of Li-Ion battery packs.

Now you deserve to be able to just go play trains!

Jerry