How really dangerous are lipos?

[Busdriver 4676]

Maybe a strange title but I don’t seem to see or hear many stories on this site of actual conflagration??? I have a plan for my TD4 and that is to buy a shorty 2s lipo and install and basically leave it there. My plan is to charge/discharge/storage charge the battery in situ. It will be done in a safe metal box that I have. I will only use the car infrequently and will store it with a lipo alarm attached. Am I being foolhardy 🔥

[Willy iine 12579]

 

Never take safety and good judgment for granted.. 

 

[sosidge 442]

Lipos are only dangerous if you behave like an idiot.

A lipo sat in a car is no more or less likely to spontaneously combust than one in a lipo sack (and spontaneous combustion is very, very, very rare).

Just remember that there are billions of phones in the world with lipo cells in them and hundreds of thousands of RC lipo packs sitting in shops and warehouses with absolutely no attention being paid to them. These places aren't catching fire.

Personally I wouldn't have a setup where I have to leave the LiPo in the car permanently, I'd want to take it out. I'd also put it in storage mode after use and I definitely wouldn't leave it plugged in to the ESC (because most ESCs will cause a small current drain).

I have several LiPos sitting in the cars they are used with instead of a lipo bag. I'm happy with the level of risk.

[nowinaminute 2751]

I would say they are generally very safe as long as you look after them and use them responsibly.

I haven't seen a single issue so far that didn't involve neglect/negligence/abuse etc.

On facebook groups in particular, it always seems to involve using damaged packs, charging damaged packs, over charging or over discharging, using the wrong type of charger or wrong settings, poor cable management leading to shorts, bad solder, wires twisted together instead of soldered etc. And a common theme running through it all is unattended charging.

Even if for some reason your charger decides to go nuts and ignore the correct settings and cut off voltage etc, and cause a perfectly healthy pack to fail, if you actually pay attention, and know how long it roughly takes or the pack to charge, there's just no excuse for allowing a pack to over charge to the point of thermal runaway, it takes a long time to happen and you get a lot of visual warning.

I quite often go up to my charger because I feel like it's taking a while and it's inevitably just on the verge of the charge finishing. You certainly get used to how long it SHOULD take so you would be overly aware if an abnormally long time had passed without the charger beeping to announce it had finished. The problem is that people leave them charging in another room/garage etc and just forget about them and hope nothing goes wrong. Seen a lot of people on facebook who simply left the house with them charging away!

It helps to store them in a safe place with at least some rudimentary fire proofing but to be perfectly honest, It's almost unheard of for a perfectly healthy pack to spontaneously combust while sitting idle and not attached to a charger etc.

You can use a batsafe box or lipo bag etc whilst charging for containment if there was an issue but again, if you're paying proper attention, you would be aware there was an issue way before it escalated , and using boxes and bags etc prevents you from detecting warning signs like puffing etc which begin to happen a significant time before thermal runaway comes into it.

Bottom line is follow all the basic guidelines. Don't over charge, don't over discharge, always balance charge, always storage charge, never continue using swollen or otherwise damaged packs, never continue using packs that refuse to balance or have developed excessive internal resistance, never charge unattended, always use lipo appropriate smart chargers and NEVER use dumb nimh style chargers etc. If you follow those rules and don't get complacent, I'd wager you'd be more likely to lose your home as a result of all the electricity, gas and water that's coursing around it 24/7



 

[Saito2 4791]

I say bring back Nicads.

[alvinlwh 3186]

I will let the pictures of an actual failure speak for itself. This is a vape device with a 800mah battery. It had a faulty charge port that I was unaware of, and when it blew, it flew across the room only to be found 2 months later. Luckily, it blew in the shed. 

Damaged charge port, one screw ripped off. 

Heat damaged paint. 

It deformed forcing the cartridge up and to not sit properly again. 

Melted insides. 

Cracked hinge. 

Probably where most of the heat was when it blew. 

It was so deformed that I cannot tear it apart (without cutting it) to see what the insides are like. 

So now imagine the amount of energy a 3/4/5000mah battery will have 

[alvinlwh 3186]

22 minutes ago, Busdriver said:

store it with a lipo alarm attached. Am I being foolhardy

BTW, DO NOT DO THAT! 

I once stored a car forgetting to disconnect the alarm (my first ever lipo run), it drained the battery right down. 

[Willy iine 12579]

2 hours ago, Saito2 said:

I say bring back Nicads.

I have too many already.. 

[Busdriver 4676]

4 hours ago, alvinlwh said:

I will let the pictures of an actual failure speak for itself. This is a vape device with a 800mah battery. It had a faulty charge port that I was unaware of, and when it blew, it flew across the room only to be found 2 months later. Luckily, it blew in the shed. 

Damaged charge port, one screw ripped off. 

Heat damaged paint. 

It deformed forcing the cartridge up and to not sit properly again. 

Melted insides. 

Cracked hinge. 

Probably where most of the heat was when it blew. 

It was so deformed that I cannot tear it apart (without cutting it) to see what the insides are like. 

So now imagine the amount of energy a 3/4/5000mah battery will have 

And who says smoking was dangerous!!!!

[Busdriver 4676]

Thanks to everyone for their input. I guess it’s a case of minimising the risk by following guidelines. I certainly would not have the battery permanently connected to the esc and I always balance/storage charge my current lipos. The battery would not be fixed into the car merely permanently assigned to it. 

[alvinlwh 3186]

23 minutes ago, Busdriver said:

And who says smoking was dangerous!!!!

I was lucky that this one blew when charging in the shed and not in the house (carpet, etc) but still was a anxious evening as I knew it was smoldering in a corner somewhere but I could not find it. 

[Juls1 1483]

Battery management is everything. 
 

1. Never ever leave battery’s discharged longer than a day. 
2. Never ever leave battery’s charged longer than a day

3. Always store your battery’s at partial charge (30-80%)

4. Never overcharge your battery

5. never over discharge your battery. 

6. if the pack is gets puffy, dispose of it safely, don’t try to keep using it. 

been doing this for 10 years now, before that I had pack after pack die. Since then I’ve only thrown out 1 pack, I’ve got about 16 packs in total some are easily 10 years old. 

[Pablo68 738]

Just make sure you store your LiPo's near things that you don't mind losing in a fire.

I've never had any problems with my LiPo's and I'm probably an example of what not to do.

[silvertriple 2486]

11 hours ago, Busdriver said:

Maybe a strange title but I don’t seem to see or hear many stories on this site of actual conflagration??? I have a plan for my TD4 and that is to buy a shorty 2s lipo and install and basically leave it there. My plan is to charge/discharge/storage charge the battery in situ. It will be done in a safe metal box that I have. I will only use the car infrequently and will store it with a lipo alarm attached. Am I being foolhardy 🔥

storing a lipo attached to a lipo alarm is the most certain way to get the cells down in tension and kill them quickly.

I use lipo and here are the simple rules I apply:

- Always balance charge at 1C within the 24hours before use

- Make sure the motor/esc combos are not using more than the discharge rate allowed by the lipo battery (it is always indicated on the battery)

- Make sure you use the battery with either a lipo cutoff or a lipo alarm set at 3.3V+ per cell. in case you use a motor consumming more than 60A, I avoid runs of more than 10 minutes, and let battery cool down before doing another run (good fro both the car transmission and the battery itself).

- also make sure the lipo balance plug is safe when running the car

- after use, let the battery cool before recharging

- at the end of the day/event : get all the lipo batteries back to storage mode

With all of this, the risks are quite limited. Indeed, the higher level of risk is a shortcut during running time : motor contact unsoldered due to heating, balance charge plug broken, ... But most of this would be the same with a NiMH/NiCad battery.

[Beetlemankurt 389]

Hey Busdriver, very good question as I have seen a lot of scaremongering and horror stories over the years...I would like to share my personal experience.

Apart from my love for Tamiyas, I also do a lot of RC flying. About 8 years ago when I dipped my toe into the field of aircraft, it became pretty clear to me that I would also need to see for myself what this whole lipo thing was about.

I was extremely cautious about it and upon reflection, was actually unnecessarily worried about what I thought would be the equivalent of a hand grenade just waiting for the perfect moment to explode on me....then, I stumbled on a perfectly logical piece of advice...this was to simply treat lipos in the same way you would treat the storage and handling of petrol/fuel.

From a lipo perspective this meant, basically treating them with due respect, storing them in a cool location away from flammable items, follow any provided safety advice, never leave unattended when charging and dont expose them to excessive heat. Basically......don't be a dick :).....

I've now got a sizable collection of lipos up to 6s in size and have actually found them to very easy to use and care for. I charge them always at 1c, always balance charge and use a good charger, use lipo storage sacks and store them in a steel toolbox in the garage.

Yes I've had a few swell slightly as they got old and with lots of use in higher draw situations (helicopters) but I still have some lipos that are about 6 years old that are still in good condition and work well. Others have lasted only a couple of years before disposal or drip in performance. Any sign of puffing and I dispose of them, I see no point in taking unnecessary risk with them. 

In short, I'd recommend them and will happily keep using em. Just grow your knowledge in a safe way and at a speed you feel comfortable with. Have fun!

Kurt

[No Slack 361]

Lipos are dangerous. In our country more than 50% of bikes sold are Electric bikes (Netherlands). RC is minor compared. In recent years two large warehouses with bike batteries burnt down. Also bikes in sheds burn sometimes, etc. And if the fire starts your only hope is you can limit collateral damage.

At work we now use new national guidelines to inspect lipo storages: PGS37 (concept publicatiereeks gevaarlijke stoffen 37). Not for the individual RC driver but..... take care.

 

[Gebbly 125]

I got back into the hobby fairly recently and after reading and seeing videos of accidents with LiPos (and getting rather scared) my decision making process changed from "are LiPos safe and what would I need to do to care for them" to instead "what battery options are out there and which should I choose". From what I could tell (generally speaking) LiPos will give slightly faster performance than NiMH but on the flip side NiMH are safer and easier to look after with less steps needed for basic maintenance.

I only plan to bounce my car around the garden or maybe an empty car park and I'm not getting into competitive racing so I have gone with a NiMH battery for the simpler, safer option. For my purposes the NiMH battery proved more than fast enough for me as the car shot off down the garden.

So I suggest one school of thought could just be how much speed do you need, if you dont need the slight perfomance boost from LiPo then NiMH give an easier, safer life. There are videos on youtube that test the performance difference between a LiPo and a NiMH RC car.

[alvinlwh 3186]

Really, look up UPS6 and decide for yourself.

It is often said that they are only dangerous if you do/do not do x, y, z. They do not self combust, etc... But there are already numerous reports of them blowing up on their own (look up China EV exploding videos), usually due to "faulty manufacturing" (and our batteries probably came from the same factory as those exploding China EVs). Problem is how do you know if that battery in your hand was faulty when it left the factory or not? Which is probably why RM refuses to ship any lithium batteries.

Also look up how lithium batteries are made, the margin for errors are tiny, especially with high capacity batteries. 

Now, being British, everything is about risk assessment, only you can deside if the risk of it happening X harm caused is worth it or not. Personally, I still do use them, just that I pay more attention to them than in the past. 

What I tend to do now is to charge them off a powerbank (not most efficient), which I actually double the risk as there are two lipos involved now, but I also reduce the harm it can cause as I can just toss the lot out if it starts smoking instead of trying to pull plugs.

[moffman 4663]

I'm always aware of the unpredictability of lipo batteries but I don't necessarily worry about leaving them in my buggies I use shorties (actually only have two) and I always make sure they are connected to nothing and no leads are in them they are just a battery with nothing attached just a battery on it's own and I've done that for years but to be honest for what I actually use them for NiMH's are probably just as good for me so it wouldn't really matter if I never had any lipos! I only got the shorties because my cat xls has more space in it and the shorties fit a lot better than a 5000mah NiMh!

[wolfdogstinkus 1565]

I put this down to a dodgy motor. Took out the ESC but the battery was fine!!!!

 

Maybe a little swearing in this video 

[Juggular 4428]

11 hours ago, Gebbly said:

LiPos will give slightly faster performance than NiMH but on the flip side NiMH are safer and easier to look after with less steps needed for basic maintenance.

I agree with that, especially for people who (re)start the hobby.  Why worry about LiPo fire issues for a small gain?  Only when it comes to hotter motors like Super Stock and brushless, you'd be limited by NiMH.  NiMH can give you 2-3A easily.  The silver can and Sport Tuned aren't going to need 2A.  But a brushless could draw 5-6A in the first second, LiPo can supply that but NiMH cannot drain that fast. So NiMH is fine until the motor is upgraded beyond Sport Tuned. 

 

[DTSCB 43]

On a different message board, a guy had two lipos charging for airplanes.  He heard the charger ding to be finished (on the first battery he thinks) and went out for ice cream.  Neighbor called about 25-30 minutes later that his house is on fire.  Happened about 2 months ago. 

 

So, it can happen.  But lipos are pretty common in lots of devices.  I think the risk is really only during charging. 

[Wooders28 4202]

I've read , the chance of a lipo fire, is similar chance of being in a plane crash, so small, but still a chance.

I believe, alot of fires in , the early days, where due to us being used to nicad/nimh, and so just using them wrong (thinking we need to discharge etc), plus when it's new tech, you get, teething issues....

These days, and the likes of LiHv lipos (not known a liHv to go up yet?), being capable of being charged to 8.7v , so when charged to the 'legal' 8.4v, are not being stressed.

Most of the fires I've seen on FB, have been people parallel charging and/or charging at high rates plus not in fire proof bags/box, so not allowing the fire to be contained (you'd be kicked out of our club, if you refused to charge in a charge bag).

Might be the kiss of death, but, I've had issues with a nicad (charging at too high a rate), and a nimh (B6 charger on the wrong setting, resulting in the battery exploding....😳) but zero with lipo.

One shorty I had, when is was rushing for a final, I plugged in the wrong way, and I thought I'd blown the esc. Turned out, there was a small circuit inside, and it dropped down to 1 cell, not sure if it's a safety feature? (Had to put a clip on it though, to discharge before disposal)

 

On 9/16/2022 at 9:23 AM, Gebbly said:

LiPos will give slightly faster performance than NiMH

Slightly? 

I find lipos night and day better, like going from 4k TV, back to CRT TV. 

I thought I'd keep a few nicad & nimh, but once I'd switched to lipo, I've given them all away (think I might have one somewhere...) , as a lipo at low voltage cut off, is around the running voltage of a charged nimh.

I guess if you're running a silver can, it might not be as noticeable, but as you start stepping up motors, the difference gaps gets wider and wider.

 

On 9/15/2022 at 8:08 PM, Busdriver said:

My plan is to charge/discharge/storage charge the battery in situ. It will be done in a safe metal box that I have. I will only use the car infrequently and will store it with a lipo alarm attached. Am I being foolhardy 🔥

If you can charge with the whole car in a flame proof box, and happy with the potential risk to loose your car, when it's being charged, then I don't see an issue tbh (without the lipo alarm though , that'll just drain the battery below 3v per cell, and render it useless).

If you did plan on using it at a club though, they'll require you to charge it in a bag, although, you can argue it is....🤔I'd suggest a liHv shorty, and only charge to 8.4v (as per 'normal' lipo).

I've been looking at the TD4, and was wondering, if it's possible to switch a shorty to run width ways, like the TD2? That would kind of solve your issues? 

[alvinlwh 3186]

1 hour ago, Wooders28 said:

I've read , the chance of a lipo fire, is similar chance of being in a plane crash, so small, but still a chance.

A lipo fire did cause a plane crash! RM's strict no lithium policy came shortly after. 

[Dakratfink 699]

On 9/15/2022 at 4:58 PM, Willy iine said:

I have too many already.. 

 

On 9/15/2022 at 2:29 PM, Saito2 said:

I say bring back Nicads.

Yeah, I really miss 4 minute heat races and 5 minute features where your buggy barely makes it across the finish line on the last lap. Lol 

Joking aside , when I got “back” into the hobby I was blown away by the performance of a standard Nihm pack. Once I finnaly got a lipo pack it was yet another step up. That said , I was intimidated at first of all the safety warnings about lithium batteries at first .