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

Started by Loco Bill Canelos, April 22, 2012, 07:50:04 PM

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Loco Bill Canelos

Rodney,

Sorry to hear the bad news!  I agree it is probably not the chargers, Did you try charging them up individually before making the pack??  I would definitely try charging them individually.  Also if you got one too hot while soldering you may have damaged the protection circuit.  I usually test each battery first, then make the pack using known fully charged batteries.  If something fails after making the pack, it is more than likely something I did wrong.  When ordering the chargers from All-battery.com consider getting the one with switches that allows you to charge 1 , 2, 3, or 4, 3.7 volt cells, that way you can safely charge one cell at a time.  Since you are making 18.5 volt 5 cell packs, the 5 cell chargers are fine, but only allow you to charge all five cells as a pack, not individual cells. You can definitely do damage to a single cell trying to use a multiple cell charger, so don't even try it.  You may also have triggered the short circuit protection without realizing it; it some, but not all cases, waiting awhile then trying to charge the cell individually may bring it back.
here is the link for the charger I mentioned.  Shame they don't make one with 5 positions.
http://www.all-battery.com/universalsmartchargerforli-ionpolymerbatterypack37v-148v1-4cells.aspx

I have been running my GTL packs every day since I made them, and so far so good, no failures, all charge fine. 

Share what works and what doesn't !!

Bill



Loco Bill,  Roundhouse Foreman
Colorado & Kansas Railway-Missouri Western Railway
Official Historian; Bachmann Large Scale
Colorado RR Museum-Brakeman-Engineer-Motorman-Trainman
There are no dumb or stupid questions, just questions!

Dave

Hi all, I recieved my Batteries and Holders a few days ago and today Tested them out in my "Annie". Pulled three J/S coaches with some passengers up an down my 3% grades and one is also on a 8ft diameter curve.
           Batteries were Ultrafire 4000mah PCB and pack was reading 16.8 volts at the start of my test run of 2 hours continuous running at 65% Throttle. The battery pack was reading 15.6 volts when I stopped running. A good result I thought.

                  Dave
                   Waikino

R and K RR Products

   Bill
Yea I tried to charge them individually and both charger responded with a open circuit. I only made 2 packs by soldering them.  At the time I made the 2 packs I only checked the first 10 that I took out of the bag. Then when I received the cell holders I checked the rest of them and found these two. I told the supplier that they could wait till I do another order to ship the replacements.




This weekend I'm going to convert one of Kristi's (wife) shays to battery with Aristo Revolution and a P8 sound board. This is one of new releases so we'll see if it truly plug and play. It has a factory installed speaker so that will be a big help too.

One of the packs that I built is in a early DRGW Bumble Bee converted to a Annie with Airwire, P8 and a Sluthe smoke generator. I have about 2 hours on it and still going strong (only run with the smoke on for about 30 minutes). I'll wait till she stops to charge it and see how many amps it will hold on the first charge.
This is going to be my traveling locomotive as it is the smallest that I have and shouldn't have any problems on most layout we go to.




  Rodney
Trying to make a better world for the 20.3 modeler

George Shyavitz

Bill,  are you the William Canelos from Truxton whose "Battery Packs Demystified" article appeared in the December 2012 Garden Railways?

If you are, it's a great article and seems to be a much better solution thatn buying li-Ion packs from Aristo that go bad.

I do have one question about the GTL 5,300mAh batteries.  I found them on eBay, and like your article said, the vendor says they do not have built in PCB protection.  But said, after opening one up that they really do.  How can you tell that it was built into the metal enclosure?    ???
George Shyavitz

Loco Bill Canelos

Yes George, I wrote that article, one way I found out is by tearing one apart but that destroys the battery. The GTL which I bought and though were NOT protected.  I wiil reply in more detail tomorrow as I am not feeling well right now. and give some more tips that I have learned since then.  Bill
Loco Bill,  Roundhouse Foreman
Colorado & Kansas Railway-Missouri Western Railway
Official Historian; Bachmann Large Scale
Colorado RR Museum-Brakeman-Engineer-Motorman-Trainman
There are no dumb or stupid questions, just questions!

Loco Bill Canelos

George, Sorry about my poor post yesterday.  The GTL brand batteries noted in the article were not advertized as having a protection circuit but when I got them the lettering on the batteries indicated they were.  I can no longer find that Brand. The Tenergy Brand from all-battery.com are priced fairly well but shipping costs have gone up.

Shipping batteries is now more costly because the US Post Office no longer allows shipment of batteries by mail apparently some have shorted out in transit due to poor packing.  Orders placed with Hong Kong based sellers do seem to come through the US Mail. although shipping has gone up in many cases. 

The way I test Lithium Ion batteries that say they have PCB protection is to put them in a pack and run them till they shut down. I then use the meter I mentioned in the article to measure the voltage on each individual cell, they should read about 3.0 volts or very close to it, but not lower than about 2.5 volts.  It is harder to test the upper limit because most chargers sold for these batteries will automatically stop charging at a safe limit. The top charge for each individual cell  should not be higher than 4.33 volts.  If an individual cell reads much above that it will most likely not have a PCB circuit.  If you have made up packs, the shut down voltage should be close to 12 volts and the upper limits no more than about 17 volts.  Most smart chargers will stop charging when the pack reaches 16.25 to 16.5 volts.  You cannot properly test individual batteries while connected in  pack. 

All recent Lithium Ion cells produced in the last three years do have a special internal circuit which will shut down the battery if it overheats.  This circuit is designed to prevent cells from overheating to the point of rupture or causing a fire.  Once triggered the cell is ruined.  I mention this because of all the hype put out by some that these batteries will blow up and cause a fire.  The technology has solved that problem in small cells like the ones we use.  That is not to say you should not follow the instructions and warnings that come with your batteries.

The biggest danger to your batteries will be discharging them below 2.5 volts which may eventually ruin the cell.  A sure sign of this is if you try to charge the cell and it will not charge.  Over time I have learned to know when the batteries are about to cut off.  You can tell they are about to shut down when on a particular segment of track you have to increase the voltage more and more to the loco to maintain the same speed as when you started.  I usually stop my loco and change batteries before they shut down to avoid any possibility of too low a voltage.
 
Maybe some of the others have a way of testing that will be helpful, it may seem like I am a battery expert, but I only report from my own experience not that of an expert in battery engineering. 
There are some newer battery HOLDERs which have a built in PCB protection circuit, you can use either protected batteries or non-protected batteries in them without a problem allowing you to buy the lowest cost batteries available and have the assurance of being protected.  Here is a link to them on Ebay, I do not know of a US provider.
http://www.ebay.com/itm/380597615726?ssPageName=STRK:MEWAX:VRI&_trksid=p3984.m1438.l2661
I have not tried them, but the specs look very good.  You have to scroll way down to get to the specs.  They are about 16 buck per holder, but once purchased they can be used ovr and over.  If anyone has tried these please post your experience.   

I did not mention in the Article that I tested 18650 lithium Ion cells by dropping them repeatedly and even throwing them down hard.  I did it at least 60 times with no fires and no explosions and no rupturing or swelling of the cells.  Doing this did eventually ruin the internal PCB.  I also chucked one in a vice and hit it with a hammer again no problems other than ruining it.  I chucked another one in the vice and drove a nail through it again no horror of explosions.  All the time I was wearing leather safety gloves , vest,  chaps and a full face safety mask.  The comments in GR putting fear into those who use these batteries is largely unfounded with the more recently manufactured cells. No matter safety first and following instructions is the best bet.  My wife charges her Lithium powerd devices on a flammable surface all the as do many folks with cell phones.  The improvements in this technology have been such as tom make things safer and more powerful.  Other lithium technologies seem promising but for now are very expensive. 

Bill
   




Loco Bill,  Roundhouse Foreman
Colorado & Kansas Railway-Missouri Western Railway
Official Historian; Bachmann Large Scale
Colorado RR Museum-Brakeman-Engineer-Motorman-Trainman
There are no dumb or stupid questions, just questions!

Gandy Dancer 1

Hi Bill,

Just want to express a big thanks for this really useful info.  Bravo!

Bill (Gandy Dancer).