# Is charging the 18650 a major event in your life?



## Whiskers (Apr 10, 2015)

Charging batteries is the highlight of my evening. The Nitecore D4 Digicharger stays on the floor in the biscuit tin and the weekly discharged 18650s are nearby ready to be locked and loaded and boy do I pay due care. I mean these guys will blow your ears off if they get pissed, right? I tried explaining to my wife how high energy cells need treating but she ended up yawning. In the end I went with the line from Spiderman The Movie _“With great power comes great responsibility”_ and the following educational video: 





How do you charge yours?


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## Amelia (Apr 10, 2015)

Get a life!

Just kidding! 

I'll admit iy gives me a bit of a "rush" to charge a bunch of 18650s at the same time - I'm very aware of the awesome energies involved, and the large aluminum baking tray I put the chargers on when charging seems awefully thin sometimes!


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## markr6 (Apr 10, 2015)

Once I waded thru all the overinflated hype online and youtube videos of people hooking these up to car batteries, I realized it's just another thing in life...like plugging in your toaster or driving a car. You can easily get killed walking your dog.

No big deal. Just buy good cells and chargers. If the deal is too good to be true, it's probably a fake.

I left some cells charging for about 2 days this week; totally forgot in the basement! That $.25 part did it's job to stop charging. Same as the $.25 part somewhere in a plane from keeping it from crashing. Same as the $.25 part that works to inflate your airbag at 60mph.


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## freman (Apr 10, 2015)

My only free plug outlet is under my bed. So it get's charged on my bed, on top of my spare pillow.


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## Nicrod (Apr 10, 2015)

freman said:


> My only free plug outlet is under my bed. So it get's charged on my bed, on top of my spare pillow.



Eeek! This would scare me. Make sure your charger can breath. A lot of charger's breath from the bottom,
so you could be blocking the vents by using a pillow. 

Luckily the new NiteCore chargers have their vents up top! 
Just something that came to mind! I'm sure you know what your doing tho.


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## ven (Apr 10, 2015)

:laughing:

Seriously????

Charging my cells is like opening a can of soup..............yes that exciting for me


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## d123 (Apr 10, 2015)

I treat it with care, about the same care as plugging my phone into its charger.

plug in, turn on, walk away...


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## Keeper Oath (Apr 10, 2015)

Guys as I type, I'm charging three brand new 18650 batteries in my Nightcore D4. Charging time has been 3 hours 45 minutes at the moment. They are 4.04 volts right now. I did leave the house for about two hours. Are you guys telling me I could cause a Black Hole if things go bad and I'm not available to immediately stop charging? Don't do this to me, please.

I am an old farted geek. I used to me a young motorcycle geek forty years ago. Today, I get excited about firing up my new Techno-Toys as I did back then firing up my Harley. Sick? Maybe. A Nerd-Geek? Definitely.


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## ven (Apr 10, 2015)

Hi mr oath,tbh 99.9% of the time you will be fine,however that 0.01% there is always a slight potential risk.

Simply put,its good practice to charge cells whilst your in the vicinity,ideally not left whilst out or over night when one is asleep. Most chargers will be done within 4hrs,even quite deep cycles. So rather than take any potential risk,eliminate them,and stay in the house.

Example-i charge at least 4 cells a day,i dont leave over night or nip out,highly unlikely with a good brand charger and cell,but still i am always around "just in case".

Most chargers do terminate,the nitecore d4 does,as with any electrical item,they should never be relied on fully,so call it better to be safe than sorry.

Just way i am ,my opinion............too add,never had an issue in many years of charging and uses.

Regards ven


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## Amelia (Apr 11, 2015)

Keeper Oath said:


> ...Are you guys telling me I could cause a Black Hole if things go bad and I'm not available to immediately stop charging? Don't do this to me, please....



Black hole? No... Char-broiled house? It's possible. I always babysit my chargers when they're running.


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## Overclocker (Apr 11, 2015)

charging singles no big deal. but when juicing this one up i don't F around...


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## ven (Apr 11, 2015)

pic overclocker .............little OTT for a head torch though !


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## Str8stroke (Apr 11, 2015)

freman said:


> My only free plug outlet is under my bed. So it get's charged on my bed, on top of my spare pillow.



:huh2::sleepy:


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## hiuintahs (Apr 11, 2015)

deleted


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## thedoc007 (Apr 11, 2015)

It is absolutely routine...but I do charge only when I am home. No problem charging overnight, and I don't watch it every minute, but the idea is to be able to respond if there ever was an issue. Just like any other situation that could potentially cause a fire...seems like common sense, even if the odds are quite low. I have a fire extinguisher (amazes me how many people don't) and I charge on a slate surface, which helps keeps the chargers cool.


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## Chay (Apr 11, 2015)

Overclocker said:


> charging singles no big deal. but when juicing this one up i don't F around...



When I'm charging my single 18650s, I babysit them, but that is on the next level!


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## subwoofer (Apr 11, 2015)

A complete non-event, and I do a lot of charging.

Houses have smoke alarms (or should do), and the most I do is make sure the charger is not on or very near to soft furnishings.


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## Grizzman (Apr 11, 2015)

Nope, not at all.


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## RetroTechie (Apr 11, 2015)

hiuintahs said:


> When I see how cheap some of these off the shelf chargers are, I have to wonder exactly how it is designed.


As a counterpoint: a Li-ion charger is basically a regulated voltage source with a current limit. A good/fancy charger may add all sorts of things to that like different charge currents, reverse polarity detection, bringing an over-discharged cell up sloooowly, voltage display, etc, etc. But if you keep things simple, a Li-ion charger is one of the simplest pieces of electronics to make. And _thus_ in practice, even a cheaply produced one can do a decent job.

For comparison a decent NiMH charger must at least watch how a cell's voltage develops _over time_. And perhaps temperatures too (not that watching temps would be a bad thing for a Li-ion charger, but just not _as_ needed as with a NiMH charger). That means some kind of 'intelligence' (read: microcontroller) must be in there. Now those are also cheap in numbers, but still more expensive (and more complex to design with) than a simple voltage regulator. Plastic housing & some metal springs / clamps cost 'nothing'.



> For peace of mind, I ended up designing my own lithium ion chargers......a 12v and a USB powered. But I still only will charge when at home and nearby.


Power to you! :thumbsup: Personally I have better things to do with my life than design YABC (Yet Another Battery Charger).


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## KiwiMark (Apr 11, 2015)

I use 2 hobby chargers that are powered by an old computer PSU.
Both my hobby chargers have a magnetic temperature sensor and I have set the cut-off temperature on my chargers to within 5 degrees of what I've previously seen the cells get to during a normal charge.
I like the fact that a cell starting to get hot will trigger the charger to stop charging it, this seems like a really sensible precaution to me.
I also use two 1 foot x 1 foot ceramic floor tiles to sit my PSU, chargers and batteries on - seems safer than sitting them on my pillow!!!!! 

With my setup I'm pretty happy that a nasty event is unlikely and I'll happily leave the chargers to do their job.


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## Keeper Oath (Apr 11, 2015)

To all you addressed my comments in the #8 post. I used to be into R/C Cars and had top notch equipment. I was always around when I was charging my hot-rod batteries. Why I think my torch batteries aren't as big a deal, I do not know. I think you very much for enlightening me. You may have saved my home as well as my life. My cats say thank you too.


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## Berneck1 (Apr 11, 2015)

I don't go to such lengths. I charge them on my nightstand. I just make sure I'll be home, and take them off the charger as soon as they are done. I will check intermittently to make sure they don't get too hot. I also have some good quality chargers, so I'm not too worried.

I think it's good to be a little cautious and respect the batteries, but like others have said there are dangers in anything. Being that worried about charging these batteries is a little excessive in my opinion. As long as you invest in good quality, you will likely be fine. I do laugh when I see someone paying as high as several hundreds of dollars for a light, and then bargain hunt for batteries.






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## LeafSamurai (Apr 11, 2015)

Berneck1 said:


> I don't go to such lengths. I charge them on my nightstand. I just make sure I'll be home, and take them off the charger as soon as they are done. I will check intermittently to make sure they don't get too hot. I also have some good quality chargers, so I'm not too worried.
> 
> I think it's good to be a little cautious and respect the batteries, but like others have said there are dangers in anything. Being that worried about charging these batteries is a little excessive in my opinion. As long as you invest in good quality, you will likely be fine. I do laugh when I see someone paying as high as several hundreds of dollars for a light, and then bargain hunt for batteries.
> 
> ...



+1 to this post. I only charge them when I'm free and take them off the charger straight after they are done. As always, the golden rule is have good name brand chargers and don't let them charge for too long. I can understand the irony of someone paying big bucks for a light, but then buying cheap low-quality batteries. Some people tend to compensate for buying something expensive by buying something else cheaply, which sadly can be the batteries used for a particular flashlight. Have seen it many times.


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## Whiskers (Apr 12, 2015)

> Get a life!
> 
> Just kidding!
> 
> ...





@Amelia I use the wife's cookie tin. I guess she’ll thank me the day something sets on fire and the only collateral damage is her Oreos. Heh kidding. I take the Oreos out first. I need something to eat while I stare at my charger for four hours!


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## CuriousOne (Apr 12, 2015)

If battery came to me from reliable source, it is fresh, and charge/discharge cycles are managed by me, I know what to expect, so I'm just relaxed, as in case with NiMH. If batteries are low end, come from unknown sources with no info on already used cycles, I prefer to handle them with care, but prefer to give them away, without using at all.


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## ven (Apr 12, 2015)

CuriousOne said:


> If battery came to me from reliable source, it is fresh, and charge/discharge cycles are managed by me, I know what to expect, so I'm just relaxed, as in case with NiMH. If batteries are low end, come from unknown sources with no info on already used cycles, I prefer to handle them with care, but prefer to give them away, without using at all.



Well if i ever receive some NiMH cells via mail from you...................i know i have upset you :laughing:


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## CuriousOne (Apr 12, 2015)

I'm usually giving away 18650s....

A friend of mine works at computer service center, so he often supplies me with dead laptop batteries. Dealed already with about 1000 cells and collected some interesting data:

1. Most depleted and fragile - Sanyo 
2. Low internal resistance, but bad capacity - Panasonic
3. 50% chance - Samsung
4. Deepest recovery gives up to 90% of capacity - Sony
5. Rarely to see at all - LG


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## ven (Apr 12, 2015)

Interesting results there curious one:thumbsup:


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## Whiskers (Apr 12, 2015)

CuriousOne said:


> If batteries are low end, come from unknown sources with no info on already used cycles, I prefer to handle them with care, but prefer to give them away, without using at all.


Haha have some of my spare hand grenades. I've lost the pins!


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## Whiskers (Apr 12, 2015)

*Wonders if it can be wired up to wife's _personal massager_*


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## ShineOnYouCrazyDiamond (Apr 12, 2015)

I was a bit relieved reading through this thread. I thought it may turn into a doom and gloom thread on people charging their cells in cement bunkers wearing bomb gear. 

I only single charge cells when I am home and can check on them and pull them off within a reasonable time frame after completion. But I also make sure I only buy reliable brand cells and higher end chargers that have proper CC/CV charge curves and proper termination.

But I think about all the power tools I have that use LiIon battery packs and when I charge those I think even less about it. I'll pop those on the chargers and sometimes leave them overnight - who knows the quality of some of the dedicated chargers that come with these tools.


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## Berneck1 (Apr 12, 2015)

ven said:


> Well if i ever receive some NiMH cells via mail from you...................i know i have upset you :laughing:



Lol I was thinking the same thing! 


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## radiopej (Apr 12, 2015)

I only charge mine while I'm at home, but that includes leaving them overnight while I sleep. 

The charger cuts of at 4.2 volts. It's the same battery chemistry in my phone. So far I trust the batteries I have as my 18650s are from reliable sources and are protected. My 2 16340s are from a fairly reliable seller - the protected one is KeepPower, the unprotected one is from the same seller but doesn't have a name. They seem to work fine. 

I have a Trustfire 10440 coming in soon. That one I think I'll only charge while I'm in the room and awake. I wouldn't trust crappy chargers at all. Buying a reliable charger saves a lot of worry.


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## Kurt_Woloch (Apr 12, 2015)

I don't have any "free" LiIon cells. The only lithium based batteries are those in my digital camera, my phone and my laptop, and those can only be charged in the device itself. And I trust those devices knowing how to properly charge their battery. In the case of the phone and digital camera, they are plugged into USB ports, so they have all the charging electronics in the device. In case of the laptop, I don't know if there's part of the charging electronics in the pack itself or if the laptop does all this. I think the battery pack has got some kind of memory where it stores some information like how much total capacity it still has, and maybe it also provides some part of the charging logic. Basically, I don't think it's necessary being around when those devices charge although I usually am since the USB ports are only active as long as I work on the given PC, and the laptop usually gets charged while I work. There are exceptions where I may leave one of the devices at my workplace and go for lunch, or go to sleep while they continue charging. I don't think much can happen this way.

As for other batteries, I only use NiMh and lead-acid batteries. I don't think these pose a danger when they get charged overnight when I'm usually at home, but sleeping. But the NiMh charger terminates charge on full batteries (although it sometimes misses termination when 3 or 4 cells are charged at once), and I only charge the lead-acids overnight after making sure they've still got a long way to go until full (or after forgetting to put them off before going to bed).

Still, there is a major event called "Recharging unused batteries" which I've placed in my calendar a few times a year. This event takes a bit over an hour in total, and over the course of it, I'll check all rechargeable cells and also the used primaries, charge any batteries that need charging and discard those which have reached 0 volts and can't be recharged anymore, or have leaked.

Other than that, I do feel some kind of happiness each time I put a set of NiMh's on the charger because I know I'm able to use them again without having to buy new batteries. It's some kind of victory over today's throwaway society. But to be honest, if I had to do more safety precautions with the NiMh's, such as only charging them when at home or in the same room, it'd probably not be worth it, and I'd use alkalines instead, as cheap as they are now.


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## KiwiMark (Apr 22, 2015)

ShineOnYouCrazyDiamond said:


> I only single charge cells when I am home and can check on them and pull them off within a reasonable time frame after completion.



I use chargers I trust.
I am happy to leave the batteries on there all night - I trust the chargers to shut off when finished.
I'd happily go out while the batteries are charging - I trust the chargers' safety features.
Having the thermal sensor sitting against the battery does help a lot to ease my mind and I really do like not having to worry about something bad happening.


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## magellan (Apr 22, 2015)

LOL.

Actually I'm trying to keep it from becoming a major event by observing safe lithium ion battery use and charging procedures.


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## markr6 (Apr 22, 2015)

I find it strange that people trust a cell phone or laptop charger 100% without thinking about it. But a $60 Xtar charger and Panasonic cell can suddenly become an issue? Not for me. I'm pretty sure they're more than just two shady guys building these in a garage somewhere. Lots of hearsay and anecdotal evidence causing people to stick with NiMH exclusively. Too bad, but that's how it goes.


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## Overclocker (Apr 22, 2015)

markr6 said:


> I find it strange that people trust a cell phone or laptop charger 100% without thinking about it. But a $60 Xtar charger and Panasonic cell can suddenly become an issue? Not for me. I'm pretty sure they're more than just two shady guys building these in a garage somewhere. Lots of hearsay and anecdotal evidence causing people to stick with NiMH exclusively. Too bad, but that's how it goes.




phones and laptops have batt management systems. notice the batts have more than 2 terminals? for temp monitoring, and a bunch of other stuff.

safer


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## Berneck1 (Apr 22, 2015)

markr6 said:


> I find it strange that people trust a cell phone or laptop charger 100% without thinking about it. But a $60 Xtar charger and Panasonic cell can suddenly become an issue? Not for me. I'm pretty sure they're more than just two shady guys building these in a garage somewhere. Lots of hearsay and anecdotal evidence causing people to stick with NiMH exclusively. Too bad, but that's how it goes.



I agree. I think there is a degree of overthinking going on. However, given the amount of people in here who are modding things or seeking that super-cheap high capacity battery, have reason to be cautious. If you're buying high quality well-known names you should be fine. 

You would serve yourself better getting a smoke detector, fire extinguisher and CO2 detector! ;-). It still amazes me how many stories I read of homes without these things....


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## HKJ (Apr 22, 2015)

Overclocker said:


> phones and laptops have batt management systems. notice the batts have more than 2 terminals? for temp monitoring, and a bunch of other stuff.



Laptop battery packs has a BMS chip inside, phone batteries has a protection chip (Same chip as protected cells) and a temperature sensor (The extra terminal). The software in the laptop and phone will usual also do some battery management.

You hand drill and other tools does not have any BMS, only protection and temperature sensor.


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## markr6 (Apr 22, 2015)

Overclocker said:


> phones and laptops have batt management systems. notice the batts have more than 2 terminals? for temp monitoring, and a bunch of other stuff.
> 
> safer



So the Xtar has nothing? It's just dangerously pumping 1A into cells for the heck of it?


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## magellan (Apr 22, 2015)

markr6 said:


> So the Xtar has nothing? It's just dangerously pumping 1A into cells for the heck of it?



I guess in that case BMS stands for Battery Mismanagement System. ;-(

Yes, simple dumb chargers don't do much, which is why I don't use them anymore. But smart chargers like Xtar do more than the above as people here like HKJ who know lot more than I will tell you. A more advanced charger will have temperature sensors with integrated fan cooling, thermal cutoff, correct battery charging termination algorithms, and possibly more. I'm sure there's more but I will let the more savvy folks chime in here if they want on the rest.

Battery chemistries also differ in the degree to which they can tolerate abuse. NiMH batteries rarely catch fire or explode no matter how much abused, but it does happen. But mostly it's the lithium ion batteries that we have to be concerned with. Even so, there are big differences in the main lithium ion types. You have to be careful with LiCoO2, but LiMnO2 and LiFePO4 are much more tolerant, to the extent that they are typically offered without protective circuits.

By contrast, NiMH and NiCd batteries are less sensitive to overcharging with NiCd being the best which is why they're often used in solar lighting applications since as long as the sun is shining the battery is getting charged. Although NiMH probably aren't going to explode if overcharged, it will shorten lifespan.

A few more comments on laptop and phone batteries. As previously noted, those batteries have extra terminals which are part of the BMS, which allows more sophisticated control and sensing during charging, including calculations for SOC (state of charge). Unfortunately there's no direct empirical way to sense a battery's state of charge so various assumptions have to be made. What happens is that over time, as the battery ages, the SOC algorithm gets out of sync with the actual battery. 

For example, the SOC algorithm is desgned for an average battery. But batteries differ in quality and age differently. If a battery is better than the average then over time the BMS will indicate less capacity than it actually has. If a battery is worse than average then over time it will indicate it has more capacity than it actually has.

Those are the basics. That's all I know. I'm just a martial arts and tai chi instructor.  I'll let the more knowledgeable folks here correct anything I've said if necessary and chime in on the rest if they want.


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## markr6 (Apr 22, 2015)

Speaking of life events


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## Amelia (Apr 22, 2015)

magellan said:


> ...Even so, there are big differences in the main lithium ion types. You have to be careful with LiCoO2, but LiMnO2 and LiFePO4 are much more tolerant, to the extent that they are typically offered without protective circuits...



I don't believe this part of your post is entirely correct. From my reading, the two "alternative chemistry" LiIon battery types are not inherently all that much safer than LiCo. They can both still fail catastrophically if abused. My understanding (and I could be wrong, PLEASE correct me if I am!) is that LiMnO2 chemistry is more tolerant of HIGH DISCHARGE RATE uses, and LiFePO4 is better able to withstand physical abuse than the other 2 types. I haven't read anywhere that either type is anywhere close to NiMH in terms of safety.

Also, protection circuits are more for prevention of battery undercharge/overcharge cell damage than they are "safety" protection - though it does overlap a bit on the "overcharge" side of things. I have LiMnO2 protected batteries, and my reading has lead me to the conclusion that it is just as harmful to the battery to undercharge or overcharge them as it is for LiCo.


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## magellan (Apr 22, 2015)

Hi Amelia,

Actually they are so considered (and the experts here can feel free to correct me correcting you as I don't claim to be an expert), especially in the case of LiFePO4, which is considered quite tolerant of abuse. See response #2 by thedoc007 in the thread I started here recently:

http://www.candlepowerforums.com/vb...8-I-screwed-up-Am-I-doing-something-dangerous

But you're absolutely right in that there is no super safe lithium ion chemistry (compared to NiMH anyway) and all types deserve respect and should be treated accordingly.

In my case I really baby all my cells to an almost ridiculous extent. I don't over and under discharge, run them hard, expose them to extremes of temperature, store them with a full charge or too low a charge, and I make sure they get a rest after charging. If I drop one (which doesn't happen very often) I number it and make a record of it in my notes. 

As far as the rest period goes, I've only recently learned of this. A disproportionate number of the accidents in the vaping community have been traced to charging a battery, especially exposing it to a fast charge, and then putting it immediately into service in a high drain application such as a so-called custom, sub-ohm hotwire mech mod. But that's not something I do. So I feel I don't have to worry as much about the non LiCoO2 ones. They still get the same considerate treatment as the LiCoO2 ones because it's just easier to maintain my "battery discipline" if all types get the same treatment. If I treat one type different I'm worried I'll get sloppy with the others.


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## magellan (Apr 24, 2015)

Amelia said:


> I don't believe this part of your post is entirely correct. From my reading, the two "alternative chemistry" LiIon battery types are not inherently all that much safer than LiCo. They can both still fail catastrophically if abused. My understanding (and I could be wrong, PLEASE correct me if I am!) is that LiMnO2 chemistry is more tolerant of HIGH DISCHARGE RATE uses, and LiFePO4 is better able to withstand physical abuse than the other 2 types. I haven't read anywhere that either type is anywhere close to NiMH in terms of safety.
> 
> Also, protection circuits are more for prevention of battery undercharge/overcharge cell damage than they are "safety" protection - though it does overlap a bit on the "overcharge" side of things. I have LiMnO2 protected batteries, and my reading has lead me to the conclusion that it is just as harmful to the battery to undercharge or overcharge them as it is for LiCo.



There's one more thing I forgot to say.

There's also the fact that uninformed beginners are different from experienced or expert users. Your view is really exactly what a beginner should have. Until neophytes learn the differences, they should treat all lithium batteries the same. As I said, I still pretty much do. But more expert users understand the differences, make informed choices, know the risks and what not to do, and just don't worry as much that their flashlight is going to explode in their hand, as you can see from the posts here. As has been observed here many times, using a lithium ion battery is a lot safer than getting in a car. In fact there are probably a lot of things people do throughout the day that are riskier than using lithium ion batteries.


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## Amelia (Apr 24, 2015)

magellan said:


> There's one more thing I forgot to say.
> 
> There's also the fact that uninformed beginners are different from experienced or expert users. Your view is really exactly what a beginner should have. Until neophytes learn the differences, they should treat all lithium batteries the same. As I said, I still pretty much do. But more expert users understand the differences, make informed choices, know the risks and what not to do, and just don't worry as much that their flashlight is going to explode in their hand, as you can see from the posts here. As has been observed here many times, using a lithium ion battery is a lot safer than getting in a car. In fact there are probably a lot of things people do throughout the day that are riskier than using lithium ion batteries.



Thank you. I think you covered everything quite well in those last 2 posts, probably better than my attempt.
Essentially, "safe" and "Lithium Ion Battery" don't really go together - but neither do "safe" and many other things we do in our daily lives either. It's less about achieving true safety as it is about well informed risk management.


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## magellan (Apr 24, 2015)

Amelia said:


> Thank you. I think you covered everything quite well in those last 2 posts, probably better than my attempt.
> Essentially, "safe" and "Lithium Ion Battery" don't really go together - but neither do "safe" and many other things we do in our daily lives either. It's less about achieving true safety as it is about well informed risk management.



Thanks, and I agree completely.

A few more perhaps random thoughts, which are probably more in the spirit of your original post. 

The problem is, as you discussed, there are no super safe, foolproof cells. That's no problem for the informed "power user." The problem is, as has been mentioned on this forum many times, there are a lot of crappy and fake batteries out there being sold to naive consumers who have no idea what they're getting. They think they're getting a bargain, but what they're often getting is recycled and relabeled laptop batteries, batteries that failed quality control, imitations or fakes of respected battery brands, and so on. I learned on this DB that there are whole facilities in China that do nothing but rewrap batteries which they buy cheap by the ton because the rewards are enormous. Who knows what you're getting if you get one of these.

The remedy of course is to stick with known quality brands and suppliers, but again that also implies a more savvy user.

It reminds me of something a friend said one time. We were in an electrical storm, and I suggested we walk to a nearby friend's place. It was only a short distance, but he didn't want to go because of the lightning. I pointed out the odds were still a million to one against getting struck by lightning. He said, "Yeah, it might be a million to one, but if it happens you're still 100% dead." 

So this is why we're careful with lithium ion batteries. The odds are nothing will happen, but if it does the results could be dramatic. So being safe is really just common sense.


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## Agamemnon Jones (Apr 24, 2015)

"Charging my cells is like opening a can of soup..............yes that exciting for me"

...what kind of soup?


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## magellan (Apr 25, 2015)

Something spicey and with a little kick to it I hope.


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## AA#5 (Apr 25, 2015)

I've never been comfortable charging them while I'm not home or asleep. And I check on them a few times during charging. They've always been only slightly warm.


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## ven (Apr 25, 2015)

Agamemnon Jones said:


> "Charging my cells is like opening a can of soup..............yes that exciting for me"
> 
> ...what kind of soup?




A chicken soup without the chicken :laughing:


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## KiwiMark (Apr 25, 2015)

magellan said:


> Yes, simple dumb chargers don't do much, which is why I don't use them anymore. But smart chargers like Xtar do more than the above as people here like HKJ who know lot more than I will tell you. A more advanced charger will have temperature sensors with integrated fan cooling, thermal cutoff, correct battery charging termination algorithms, and possibly more. I'm sure there's more but I will let the more savvy folks chime in here if they want on the rest.



The best way to work with simple dumb chargers that you don't trust is to replace them with good chargers that you can trust.
Li-ion cells are just better than NiMH in many ways, especially the 18650 cells with their awesome energy density when you get good quality cells like Panasonic 3400mAh.
The A123 cells are also really great for many applications with their ability to deliver high currents reasonably safely.
Li-Ion batteries can start cars and power tools and even provide convenient sized flashlights with great output combined with a decent run time.

Do you guys remember what jump start systems used to look like a few years ago? Look what you can get now: https://www.youtube.com/watch?v=bf7u8rQTt94
Yep, that is thanks to Li-ion batteries.

My view is this:
Li-ion batteries are really good, but get a decent charger that you can trust to not start a fire or whatever.


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## Gauss163 (Apr 25, 2015)

magellan said:


> Unfortunately there's no direct empirical way to sense a battery's state of charge so various assumptions have to be made. What happens is that over time, as the battery ages, the SOC algorithm gets out of sync with the actual battery. For example, the SOC algorithm is desgned for an average battery. But batteries differ in quality and age differently. If a battery is better than the average then over time the BMS will indicate less capacity than it actually has. If a battery is worse than average then over time it will indicate it has more capacity than it actually has.



That applies only to very old or very cheap BMS. Current top-tier BMS do an excellent job accurately tracking SOC over the entire lifespan of the pack, e.g. look up TI's impedance-tracking algorithm.


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## magellan (Apr 25, 2015)

Hi Gauss163,

Thanks, will do that. My info is probably several years out of date. Interestingly I've heard of research on a very accurate SOC method using amazingly enough quantum electronic phenomena. No idea if it'll ever pan out but it's an example of how far they're going to try to come up with something.

Will check out TI's method shortly.

Ah, just found this article from Texas Instruments:

http://www.ti.com/lit/an/slua450/slua450.pdf

Very impressive. I'm working thru the article although some of it is over my head. I may have some comments after I've finished digesting the article.


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## magellan (Apr 25, 2015)

KiwiMark said,

<<Do you guys remember what jump start systems used to look like a few years ago? Look what you can get now: https://www.youtube.com/watch?v=bf7u8rQTt94Yep, that is thanks to Li-ion batteries.>>

Jesus H. Christ.


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## magellan (Apr 25, 2015)

Hi KiwiMark,

Thanks for the comments. I did indeed replace my dumb chargers with smart chargers about two years ago. Now I have a growing collection of smart chargers of different sizes, configurations, battery chemistries, and makes and models at this point. It's almost become a side hobby to the flashlights and batteries one. 

I see you're in Waikato, N.Z. I was there on a vacation from the U.S. just over a month ago. Small world.


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## CuriousOne (Apr 28, 2015)

Anyone taken apart that NOCO thing? it uses 18650s or LiPo's ?


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## recDNA (Apr 28, 2015)

I have a good xtar charger but I absolutely hate recharging. I like things that are set it and forget it and go back later. I have learned here you just cannot do that when recharging li ions. I find it a royal pita. I hope the tech advances someday to the point it is safe to put batteries in a charger and go to bed.


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## recDNA (Apr 28, 2015)

KiwiMark said:


> The best way to work with simple dumb chargers that you don't trust is to replace them with good chargers that you can trust.
> Li-ion cells are just better than NiMH in many ways, especially the 18650 cells with their awesome energy density when you get good quality cells like Panasonic 3400mAh.
> The A123 cells are also really great for many applications with their ability to deliver high currents reasonably safely.
> Li-Ion batteries can start cars and power tools and even provide convenient sized flashlights with great output combined with a decent run time.
> ...


I don't know of any such charger. The battery could be the problem but the fire still might start.


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## magellan (Apr 29, 2015)

Gauss163 said:


> That applies only to very old or very cheap BMS. Current top-tier BMS do an excellent job accurately tracking SOC over the entire lifespan of the pack, e.g. look up TI's impedance-tracking algorithm.



Hi Gauss123,

I worked my way thru that paper. I did have one question, which I hope won't be too far off topic. They mention doing coulomb counting as part of the tracking and updating process. I was under the impression coulomb counting doesn't work well for spinel structure batteries which have a 3-dimensional lattice like lithium manganese oxide? Maybe they just use it for the other lithium ion chemistries? 

Anyway, great recommendation and very informative, thanks.


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## KiwiMark (May 7, 2015)

recDNA said:


> I don't know of any such charger. The battery could be the problem but the fire still might start.



well maybe I guess, but I would think that most battery faults would not cause a fire if the charger cut off as soon as the battery started to approach the 'too hot to touch' point. When fully charged my batteries can be warm but a bit above the temperature that they typically get to is the temperature I have set the charger to cut off at.
I guess something could go terribly wrong and the battery could get warm and then continue getting hotter despite the charger having cut off, but I'd suspect that the battery could just as easily go rogue when not being charged if it is that faulty (like internal short problem or whatever).

I do take the precaution of placing the battery on a non-flammable surface and attaching the temperature probe, to my mind I'm being careful enough and there is no need to be over the top paranoid here. I also spend more on quality batteries rather than buy the poor performing junk that claims super high capacity for half the price.


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## gianetics (May 7, 2015)

Overclocker said:


> charging singles no big deal. but when juicing this one up i don't F around...




Jesus h Christ. where the heck is the Delorean. how many 18650's does it take to power a flux capacitor?


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## Overclocker (May 8, 2015)

gianetics said:


> Jesus h Christ. where the heck is the Delorean. how many 18650's does it take to power a flux capacitor?



apparently 96 aren't enough. i'm adding 96 more...


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## Arizona_Mike (May 8, 2015)

My intellechargers turn off but lithium cells are floatable at the charging cutoff voltage or lower. They are not little sticks of dynamite. I buy only reputable cells and try to charge at of below 0.3C to prolong life. Hell, if it's over night I'll set my charger for 300 mA which is about .12 for my Japanese and Korean 2600mA cells and even lower for the fancy Panasonics.

The only time I drag my charger out to the concrete slab in the garage is when I charge the "fire" brands that some toys come with.

Mike


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## markr6 (May 8, 2015)

gianetics said:


> Jesus h Christ. where the heck is the Delorean. how many 18650's does it take to power a flux capacitor?



_WHAT THE HELL IS A GIGAWATT?_


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## magellan (May 8, 2015)

Arizona_Mike said:


> My intellechargers turn off but lithium cells are floatable at the charging cutoff voltage or lower. They are not little sticks of dynamite. I buy only reputable cells and try to charge at of below 0.3C to prolong life. Hell, if it's over night I'll set my charger for 300 mA which is about .12 for my Japanese and Korean 2600mA cells and even lower for the fancy Panasonics.
> 
> The only time I drag my charger out to the concrete slab in the garage is when I charger the "fire" brands that some toys come with.
> 
> Mike



Is the termination voltage on the lithium ions accurate enough on an intelligent charger so that you don't have to worry about overcharging as with the sometimes difficult dV/dt method with NiMH?


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## Arizona_Mike (May 8, 2015)

Like I said, these cells are floatable at the charding voltage but when slow charging with my intellechargers my currents in the final couple hours are in the mid 40mA range. Say 45mA at 4.2v and you are looking at less than 1/5 watt. Even at 300mA you are looking 1.3 watts dissipation even if something was very wrong with the cell and it was all going to heat not charge. Every destructive test video I've ever seen uses some pretty significant over-voltages.

Endpoint detection on NiMH is much more complex.

Mike


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## magellan (May 8, 2015)

Okay, thanks. I guess I think of float and topping off charges as being more typical of lead acid batteries, although I suppose the principle applies to most chemistries.

Thanks for the detailed explanation.


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## Nicrod (May 9, 2015)

Is charging and managing cells a major event for me...just a little. 

9-RCR123's
6-ICR18650's
5-IMR 18350's
4-IMR 16340's
4-14250's (CR2's) 
3-IMR 18650's
2-17670's
2-14500's


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## KiwiMark (May 9, 2015)

Nicrod said:


> Is charging and managing cells a major event for me...just a little.



It would appear that you are single handedly trying to pay AW's kids through college! :laughing:


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## Nicrod (May 9, 2015)

KiwiMark said:


> It would appear that you are single handedly trying to pay AW's kids through college! :laughing:





I prolly am! 
And these are just my AW brand cells ! 

What can I say, I LOVE AW cells. They are my Favorites, and 
they make a darn Good product. I wouldn't trust anyone else


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## magellan (May 10, 2015)

Wow. Impressive collection.


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## G. Scott H. (May 11, 2015)

gianetics said:


> Jesus h Christ. where the heck is the Delorean. how many 18650's does it take to power a flux capacitor?



Thanks. That gave me a good chuckle. :twothumbs

Incidentally, here's some video of a similar Li-ion pack failing: 

 :laughing:


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## magellan (May 11, 2015)

Isn't that the 100 megaton Tsar bomb?


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## G. Scott H. (May 11, 2015)

It is the Tsar, but I believe it was only ~50 megatons.


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## magellan (May 11, 2015)

Yes. Come to think of it, I seem to remember it was rated at 60 megatons.


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## recDNA (May 20, 2015)

magellan said:


> Yes. Come to think of it, I seem to remember it was rated at 60 megatons.


How many watts is that?


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## MrJino (May 20, 2015)

Oh you guys are scaring me...

Getting my first 18650 and charger (supplied by darksucks with the ready made journey), and do I have to watch it carefully towards the end?

I assumed chargers automatically shut off after completion...
I am planning to charge the spare via usb solar panel...


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## ChrisGarrett (May 20, 2015)

MrJino said:


> Oh you guys are scaring me...
> 
> Getting my first 18650 and charger (supplied by darksucks with the ready made journey), and do I have to watch it carefully towards the end?
> 
> ...



What charger and what cells will you be using?

It's pretty much 'a walk in the park' if you buy quality stuff, but I can understand your apprehension in the beginning.

Chris


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## MrJino (May 20, 2015)

ChrisGarrett said:


> What charger and what cells will you be using?
> 
> It's pretty much 'a walk in the park' if you buy quality stuff, but I can understand your apprehension in the beginning.
> 
> Chris



For the 18650, it's the one that comes with the ready made journey.

AW 2900mAh battery and the XTAR-MP1S charger


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## ChrisGarrett (May 21, 2015)

MrJino said:


> For the 18650, it's the one that comes with the ready made journey.
> 
> AW 2900mAh battery and the XTAR-MP1S charger



I have an Xtar MP1S charger and it under-charges my cells--4.15v-4.16v, so I consider it faulty, but it's not 'unsafe.'

Chris


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## HKJ (May 21, 2015)

ChrisGarrett said:


> I have an Xtar MP1S charger and it under-charges my cells--4.15v-4.16v, so I consider it faulty, but it's not 'unsafe.'



I would give that top rating, it sound like it charges with *4.20* volt as a LiIon charger is supposed to do.
Even if it only charged with 4.15 volt it would still be within specifications for most LiIon cells.


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## thedoc007 (May 21, 2015)

ChrisGarrett said:


> I have an Xtar MP1S charger and it under-charges my cells--4.15v-4.16v, so I consider it faulty, but it's not 'unsafe.'



You consider it faulty because it doesn't overcharge? If you see 4.2 volts after the charge is complete, you are at least slightly overcharging, since voltage ALWAYS drops at least a little bit when you stop charging. Your charger is doing the job properly...and is within specification...and will provide slightly longer cell life compared to a charger that gives you a reading of 4.2 volts after charge. Nothing wrong with that!


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## RetroTechie (May 21, 2015)

MrJino said:


> Oh you guys are scaring me...


Never mind the Tsar bomb references, people are exaggerating sometimes. How about a bit of math for perspective?

Let's take our beloved 3400 mAh, 3.6V nominal Panasonic 18650. That's ~12 Wh energy contents.
12 Wh = 12 J/s * 3600s = ~43 kJ or ~10 kcal. The latter being the same unit that the average person needs around 2000-2500 of per day.
Read: the energy contents of one of the very best, fully charged 18650 is in the order of what you get when burning *just over 1 gram of fat*, or 2-3 grams of protein/carbohydrates.

That's not the whole story: Li-ions contain an electrolyte, usually an organic compound (read: potentially flammable). And often a carbon compound as an electrode material. I've got some safety datasheet here, which puts both between 10-20% of a cell's weight (which is under 50g total for our beloved Panasonic cell). The rest is lithium/other metal *salts* (not flammable), steel can, button top, plastic wrapper etc.

For argument's sake, let's say that carbon electrode material is just as flammable as the electrolyte. Both together, that's still just 10-20g of flammable material. In the order of what's inside a cigarette lighter.

That material needs oxygen to burn, so it can't burn until it gets out of the cell. If a cell leaks, there's no pressure behind it and very little material would leak. If a cell vents, that's because materials inside are heated _beforehand_ by electrical energy, which is quite limited as shown above. So if for example you drive a nail through the cell, what's needed to heat its contents to the point of venting, comes from that relatively small ~43 kJ electrical charge. In the case of over-charging, some of it could come from the charger (but charge current will likely be low by the time a cell is fully charged). The larger portion of energy released if a cell's contents catches fire, is only released _after_ the cell is heated to the point where it vents, and the flammable vapors mix with air. That is, *IF* those vapors catch fire - by no means a given! If not, the only energy released is the electric charge.

That's of course if the cell's built-in safety features fail (of which there are multiple ones in a good Li-ion). And -in the case of a protected cell- the protection circuit as well. In *any* off: smaller type (14500, 16340 etc), a not-fully charged, an old cell, a LiFePO4 cell, ...Fire junk with 1/5th the stated capacity, you've got much less electrical energy available to self-heat the cell.

Of course you have things like a 6-cell light, where 5 cells can dump their charge in the 1 unlucky cell that was empty. And in the case of flashlights, vent gasses may have nowhere to go, turning that metal tube into a small pipebomb of sorts. But charging is generally considered the most 'dangerous' step, and I'm not doing that with the cells inside a metal tube. Once they're in a flashlight, I'm taking energy _out_ of the cells, not putting more energy _in_ them.

This morning got a small cut using a kitchen knife. Must have happened _dozens_ of times over the course of my life. Same thing with sharp edges on cardboard boxes, blister packaging,  etc. Li-ions otoh: have been using them in one form or another since they appeared in consumer devices. Never, *ever* got hurt using them, not even the slightest, in any way whatsoever.

So yes, charging Li-ions outside lights, on a table or kitchen top with no flammable stuff like curtains etc near it, seems like common sense. Same with removing cells from charger when full. But other than that, let's not get carried away...



Arizona_Mike said:


> Every destructive test video I've ever seen uses some pretty significant over-voltages.


Yep, there's quite a few YouTube vids around of venting & burning cells. Notice how virtually without exception, such videos also involve a car battery, hooking up to mains AC, pumping the charge of a full pack into 1 cell, etc. Aka external power input.

More realistic tests _sometimes_ manage a "cell vented" result, but hardly ever make it to "vent with flame". Note that the "with flame" part is rather important for how much damage is done in real-life failures (room filled with nasty fumes vs. _potentially_ your house on fire).


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## SVT-ROY (May 21, 2015)

I'm still new to the game using an Xtar panzer. I only have olight 2600 and 3400 cells in 18650. Every few weeks I'll top them off. I'm not allowed to mention lights and batteries at home anymore. The woman is tired of it haha. My main buddy at work is even tired of it, I told him whatever ppl care about this stuff. When he asked who I said with a proud stern voice, my Internet buddies..ha


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## ChrisGarrett (May 21, 2015)

HKJ said:


> I would give that top rating, it sound like it charges with *4.20* volt as a LiIon charger is supposed to do.
> Even if it only charged with 4.15 volt it would still be within specifications for most LiIon cells.





thedoc007 said:


> You consider it faulty because it doesn't overcharge? If you see 4.2 volts after the charge is complete, you are at least slightly overcharging, since voltage ALWAYS drops at least a little bit when you stop charging. Your charger is doing the job properly...and is within specification...and will provide slightly longer cell life compared to a charger that gives you a reading of 4.2 volts after charge. Nothing wrong with that!



Well maybe "faulty" was a poor choice of words.

I'll say that it charges substantially less than my WP2 II and my VP2, which as HKJ has pointed out, fit with Xtar's M.O. of slightly undercharging cells--not a bad thing for li-ions.

In this regard, I think that it's at the lower end of the 'acceptable' scale, especially for somebody that doesn't, as a rule, undercharge his cells in the interest of longevity.

I have the Xtar MC1+ and the XP1 USB chargers coming in the mail today, or tomorrow and I'll see how they perform.

Chris


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## HKJ (May 21, 2015)

ChrisGarrett said:


> I have the Xtar MC1+ and the XP1 USB chargers coming in the mail today, or tomorrow and I'll see how they perform.



Generally this charge voltage is not related to the actual charge model, but varies with component tolerances, i.e. if you buy a pile of one model you may get charge voltages from 4.15 to 4.25 volt, with most somewhere in the middle.


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## magellan (May 21, 2015)

recDNA said:


> How many watts is that?



Yeah, anyone know the conversion?


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## magellan (May 21, 2015)

<<Read: the energy contents of one of the very best, fully charged 18650 is in the order of what you get when burning just over 1 gram of fat, or 2-3 grams of protein/carbohydrates.>>


As Mr. Spock would say, fascinating.


Ha-ha. I had no idea I was carrying the equivalent of thousands of dollars of batteries around my waist.


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## Gauss163 (May 23, 2015)

You also need to account for _combustion energy_, for example, from Barsukov & Qian, p. 94
----
However, one of the side effects of organic electrolytes is that when the temperature exceeds a certain limit depending on battery chemistry, the reaction between the active material and electrolyte releases heat and becomes self-supporting (thermal runaway), which can cause a fire, explosion, or venting of electrolyte. Just how destructive can such an event be? It depends on the amount of energy released. Let's compare the energy of an 18650 Li-ion battery with that of a well-known destructive device, say, a hand grenade filled with TNT. TNT releases energy of 4.1 kJ/g. A Li-ion battery stores 0.250 Wh/g, which corresponds to 0.93 kJ. This is about one-quarter of the TNT energy. But — and this is a big difference with traditional batteries that have a water-based electrolyte — a Li-ion battery has additional energy in its organic electrolyte! In case of combustion, it will also burn. So will polymer separators. As reported in a safety analysis [1], the energy released by the burning of up to 10 g of electrolyte and 1.6-g separators contained in an 18650 cell is 280 kJ. Given the cell weight of 40 g, we get 280/40 = 7 kJ/g of combustion energy. So, taken together, the electric and material burning energy per gram of Li-ion battery is around 8 kJ/g, close to twice that of TNT! Comparing an 18650 cell with a typical hand grenade (U.S. M67, with 180 g of explosive), it takes only five 18650 cells to exceed the hand grenade's energy! A typical notebook battery pack (3 serial/2 parallel, 3s2p) has six cells, so it has _more combustion energy than a hand grenade._ I trust this will make you pause a moment.

Fortunately, battery combustion is not nearly as fast as that of explosives ...


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## HKJ (May 24, 2015)

Gauss163 said:


> You also need to account for _combustion energy_, for example, from Barsukov & Qian, p. 94



*Scaremongering*, try calculating the equivalent number of hand grenades for a filled gas tank on your car (Gasoline as nearly 10 times the energy density of TNT).


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## RetroTechie (May 24, 2015)

Gauss163 said:


> A typical notebook battery pack (3 serial/2 parallel, 3s2p) has six cells, so it has _more combustion energy than a hand grenade._


Possibly. And probably the same goes for a pound of butter. Your point being? :thinking:



HKJ said:


> *Scaremongering*, try calculating the equivalent number of hand grenades for a filled gas tank on your car (Gasoline as nearly 10 times the energy density of TNT).


+1.

The destructive effect of a hand grenade (or TNT) comes from the *extremely* short time in which the energy is released. And shockwave that goes with it (not to mention metal fragments :duck. *NOT* so much from the amount of energy (aaaand... if I understand correctly, energy released from explosive _detonation_ is not the same as when the material would be burned).

The thermal runaway is just a matter of some decomposition process accelerating as temperature rises. Note that decomposition of materials often _requires_ energy input, rather than releasing energy. Compare with boiling water: as you approach 100 o​C, water vapor will be produced at increasing rate. But for all water that's boiled off, heat still needs to be added. Boil the water in a pressure vessel, and upon rupture of that vessel result can be spectacular. But if so, to flash-vaporize all water you still need to add enough heat (before vessel ruptures!) to boil off that water.

And regardless of burn energy: because burning organic compounds requires oxygen, burning can only begin *after* a cell has vented. Only the material that's vented can burn, what stays inside the cell doesn't. For every weight % that's non-combustible metal or metal salts (a considerable % for most cells, I think), that's less weight % of combustible material. And not all combustible materials burn equally easy...


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## Gauss163 (May 24, 2015)

Please read more closely. The text was not written by I. It was excerpted from a (very informative) book written by two leading engineers in TI's battery management systems group. Apparently you missed the final quoted sentence "Fortunately, battery combustion is not nearly as fast as that of explosives ...". 

Their scientific claims appear to be well-founded. Of course it goes without saying that the pertinence of the analysis will depend upon the particular application.


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## HKJ (May 24, 2015)

Gauss163 said:


> Please read more closely. The text was not written by I. It was excerpted from a (very informative) book written by two leading engineers in TI's battery management systems group. Apparently you missed the final quoted sentence "Fortunately, battery combustion is not nearly as fast as that of explosives ...".
> 
> Their scientific claims appear to be well-founded. Of course it goes without saying that the pertinence of the analysis will depend upon the particular application.



It does not change the fact that it is scaremongering, they could just as easily compare the battery pack to a small cup of gasoline, but that would not sound nearly as dangerous.


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## Gauss163 (May 24, 2015)

The authors are attempting to convey to the intended audience (designers of (li-ion) battery systems) a rough idea of the amount of combustion energy in a typical 18650 cell. Presumably they are being a bit hyperbolic in order to encourage such designers that safety matters deserve serious consideration. 

The link I gave goes to the exact page in Google Books. One can browse further to get a better idea of the context. 

Please don't confuse my _personal _view on such matters with those of authors that I quote. I suspect that my view is a bit less conservative than the TI engineers, and probably slightly more conservative than the average CPF member.

I think it is important that readers are exposed to healthy _balance _of scientific literature, so that they have at hand the facts to perform their own risk analyses (a highly subjective decision process).


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## magellan (May 25, 2015)

HKJ said:


> *Scaremongering*, try calculating the equivalent number of hand grenades for a filled gas tank on your car (Gasoline as nearly 10 times the energy density of TNT).



Holy sh*t. I think I see a Tesla in my future. 

On the other hand, I'm not as worried now about carrying those hand grenades in my trunk. LOL


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## Gauss163 (May 25, 2015)

HKJ said:


> It does not change the fact that it is scaremongering, they could just as easily compare the battery pack to a small cup of gasoline, but that would not sound nearly as dangerous.



You are missing the point. The book is targeted at readers designing li-ion battery systems (e.g. laptop batteries) that may be used by many millions of users. It is essential that such designers have a good idea of just how dangerous such battery packs can become should they reach thermal runaway. This is not something that many designers would typically have strong intuition about from working with older battery technology.

Generally the risk analyses performed by such designers will be far more conservative than those we may perform for hobby apps (e.g. we are generally far more educated about safety matters than the general public). Nonetheless, the data used in these professional analyses can prove useful for anyone making safety decisions for hobby applications.


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## MrJino (May 25, 2015)

Charged my first 18650, wasnt even depleted and took 4 hours.


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## Arizona_Mike (Apr 15, 2017)

I've learned a bit since I last posted in this thread. I should say that floating them at 4.2v is not good for the cells but due to the very low wattages is not particularly dangerous. Most cells recommend a termination current in their datasheet. In many cases it is significantly higher than what my Nitecore d4 charger terminates on (and my i4 overcharges cells relative to the d4).
I've pretty much moved on from buying LCO and NCA cells to NMC and LMC (LCO/LMO hybrids) for added safety and not having to deal with protection. The LGH2 is my current go-to cell. If I'm going far into the woods I will take NCAs for specific power (less cells and each weighs a bit less) for everything but high drain lamps.

Mike


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## eh4 (Apr 16, 2017)

For me, charging 18650 batteries is about as exciting as charging a phone, but a lot less frequent.

I get more worked up about charging AAA Eneloops, wondering if my cheap charger is doing right by them or not, occasionally feeling the battery to see if it's getting warm or not, wondering if they were discharged enough before they went on the charger, wondering if the charge terminated properly or not.


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