He talks about the dangers of 18650 batteries while taking a torch lighter to one.... great job buddy, really upping the safety factor there!

I'm an Electromechannical Engineering Technologist. I have designed many 18650 Lithium-ion Power packs for 6 years now. Did lots of research and tests on them.............and I have to tell you, I'M STILL SCARED OF THE DAMN THINGS!!!. I have seen the damage they have done to property, machines, People, laptops exploding at airports and business meetings...etc.

should have put the plastic ring back on there... Just saying...

So two main problems I saw with your video. the thick wire wrap you used does not properly let it dissipate heat. all batteries have a nominal operating temperature. different chemistries of batteries have different levels. if the battery stays at or above that threshold you risk permanently damaging the cell or it vents or catches fire. also you shouldn't have double wrapped it with your wrap and the original it came with. way more plastic to hold that heat. 2 you removed the plastic insulator ring. that ring is a thick piece of plastic designed that if the battery wrap were to be damaged, that thick tough ring should stop anything to lay across and short it out.

So glad someone else knows about this. I had a big Smok X Cube, which unfortunately uses 18650's and you need to get the fast discharge versions too. The big problem is that the X cube can't self charge, so you regularly have to remove the batteries and put them back in again. After 5 days of having one, I'd encountered what a big short was. The battery housing was so tight that it scraped off the protective ring of the battery and shorted them. This resulted in what I can only describe as a firework flying round my living room. I got burns to my hip which have left a scar and the living room needed to be redecorated. Back on real cigs again now. ahhhhh....much safer.

Appreciate the informative nature of the video, although I'm sure you've heard this many times before this is NOT a design specific to the 18650. This is the design of almost all cylindrical cells for the last couple of decades. You can verify this by taking apart a standard household AA alkaline battery. It does seem kind of strange though with the lithium cells on the market now capable of delivering more than enough power to damage themselves and surrounding cells before discharging you'd think the design would have been improved by now.

Put one of these in the same pocket as your car keys and you may go to the emergency room or worse. Thanks for showing how easy it is to short out. I think disposing of the battery once the protection starts to wear away would be best for people using these in portable devices.

Great video. I thought the same thing about the entire barrel being negative. I am glad someone took the time to take one apart and show it. This video should be required viewing for anyone who is undertaking a DIY project using 18650's. Makes me rethink spring contact battery holders for these cells as well.

I was also naive thinking that the positive and negative were only on the opposing ends until just recently I noticed sparks when I plugged a 18650 with a worn coating on the positive end to my e-cig. The battery started leaking right away. I'm glad that I found out this without a more sevear accident! Great vid! I agree that the insulation on these is way too thin and prone to wear off with just normal plugging and unplugging of the battery!

I saw your whole video and confirm its informative and "safe" , even without the added comments (which still are good addition). Your points are clear for the general audience so please ignore the senseless comments below.

Very informative, thanks for the advise. I got myself some good shrink tubes to wrap my batteries.

great video and teaching on safety regarding the 18650 lithium-battery. Wow all you have to do to make them safer is to heat shrink (wrap) them.

Lets work with flames on a battery, to make it safer. :D

Good attempt at making the 18650 safer, but you should have re-installed the ring insulator before you used the heatshrink. Hopefully you can still accurately indentify the positive ends after you wrap them with shrink.

Thanks for this, really helpful!

What got me is the title of the video claiming to make them safer, but in said video you dead short low-drain (probably ICR) to show the neg-pos thing. Even a quick dead short can cause venting. And, I think there is more danger potential with using a wrap that insulates the heat in the battery. If someone has enough know-how to make a battery pack, I am pretty sure they know about the positive and negative post and definitely know not to tamper with or remove the wrap. If the thicker heat shrink only fits *your* purpose, since you say you'll be using it in a go-kart with adequate airflow to keep them cool, I think the video should reflect that the wraps will work for situations like that, It's not making them safer for your audience if they're not using them in the same way.

So now, how do you distinguish the positive and negative terminals? The scratching really isn't too much of an issue, the "dangerous" part is protected by the little plastic ring you removed. But I gotta say, the black does look a lot better :)

Thanks for this video. I'll do it same way as you.

Great Advice, Thank You!

I don't understand all the dislikes as this video is very informative...

Ha Ha you cant be serius ..... Removes the isolation ring that prevents short circuit and then heats the hole thing over an open flame xD

Did you consider the thermal properties of the original plastic coating vs. the shrink wrap you are replacing it with? The batteries need to have a way to release heat - might not be much, but with every degree they are warmer, they perform worse...

It's an interesting peek into the anatomy of a battery and i really like the first part of the video. I would, however, advice against replicating the part where you roll your own insulation due to (as others are saying as well) changed heat dissipation characteristics and cell dimensions and it appears the custom isolation is not better than stock (remember that fairly thick plastic ring you removed?). I would also be nervous about using a torch on a li-ion cell, but as you say its not really heating the cell.

Fear and Ignorance always a big seller.

Question. Is that tubing designed to be a battery wrap? Also are you returning the insulator ring before heat shrinking it or?

this very thing caused me to have very severe 3rd degree burns on both my legs that required skin grafts.. Those of you criticizing this man and have never been severely burned keep doing what your doing im sure you will see why he posted this sooner or later.

Just make a better end cap to protect the + and the edge of the -

Very informative, Thanks

You are placing a thicker, more insulating layer which prevents the batteries from cooling as efficiently. Heat dissipation in a battery, particularly Lithium, is important. While I agree that having the terminal so close is an odd design, battery designers, in general, are well aware of what they are doing... Laptop battery packs are generally well soldered and nowadays have a very low failure rate.

Nice job on the video keep up the great work, at 10:00 how did you make that lighter that is made for grills and lighting candles how did you make it act like a blow torch?

The plastic ring and heat shrink are perfectly adequate. Unless you hold your soldering iron on for too long and melt it. Your dealing with 4.2v at the most,it's not going to jump the gap by any means and those with the new heat shrink wouldn't fit in a 18650 torch anymore.

have 2 batteries that wrap has small tear along the negative body. Patched it with electrical tape. have been monitoring them for a week amd so far no overheating. is that safe though if its only along the long side?

Good job !! have you got a link to the heatshrink are you using ?

What's the size of the shrink wrap you used? 20mm?

why remove the protective ring what if sum conductive things slips through or sum conductive dust builds up there?

may be protected from bouncing and shorting but it will retain heat like a s.o.b. manufacturers put specific coatings on certain products for a reason and this coating helps the battery vent

So what your video has shown me is, Do not remove the plastic ring at top. Obviously it is there to prevent the bridge. Why would you possibly take it apart to show that? They are designed that way for a reason. Leave the ring, right?

does 18650 requires an overcharge proyection and if yes then how to build that cutoff circuit

Good explanation on the fire risk of 18650 battery. Shall take necessary preacuation.

Hello Is it not better use, liquid tape with the plastic ring on the top? Regards Thomas

Very useful tip thanks 😊 👍

Great video! Would that piping fit a 18500 battery?

thanx, I did not know this about the negative body

Wow that seems a little sketchy having positive and negative so close to together. I am glad I watched this. That's good to know. It looks like you could potentially short out a battery just by spilling a little water on the top of the battery.

i thought this was already known, thats why they make the insulating rings

With the heavier jacket will they fit in flash lite ?

When making videos about these batteries , I think a prior video should be shown of how dangerous these can be and what happens. Then people will think twice about relying on factory wrap.

The information is perfect, but the execution is dangerous. You never put heat on a lithium battery, and you also never short-circuit a lithium battery without protection.

Andrew thank you very much for the informed video that you made and which many people who speak about this subject regarding 18650 lithium battery cells overlook. My questions happens to do with handling 18650 batteries coming from an old laptop/notebook battery that I took apart; Q. How does one discharge charged 18650 batteries that all currently fully or partial charged and since the batteries came in pairs how to I remove the metal connector on the positive and negative without arcing myself or causing them to explode? Also, these batteries I am experimenting with are for a power bank charger used on smartphone - Iphones, Android and I would like to know more about its handling safely and it is proper to use such batteries for this project?

Use the nylon washer you removed as its more durable than just your shrink tubing If you are building packs for motorized scooter or other high impact items use the plastic holders designed for them You can see a sample of these being used on the electric samba page

I went back and watched your video again and you were right, I stand corrected.

Thank you for sharing

Thanks for the post. You potentially saved me money before my batteries come. Thank you.

I do a lot of these shrink wrapped batteries and yes it was silly to take off the protective plastic ring. Also you should have left the ring on when shrinking and if you have a lot to do it is so much easier to stick them under a grill and watch them all shrink together. These batteries will take some heat as they do get hot in extreme usage anyway.

Very informative.

i would have made sure the positive end was lined up and shrank first correctly so all trimming and adjustment can happen on the safe negative terminal

what brand is the battery you start this with? I have this battery from a ecig mod I ordered and cant find what kind of battery it is?

I want to ask you, I have a fairly new 18650 battery, but earlier I dropped it and it spit out a liquid like water, I checked the voltage is still normal, is this not dangerous if I still use the battery?

Will they slide into a flashlight ? Once in light can they be removed ? Seems to me a tube designed for protection would be in order ? A battery carrier designed to carry multiple batteries perhaps?

What size heatshrink did you use?

6:50 I'm glad you discovered this too

thank you. a lot of people bitching about how dangerous litium ions are (and yes they sure can be) you are one of the few that expressed some of those concerns in a constructive way with education. next up someone needs to do a video on ir testing with a scope and signal gen. that might be me soon but im still building my lab. I was in a commercial space but the owner of the "electronics repair" store attempt knew nothing and didnt want to put any future profit sharing in writing even though he was using 5k worth of my equiptment every day. so my apt/flat is currently being converted which is a major pain in the ass. BTW get yourself a 50 usd adjustable temp heat gun on ebay "smd rework station"

It's very interesting topic, and I'm glad that you came with this idea. I'm a user of an electronic cigarettes, so i have this batteries just in front of my face... How about 18650 batteries but with "pin" top, not the flat top, do you think they are safer or it's the same problem? PS: I didn't ripping of the plastic from the pinned one, so i don't know how it looks like inside.

You mentioned when you were getting sparks while opening laptop battery packs, generally if a lipo battery shorts out on itself it's done like dinner for good.

great idea thank you!!!!

Would it be safe to use insulation tape instead of the rubber tube?

Andrew I know exactly what your saying I was very concerned also so when I built my 147 ah pack for my solar power, I also wrapped all the cells inside a fire blanket, then added vents and sealed the whole lot up in Robnor Resin the fire retardant stuff semi flexible it has a texture similar to Rubber.

Thanks dear!

Perhaps the original covering was designed to permit the proper amount of thermal transfer as these batteries often have a high current draw and need to dissipate heat. Also you did not replace the plastic ring insulator. Batteries meant for flashlights and portable equipment should have the protection circuits built into them which will also prevent short circuits, over voltage and under voltage. Batteries out of a laptop power supply do not have protection circuits as this circuit is provided by the equipment. One thing to keep in mind though is that a lithium ion battery when permitted to discharge below (over time) it's safe low voltage level can catch fire as internally copper crystals can form a short circuit. Keep your lithium batteries charged and do not store long term without topping them up. When they are worn out - dispose of them properly. Lithium Ion batteries are wonderful for their large capacity but you do need to educate yourself in their use. As far as the negative and positive terminals being close - you can say the same thing about a typical 9 volt battery. Ever put one of those in your pocket with a handful of conductive coins ;) Why are my pants getting so hot?!!! ;)

Hahahaha you take the protective ring off then claim it's unsafe.... I have about 16 of these 18650's and use them in a variety of dive torches, never had an issue.

Very helpful

Was wondering if replacing the coating with a heavier wrap would cause the battery to retain the small heat that they make under normal usage to actually over heat the battery and shorten its lifespan?

you do not need to heat shrink the whole battery..just put on a half inch or so of heat shrink on the positive end...

How about a tight fitting vinyl cap to cover pos+ end of battery ?

Nice video, trouble is manufactures use cheap heat shrink most batteries on the market are the same.

Do I need bms when I already have Mppt/pmw

Maybe it's only me, but please, people if you intend to modify those batteries in that way, make sure you do not cover the venting holes on + side.

I have a .5 build Tesla Invader II with 18650 MXJO batteries. I'm new to vaping and my problem is that I can charge the batteries for 2 hours using a Nitecore charger, and my batteries will discharge and become weaker after 25 minutes of usage? These are brand new MXJO 3000 mAh batteries btw, any solutions???

thaks for the advice can u tell me please how can i charge them with out buying i charger ? or can i use i normal computer charger ? directly ? or any idea ^^ thanks

very nice and helpful video ! next time could you please keep the camera a little further.

The most dangerous video I have ever seen on KZfaq I hope no one follows

Ahh, just like that time Gilligan rewired the professors beacon signal when they heard on the coconut radio that the air force would be testing in the area. Well done sir, well done.

Very good video.

THANK YOU! this is very useful and vital information! that's just ridiculous to make a battery like that! they couldn't possibly make the production so that they include an insulator SOMEWHERE, literally ANYWHERE further away from RIGHT NEXT TO THE DAMN POSITIVE?? that's an absolutely terrible design. They need to include information along the lines of DO NOT USE IF THE WRAP ISN'T PERFECTLY INTACT.

So you rip off all the protection and it explodes. So if you don't rip off the protection, does it still explode?

what size heat-shrink is that?

thanks much!

ALLL batteries have negative body. Well there is few mostly 9volts, but rest is always negative whole battery and i think everybody who uses batteries knows that :)

thats very r8 ...n nice informative vid... but last month with one of my projects i noticed that when iam connecting the negative part of the batteries near the positive(above the indented rim) iam getting different battery life and charge readings although when i connected the negative part of battery at the extreme end i got better battery life and more accurate battery charge readings...i got same result with 3 different setups.... cd not explain to myself why its happening as its a single complete negative shell.....just want to know if anyone else experienced the same or if anyone can explain it......

You can use artist tape to isolate them.

this would increase internal resistance as head would now be an issue?

Panasonic makes 18650A batteries. Is this the same for them or what is the difference?

what size heat shrink wray do i need ?

Can u do the same with electrical tape cuz I don't know where to find that electrical tubing

Good video, are you from Bristol?

omg. I already know that. simpel stuff. but thanks any way. :-) :-) :-)

I have seen a video of one shorted. It looked like 4th of July fireworks so be careful not to short them. You might also want to get a paint marker and mark positive and negative since they now look almost the same. A paint marker is similar to a permanent marker and sticks to more surfaces. It will still wash off with some solvent easily like permanent marker.

Good idea to wrap up the battery were can I get does black wrap around tanks let you know please contact me.

I would say that all A, AA, AAA batteries has similar construction and even NiCd and NiMH will cause heat and burn if you shorten them out. No news, has been like this for 15-20 years at least..

At 1:34 of the video you briefly talk about the "little plastic cap on top". This is a ring insulator which is there to prevent the exact problem you are trying to solve against in the entire video. The insulator is thicker than the wrap which you are applying and I bet it does a better job at protecting against a short. In short, the battery design already accounts for the danger which you are highlighting and all needed components are in place to prevent the short from happening.