Safety Concern Re: Lithium Multicurrent Universal Fast Smart Charger.

[LuxLuthor]

This post was originally a part of this thread. Action was taken as a response from multiple reports of concern by members. - Empath

At the risk of getting a big fat JEER, and with full apologies to Alin in particular, I am urging anyone with this charger, or thinking about getting one to read these two warning threads. Especially make sure you at least view some of the exploding fire videos in my post #113 in first link:

CPF Thread #1

CPF Thread #2


I know it is against the rules to post something negative in a GB thread, but I sincerely believe this is a matter of public safety, and I do not believe Alin has done enough to protect those he is selling this to.

At the very least, people should only use this charger if they are outside where an explosive fire can do no harm. I had hoped that Alin would take some more dramatic steps several weeks ago after I contacted him to protect people buying it.

I also believe that FiveMega should issue EXTREME warnings about proper charging of Lithium Ion batteries in packs such as those used in lights like this. Using protected Li-Ion cells gives some protection when charging, but that assumes the protection circuit chips have not been crushed, dropped, bumped, shorted out, or otherwise damaged. Unprotected cells in a pack like this is like playing "Russian Roullette." Watch the videos.

[Empath]

I've made this concern a spin-off of the original thread. Hopefully, Lux will get his concern across, and the original thread will co-exist without excessive disruption.

[LuxLuthor]

Thanks Empath. I think this is a great way to handle this. I had been using this Alin Li-Ion pack charger for quite a while, and as I started reading about "balancing Lithium cell voltages in packs" I just began to understand how this can lead to serious fires.

In addition to the one member having one of his batteries explode and melt into his carpet, I am sure that I was headed for a major fire when I took out my four UNPROTECTED 14500 Lithium Ion cells that member AWR put into one of FiveMega's 1D maglites to power an 1166 incandescent bulb. I never knew there was a serious danger that could lead to a fire or explosion, until I got these readings from the 4 cells:

Cell #1 - 3.95V
Cell #2 - 3.24V
Cell #3 - 3.89V
Cell #4 - 3.41V

What was in the process of happening with this charger is that cell #1 was being dangerously over-charged because the entire pack of 4 cells gives an average volt reading...and this charger keeps charging until the average cell in the pack's reading reaches 4.2V (or 16.8V total in my 4 pack example) when it shuts off.

What will happen in my REAL example is cell #1 will get charged into FIRE STARTING VOLTAGE TERRITORY, because the lower cells drag down the average pack votage, and make the charger think that all cells are at the same even voltage.

OVER CHARGING an unprotected lithium cell will eventually cause an explosive fire, which unattended could literally burn down your home. Most reports say if a cell is overcharged to about 4.35V that is all it takes to start the 1000 degree F fire.

I got no warning that this imbalance of the cells could happen, and to watch for it from AWR, nor AW, nor FiveMega, nor Alin who sells this unit. My concern is many other CPF users also do not understand this danger.

[max52]

Baiting post removed

Unforgiven

[LowTEC]

The next concern would be, what's the proper way to put out this sort of fire when it happens, for one, I know water doesn't work with metal or chemical fire.

[LuxLuthor]

This danger is way beyond what max52 would imply with his long list. Most people using this charger have no idea what can go wrong, and how easily.

Another aspect of this charger that is dangerous is the poorly designed slider switch is not easy to be sure which voltage setting it is on for the middle two positions. If you tell the charger to apply higher voltage than the actual number of cells in your pack, that almost guarantees it will cause a fire, which happened to a CPF user who posted about it in the battery section.

The Lithium smoke is extremely caustic & toxic if inhaled, in part due to hydrogen fluoride formation, and the best way to protect yourself is leave the area. That is also why it is best to charge Lithium cells in a place like your garage with a concrete floor. If there is a fire, you can open the door and let it ventilate to outside.

The Federal Government is having serious debates about banning all Lithium batteries on all airlines, due to the 4 million batteries that have been recalled last year, the number of fires, the 1,000 degree F heat, and extremely difficult time extinguishing this type fire. Once it starts, the heat will cause all adjacent cells to explode.

[Lips]

Originally Posted by max52

I have a new job for Empath...Writing warning labels

I use several of these chargers everyday and don't think there sale should be removed or hindered (especially with the chargers sale being prominent on major battery websites) but...


given the consequences of fire and ease at which these chargers can be set to the wrong voltage, a warning is a service to flashaholics... IMHO

Catastrophic damage inside a house can occur with unprotected batteries and everybody around here was a newbie at some point...


.




.

[dom]

A good concern.
Using much more powerful lithiums on my e-bike - i check the cell balance regularly even though the batteries have a BMS.
Alot of people charge their batteries in a fireplace or BBQ with a bucket of sand handy.

Cheers

[nzgunnie]

Does any similar problem exist with the NiMh version of this charger? I think that Li-ions are much more volatile than NiMh, correct? If I have a sealed (welded I think) NiMh battery pack made up of 9x1650 cells to power a mag85, is there any danger of a similar situation with NiMh and the multi current smart charger?

[LuxLuthor]

Originally Posted by nzgunnie

Does any similar problem exist with the NiMh version of this charger? I think that Li-ions are much more volatile than NiMh, correct? If I have a sealed (welded I think) NiMh battery pack made up of 9x1650 cells to power a mag85, is there any danger of a similar situation with NiMh and the multi current smart charger?

Good question!

No, there is not the danger with NiMH (or NiCd) batteries of exploding, fire, toxic Lithium & Hydrogen Fluoride fumes risk....so no problem on his other chargers.

You can even use his Lithium charger as long as you know about the dangers, the cell voltage imbalance that can happen over time, and take proactive steps to protect yourself and home.

[XtreMe_G]

i had a similar concern with using nimh batteries while reading the batteries forum and i did a search. the thread that i found most useful is this. Those liposack in the that lux posted seem to be pretty useful.....if u're too lazy to look here's the link. if there's a gb for these bags, i would most certainly be interested, eventhough i only have protected cells. better safe than sorry

[LuxLuthor]

I just made this post which I think will give a pretty safe use of this Lithium charger in response to someone who lives in a condo.

I can call to see if there is a cheaper price on these Lipo-Sack bags for a possible GB, which normally are about $30.

[Josey]

So it seems we need a charger with independent charging bays. I know Pila makes one for 18650 and smaller cells, but it has only two bays. Anything out there that can be used for larger cells, like AW's C cells?

Or do we just need a smart charger with a slower charging rate?

[Nebula]

Low - Check your local Home Depot or Lowes' for chemical fire extinguishers. They look like a regular fire extinguisher, but are designed specifically for chemical fires. KK

Originally Posted by LowTEC

The next concern would be, what's the proper way to put out this sort of fire when it happens, for one, I know water doesn't work with metal or chemical fire.

[matrixshaman]

The Liposack appears to be made of some type of plastic. I wonder if it is fireproof or if it might give off toxic fumes itself if it became ignited or overheated. It seems to me that a better solution would be to have a metal container. I would use an old metal tool box before using the bag. I've found these often at garage sales and other places cheaply and using one that is say 18" long by about 8" wide by 10" high or so would be handy for this use and the metal would provide some heat distribution if a cell pack did ignite so that it would be unlikely to damage what the tool box was sitting on. You could even put a brick or piece of landscaping concrete like a stepping stone inside to set things on for further protection. Cheap and simple.

[LuxLuthor]

I remember reading on one of the RC forums that someone who used a heavy duty ammo box the 1000+ F Lithium fire heat melted it, and exploded the sides out. The Lipo sack if you look at their website is not flammable...that is the whole point of using it....to contain the flames and explosion.

[Stardust]

Just becareful that you don't turn the metal tool box into a frag granade when the battery do explode while charging.

I think this is why the LipoSack has been designed to use frabics instead of metal for its casing.

[riffraff]

In the RC (Radio-Controlled) hobby, it is standard practice to charge Li-Ion and Li-polymer batteries in a fireproof vessel, and always under supervision. Some people use clay flower pots. I use metal ammo boxes (unsealed, of course). And most multiple cell packs have balancing leads, so the charger can monitor each cell.

Am I correct in my understanding that this charger does not monitor each cell specifically?

[Lips]

Josey So it seems we need a charger with independent charging bays. I know Pila makes one for 18650 and smaller cells, but it has only two bays. Anything out there that can be used for larger cells, like AW's C cells?

Or do we just need a smart charger with a slower charging rate?


Josey

I believe the chargers sold here use .5 amp so that's pretty slow for a pack...




_________________________________________




I did some checking on my FM packs.

(I’m not sure how these battery holders would stand up to a year of taking them apart everyday to charge the batteries…)



The pacs in the lights used a little were all in balance. All cells were close at use and full charge.




The pac in the FM 900L I’ve been using everyday for 20 mins or so for over a month was way out of balance.


After 20 min or so of use:

4.17
3.8
3.9
3.8

After charging to full green with the pack charger:

4.37
4.35
4.35
3.97




I believe I will now check and balance my packs after a week or so of heavy usage…





.

[LuxLuthor]

Originally Posted by riffraff

In the RC (Radio-Controlled) hobby, it is standard practice to charge Li-Ion and Li-polymer batteries in a fireproof vessel, and always under supervision. Some people use clay flower pots. I use metal ammo boxes (unsealed, of course). And most multiple cell packs have balancing leads, so the charger can monitor each cell.

Am I correct in my understanding that this charger does not monitor each cell specifically?

riffraff, you are correct. The problem with all of these flashlight homemade packs for lithium cells is they are just holders for various size Li-Ion cells that are in series and some in S + P. There are no independent taps going to the individual cells like in RC packs.

The "Universal Lithium charger" is then set manually to a S1, S2, S3, or S4 and charges all the cells until it reaches the 4.2V multiple setting chosen.

The only way to balance them is to take out the cells and individually charge them in 1 or 2 bay 400 or 600 mA chargers up to 4.2V each.

[WAVE_PARTICLE]

Thanks, Lux for making these issues of "pack-charging" in series clear. I was initially hoping to be able to pack-charge my batteries with the smart-charger I recently purchased from Alin.....but I'd rather be safe and will only charge one at a time.


WP

[lexina]

thanks for the warning post, LuxLuthor. I had already given up on pack charging my NiMh cells to use in my MagROP and Mag85 when I found that it consistently resulted in unbalanced cells which led to very short run times when the lower charged cells exhausted their charge. For LiIons, I just use a single cell charger.

[bridgman]

Is it fair to say that the concern here is really the concept of series-charging lithium cells, rather than anything specific about the charger itself ?

Are there more expensive chargers which would be considered safe for series charging, ie that can detect the unbalanced cells or at least conclude "I'm not making progress, maybe a cell is low" and shut down ?

[LuxLuthor]

Originally Posted by bridgman

Is it fair to say that the concern here is really the concept of series-charging lithium cells, rather than anything specific about the charger itself ?

Are there more expensive chargers which would be considered safe for series charging, ie that can detect the unbalanced cells or at least conclude "I'm not making progress, maybe a cell is low" and shut down ?

This is really a concern about series charging, and especially with unprotected cells. RC people use packs that have individual Li cells in series, but each cell has it's own lead that has a separate wire connection back to the "Balancer" module of the more sophistocated chargers. The balancer is reading the voltage of each cell real time, and can adjust how much charging voltage is delivered to each lead...or stop the voltage if a cell is ahead of the others.

All of these type of chargers can only see a single voltage reading that is the summary of each cell's voltage added together...so if you have 1 cell that is really high Voltage, and 3 that are really low....it will overcharge the high voltage...because it is assuming all 4 cells have the same "balanced" identical voltage.

It only shuts off when the total voltage of all 4 cells in series reaches the cutoff voltage you set with slider switch. So the effect is that it overcharges the high cell which can make it explode...and the heat then explodes (with fire/toxic smoke) even the lower voltage cells as a cascade effect. The videos show it in a way you will never forget.

One other problem that can cause an explosion is if you have the slider set to "4 cells" and you are only charging 2 or 3.

[gammaray1965]

Hey Luxluther, check out the chargers on the following link:http://www.all-battery.com/index.asp?PageAction=VIEWCATS&Category=177
I believe if you want a good charger the Micro-Controlled Li-Po/Li-ion Balance Charger w/ LCD Display would be a good one.

[LuxLuthor]

Originally Posted by gammaray1965

Hey Luxluther, check out the chargers on the following link:http://www.all-battery.com/index.asp?PageAction=VIEWCATS&Category=177
I believe if you want a good charger the Micro-Controlled Li-Po/Li-ion Balance Charger w/ LCD Display would be a good one.

GammaRay, I actually already have a $175 charger...the thing I am trying to find out is how to setup a safe cradle system that needs to have an individual wire going to each battery. The items you linked assume you have a battery pack that has individual wires connected to each cell in the pack. See the little white connector coming out of this example 4S battery pack on this webpage?



That little connector has wires that go to each cell and gives feedback to the balancer. The question is how to hook up a set of wires like that in a couple of generic DSD type cradles so a balancer could be used.

I made a post on the RC forums to see what they say here.

[Curious_character]

Some time ago I disassembled a Li-Ion computer battery. It had several groups of cells in series, each group having three parallel cells. And inside was an IC whose job it was to charge each parallel group to the correct voltage. I don't recall the IC type, but looked it up at the time and it was made just for that use. There were a number of variations, each for a particular combination of cells.

One way or another, each cell or parallel group of cells has to be charged individually to the correct voltage (4.2 volts), as you've been saying.

c_c

[lexina]

Originally Posted by Curious_character

Some time ago I disassembled a Li-Ion computer battery. It had several groups of cells in series, each group having three parallel cells. And inside was an IC whose job it was to charge each parallel group to the correct voltage. I don't recall the IC type, but looked it up at the time and it was made just for that use. There were a number of variations, each for a particular combination of cells.

One way or another, each cell or parallel group of cells has to be charged individually to the correct voltage (4.2 volts), as you've been saying.

c_c

Recently, I took out my notebook that I had not been using for a while and found that the battery would not charge at all. I was about to dispose of the battery thinking the cells inside were all dead when i decided I might as well tear it apart. To my surprise, although, 2 out of 9 were badly damaged and had leaked, the remaining 7 were still holding a charge of around 3.6-3.7V and were perfectly usable. My point is, if there had been no IC in place, the ones that were chargeable would have over-charged and possibly explode.

[andrewwynn]

it would not take a huge amount of effort to re-wire the fivemega pack that holds your 14500 cells you sent me to install into your M66 light.. The risks of series charging cells is of serious concern and i do mention dozens of times in my posting at CPF that it is quite critical to test your cells occasionally, and preferably every time before charging.. a small modification with drilling out the plastic ends of the FM pack will enable you to measure single cell voltage and you could easily wire in a charging jumper with 5 pins to do a balanced charge which of course would be far better.

On my personal M66 which uses 14650 RAW cells i've tested the cells about every 5th charge and when they are out of the pack i would do a parallel charge to balance them out. In well over a year of use i had no problem whatsoever with unbalanced cells.

Unloaded voltages don't tell us very much (your earlier post).. the full voltages posted above with >4.35V are somewhat scary but an extremely important misdirection is included in the 'scope' of this thread.. (not saying the misdirection is intentional or mean-spirited just not correct).

The exploded cell was NOT FROM A SERIES CHARGED PACK... and NOT from misbalanced cells.. it was from trying to charge a single 3.6V battery to double, triple, or quadruple the voltage... as you can see above from an example of a 4-series charge.. even with a fairly ugly misbalance, all that is going to likely happen is damage to the cells.

Some assumptions that are completely untrue have been made... 'dangerously into fire-starting category'.. this is just completely not true... with chips being sold see here with voltage cut off for maximum as high at 4.65V... i would seriously not be too concerned as long as you occasionally monitor the voltage.

The M66 does drain the cells more completely than usual for hotdrivered lights.. at a nominal 2.875V/cell but that is nowhere remotely near the 'danger zone' for discharge... let's take your exact cell voltage in your example and scale them do shutdown voltage:

The total voltage of the 4 cells in the example: 14.49... it would take a ratio of 80% to get them down to shutdown in an M66.. at 11.55V.. a straight ratio of those values get you to:

3.15V, 2.58V, 3.10V and 2.72V... none of those are in any way shape or form 'dangerously low'.. being above the well established rule of 2.5V/Cell minimum and that's just for damaging the cell not 'causing major problems'.. I have recharged LiON cells damaged down to below 1.5V before.. they had really crappy capacity afterwards but worked for a few cycles.

With the concept of how a hotdriver works only doing 'pack protection'... it will absolutely not run the light if 'a cell' is kaput.. say for example you have a 'dud' cell.. you will likely get virtualy zero volts out of the dud and even if you have 3.6V/cell on 3 other cells.. it will be well below shutdown voltage..

Take some individual cell voltage readings at 'shutdown'... let us know if any are below 2.5V, or even below 3.0V..

The risk is in-fact in the charging which i've told people often... make sure your cells are not below 2.5V and they should be >3.0V each before charging.. i throw out any LiON cells that ever measure no-load less than 3V.. period.

all-batteries and other places have very nice tools for making balanced chargers.. you could easily convert a 4-cell bat. holder into the ultimate charger for balance charging the M66.. but i would recommend modifying the pack.. installing one of those cute little 5-pin jacks and using one of the balance charging devices.. it would not be very difficult to add a wire to the middles of the cells.. the parts in your battery pack are made from brass.. you can solder to them.. just drill tiny holes where needed in the palstic.. pull out the brass. solder wires and pull them through the holes.. you should have room to bring the charge jack up to the rear of the light.. it would be quite a nice improvement to an already superb light.

backing up with personal experience with exactly the charger in question in this thread.. i have done two very very bad things without a serious problem other than destroying the cells.

1) i tried to charge a series set that were drained well below 3V/cell (no load pre-charge)... values maybe were near 2.1V/cell average... one of the cells leaked and melted the plastic on my FM holder they were in while charging.. FM replaced the plastic part even though it was 100% my fault.. the cells that didn't leak charged somewhat but not fully.. i threw out all three cells.

2) I series-charged 3 cells.. with the center cell BACKWARDS.. i can't even imagine how bad that is... or exactly on the 'physics level' what really happened... i think the charger tried to charge the 2 the right way to 3/2 the proper voltage while the backwards one was pulled down to zero volts or even reverse charged.

I didn't notice either of the problems 'til 'hours went by'... if that doesn't show some robustness against 'being a moron'.. (on my part).. i don't know what does.

The critical importance here is not the cell chemistry, but paying attention to detail. I am not personally aware of any non operator error related incident with LION in the flashlight world that was catastrophic.... i've seen lithium primary cell issues, but not LION... and the LIPO explosions were caused on-purpose but doing the same thing this thread exposes.. charging LION or LIPO packs to greatly more than their design voltage can and likely will cause an extreme event often including a loud bang and a burst of fire.

I will point out also from personal experience... i've had nearly the identical event happen when charging a NIMH 16x2/3A cell pack to 21.6V (a quite normal top-off-charge)... the cell wrappers all melted and one cell exploded leaving behind a cloud of black dust in a pile and shot the cell case across the room.. it is not only LION that will misbehave if overcharged... i can only guess that one or two of the cells in my pack died and shorted .. causing a gross overcharge on the remaining cells.. that was using a 'dumb charger' but at a charge rate well within the limits of the spec of the cells!

So.. yes.. be careful charging batteries, but don't be afraid to use them.. even in series and even when LION.. just beware of what you are doing and always have a reasonable idea of the cells voltages before and after charging.

-awr

[andrewwynn]

missed a point.. series operation of RAW LIONs in an unregulated situation (say 2xLION running an 1111 lamp in a 2C light).. is a virtually guarantee to over discharge the cells.. by the time you ever 'see dimming' you have already permanently damaged the weaker of the 2 cells.. guaranteed... a cell that reads 3.0V no-load after such an event was certainly well below 2V during the event. This will not cause any serious problem to the user.. a LION cell can be driven down to zero volts w/o exploding, getting hot or leaking... it's when you try to charge it afterwards where the problems come in to play.

-awr