nihm or lipo

[SteveU30 1011]

TBH even with those, some people will have their opinions and thats that pretty much tbh.

Its just good that most of us can talk away and enjoy a good discussion on a subject.

James

Absolutely, some people can't be convinced and I wouldn't want to try. I just like to state the obvious when it comes to safety as those who want to try LiPo should be able to make an informed decision and know what is available.

[Mokei Kagaku 2706]

As others have stated here, handling Lipos incorrectly of course increases the risk, but Lipo as a battery technology is clearly more critical than NiMH or NiCd. I think it's safe to assume that idiots and/or careless people have more problems with Lipos than others, but that's not a valid argument for claiming that Lipos are necessarily safe if you treat them correctly. It would be like claiming that because smokers are more likely to die of cancer at a lower age than non-smokers, non-smokers can't possibly die of cancer before smokers.

There are enough examples of critical problems with Lipos in environments with very high competency too. Boeing is one example, multiple laptop manufacturers have had severe problems, and right now, the company Siku, a traditional diecast car manufacturer in Germany who recently got into Lipo-powered RC-toys, is performing their first recall in their 93 year history because of a safety issue with their Lipo-batteries, despite investing a lot in the development of a safe product in the first place. Just to name a few examples. Also, I don't think Tamiya has decided to go for the much safer LiFePo-technology and accept the lower nominal voltage and energy density just because they're too stupid to go for Lipo.

Living is dangerous and for life to be fun and meaningful, we all have to accept certain levels of risk all the time, but although I'm a Lipo user myself, I can perfectly appreciate why many are reluctant to using Lipo and present valid and sane arguments why.

I worked in the battery industry for some years and have been in the automotive industry the last 14 years, and about one year ago, the combination of these two backgrounds lead to my involvement as QA-responsible in the development of a battery for a major car manufacturer and the next generation of their top of the range sports car. Because of a non-disclosure agreement, I can't tell much, but I can tell that although we are talking about a price range where the cost of the battery and the cost of developing and testing the charging circuitry and battery management aren't of any significant concern, the car manufacturer has specified LiFePo for safety reasons. As anyone with OEM automotive experience can confirm, it's not only about developing the best possible product from a technical viewpoint and more than ever, profit is the main focus, but that doesn't mean that anything is left to chance. Or in other words, when specifying LiFePo for safety reasons, there is a lot of thought behind.

I don't think any of us can predict the future with useable certainty, but personally, I believe that other battery technologies will have replaced Lipo within 10-15 years unless the safety risk is massively reduced. It might even happen sooner. All it takes is one major catastrophe, like an airplane crash or similar where the battery is found to be the root cause, and any manufacturer who uses Lipo will think twice whether Lipo will be acceptable for future products or not. I of course hope dearly this won't happen, but unfortunately, there have been many "warnings" already.

[Mokei Kagaku 2706]

TBH even with those, some people will have their opinions and thats that pretty much tbh.

Its just good that most of us can talk away and enjoy a good discussion on a subject.

James

I worked for a manufacturer of industrial batteries from 1989 to 1993, and we supplied Lithium-Thionylchloride-batteries to the coastguard. These are primary cells contrary to the Lipos, but have many of the same issues when it comes to safety. Accordingly, the batteries were equipped with a safety circuitry that was considered extremely safe. This didn't stop the bunker at our plant from blowing up though and the coastguard experienced losing a light-buoy when one of our batteries exploded. This was something the coastguard had considered being virtually impossible because of the size of the buoy and steel thickness used in the buoys.

I'm not saying that things like this happen all the time or that all owners of a Lipo battery will necessarily see their homes burn down, but the high energy density and the runaway-effect once something happens mean a risk that isn't associated with most other battery technologies.

[speedy_w_beans 4272]

My next door neighbor bought a brushless 4WD buggy for his son for Christmas. It came with a 3800 mAh NiMH stick pack and a wall wart charger. The wall wart took forever to charge the battery, so he asked me for some advice about batteries and chargers. I steered him towards another NiMH pack and a peak charger because he and his son are not the types to pay close attention to a battery and all the rules for using a LiPo. I really don't think they would understand low voltage cutoff, balance charging, storage charging, and safety for LiPos. They have a lot of expensive automobiles in their garage and had to deal with flood damage a year ago, so I could only imagine a worst case scenario of their house going up in flames due to mishandling or not keeping a close eye on the batteries. NiMH is definitely more of a set and forget technology after configuring the charger the first time. His son will play with that buggy often enough that cycling the pack to keep it healthy will not be an issue.

I accept the risks associated with LiPos to enjoy their performance and maintenance benefits. To mitigate the risks, I have a few strategies in place to deal with situations when they go wrong. Some people might not want to deal with the risks and put new measures in place; that's perfectly fine. To each his own. If someone new to the hobby asks for battery advice, I'll point him to NiMH for less risk and less liability.

[JeepnMike 150]

For vintage I use NiMh. For modern more race oriented cars I run LiPo. If I could run LiPo in everything, I would. They perform so much better, they don't progressively degrade as the battery discharghes like NiMh, just all around so much better.

[danb1974 93]

Just as a note, lithium batteries are used in cellphones, laptops, tablets etc. And there are phones and laptops catching fire now and then. Luckily they all include protection circuitry into the battery, you can't just overcharge them by mistake, but they are not 100% safe.

[NWarty 1325]

Dan,

My Dad's HobbyKing charger had all that stuff in place and my parent's basement still went up in flames. Like I said in several posts before, his settings were correct and the insurance company is going after HK for garbage failsafes.

Their NA warehouse is 15 miles from me and I'll never order a single thing from them again

Five years ago I scoffed at the idea of a lipo fire until it happened to my Dad. Their entire basement and first floor was replaced due to fire and smoke damage.

This is not hearsay, this stuff happens and god they're lucky

[lentner3 281]

hi - well, to answer your questions... no i actually don't eat much tuna (if any) these days, primarily because of the mercury issue. and i certainly don't feed it to my son. i don't think they use metal fillings anymore, do they? our dentist doesn't... it's porcelain or something tooth colored. so it isn't a case of me being ill-informed or hypocritical.

the wires that melted on the heli were definitely the ones that went from the battery to the ESC (the ESC also fried), and again, it's not very useful to suspect that i can't tell the difference. and it was definitely just a case of using a higher C battery. it was the same number of cells, same voltage, but something like 30C instead of 20C. i was always up to that point trying to push the limit on how much battery i could get into the helis to try to get more performance or airtime. i stopped doing so after that scare. you pretty much can't really grasp the danger viscerally until you experience it - i felt a lot more confident playing around with LiPos by trial and error before that incident.

what i really, truly would love for someone to do in one of these threads discussing LiPo vs NiMH ... there is inevitably one or more people who tell of their experiences with exploding NiMH or NiCd batteries in the past, meant either to make LiPo seem like the safer option, or at least no worse. but in pretty much all the cases i've heard of people admit that they were using some rapid charger, jamming charges into the batteries in as little time as possible, intentionally overcharging them, etc. i've never heard of a case of a NiMH or NiCd pack incinerating a buggy after hitting a bump while being driven, etc. it's always during charging and usually charging that's pushing the limits.

so... back to what i would love - i can go on youtube and find video after video of LiPos burning up and exploding. i can find loads of stories of people's houses, garages and 1:1 cars being burned down or incinerated. i can find loads of examples of R/C's catching fire and going up in flames because of some issue with the LiPo. BUT i've never, ever had someone actually find me a video of anything burning or blowing up because of a NiMH or NiCd battery. i believe the stories that they can go *boom*, make a loud sound, etc if you charge them abusively. but that's all. as far as i've ever heard there was no "...and then the house burned down" in any of the stories.

i'd be grateful if someone could dig up some volume of evidence of the dangers of NiMH/Cd batteries so i could at least get a good grasp of exactly what my choice of battery may have in store for me under the wrong circumstances. but if the paucity of documentary evidence of NiMH disaster compared to the plentiful examples of LiPo disaster is any indication on it's face, i think it wouldn't take an insurance adjuster to figure out which one is a greater risk to life and property.

here are a few of LiPo damage/danger:

(the list goes on and on)

and here is one of the only ones of NiMH burning... which they really had to try hard to make burn up (probably overcharge it, short it out, etc - not super likely normal conditions) and even then the fire can only be described as tame compared to any of the LiPo fires... and it looks like they used a pretty serious NiMH as well:

(just copy the URLs as it isn't bringing up the youtube windows or hyperlinks after the first 2)

Please don't think I was questioning your intelligence. I never suggested you were ill informed,careless or hypocritical and hope you didn't take any offence to my comments.

I also never made fun or dissregarded your argument as invalid as I do feel you have some very good points. Your more than entitled to your opinion.

I too have never had an issue with my lipos even getting hot but I have with my Nihm and Nicad packs. One thing that does concern me however is the extent of the fire if one does occur.

Being an electrical/chemical fire chucking a blanket or water over it isn't going to do much so I may invest in an extinguisher and some smoke alarms.

And to anyone using Lipos please never charge unattended, from what I can gather lipo fire tend to happen when charging or discharging. I have a metal tin for min and I also store them in a vented metal case aswell as in lipo bags. Never charge higher than 1C and always be carefull when connecting and inspecting wires. Bit of common sense goes a long way. I myself feel I can reduce the risk to a reasonable level. By the way they still use amalgum fillings in the UK and after lots of investigations they are deemed safe. (this i'm not so convinced of)

[Vrdetailing 1241]

Life is full of risks.... And statistics of a lipo killing you are very small.. I ride a harley, Drive a sports car, Drink too much and Do lots of martial arts

I charge in a metal tin and store in Stonebake ovenware with a vented lid on.

My recommendations for Tamiya

http://www.hobbyking.com/hobbyking/store/__6478__IMAX_B6_AC_Charger_Discharger_1_6_Cells_GENUINE_.html?strSearch=imax

http://www.hobbyking.com/hobbyking/store/__29001__Turnigy_5000mAh_2S1P_20C_hardcase_pack_ROAR_APPROVED_UK_Warehouse_.html?strSearch=5000mah roar

http://www.hobbyking.com/hobbyking/store/__26724__Turnigy_3300mAh_2S_30C_Lipo_Pack_UK_Warehouse_.html?strSearch=3300 2s

[JeepnMike 150]

These threads are interesting. If you ever go to a track, you will see probably 40 (at least, at a single time) LiPo packs being charged, and not a single one in a LiPo bag or any sort of container. I think 99% of the people who use LiPo regularly have come to the conclusion that if a pack is handled and charged correctly, you will never have a problem with a LiPo pack. Obviously if you mis-handle or charge incorrectly you are opening yourself up for a disaster. There is always a thread like this once a year and it scares away any new guys from considering LiPo. I think sometimes the alarmist attitude should be toned down and replaced with sensible knowledge transfer. I definitely think there is a certain group of folks who LiPo isn't for as Speedy mentioned above and I have pointed new folks in a similar direction with NiMh knowing they didn't have the attention span and focus required for LiPo. These threads branding LiPo as ticking time bombs are a bit misleading though.

[lentner3 281]

I don't care anymore 😵😴

[Mokei Kagaku 2706]

I think 99% of the people who use LiPo regularly have come to the conclusion that if a pack is handled and charged correctly, you will never have a problem with a LiPo pack.

How are we supposed to understand this?

1. The regular hobbyist who has never experienced any problems with LiPo is more knowledgeable about batteries and treat them more professionally than the battery specialists at Sony, Apple, Lenovo, Panasonic, Boeing etc., who have actually experienced massive problems?

2. Is it simply because the battery specialists don't have "the attention span and focus required for LiPo"?

3. 99% don't experience any problems, while the remaining 1% do? If so, that would be considered an enormous risk by anyone with risk assessment experience.

4. ?

I think sometimes the alarmist attitude should be toned down and replaced with sensible knowledge transfer.

And with all due respect, simply concluding that "handled and charged correctly, you will never have a problem with a LiPo pack", is then supposed to be a more "sensible knowledge transfer" despite the fact that there exist numerous highly qualified and experienced companies specialized on battery technology that would love to confirm that LiPo is 100% safe if treated correctly, but simply can't because there is so much empirical evidence that says it's not?

As before, I'm not saying that all LiPo-users will experience severe safety problems, but quite a few do and not all of them are idiots, and I think it's negligent to conclude that LiPo is safe if treated correctly, just because the majority don't have any problems.

Btw, for a fair share of thermal incidents with LiPo batteries, the root cause has been contaminated electrode material, something that is 100% beyond the control of the user, regardless of knowledge level.

[JeepnMike 150]

My post wasn't intended to be informational, nor was it intended to be argumentative. I can see you would prefer to be argumentative so I will let this one fizzle.

[Mokei Kagaku 2706]

My post wasn't intended to be informational, nor was it intended to be argumentative. I can see you would prefer to be argumentative so I will let this one fizzle.

So, those of us that aren't convinced that LiPo is absolutely safe when handled correctly are "argumentative" and don't have the right to defend ourselves with rational arguments when being accused (more or less directly) of being idiots and less knowledgeable than you and others that are fully convinced that LiPo is safe? And we don't deserve to be treated with the same respect that we treat you?

I'm not at all looking for a fight, but simply to contribute to a not too overly biased view on LiPos in either direction in this thread. However, If black & white "absolute truths" is what's considered politically correct here, please disregard all arguments that may not suit the purpose of quickly and comfortably jumping to whatever conclusion considered "right".

[lentner3 281]

oooooo time to calm down me thinks? Someone is twisting someone elses words. No one called anyone an idiot or less knowledgeable or even insinuated such things. I don't know how you came to that conclusion. No one is here to offend but to share our experiences and knowledge. No one has even said there is wrong or right only that we have different takes on the level of risk and how we percieve it. I think that was a bit harsh and you seem overly defensive. There is no need you are entitled to have your say and be heard and noone is disregarding that. Please don't try and cause an argument when there isn't one.

[JeepnMike 150]

Ah, now I get it. You are reading my tone wrong dude. I wasn't calling anybody an idiot about their ability to handle or not handle LiPo cells correctly. I was talking about examples such as Speedy pointed out where LiPo would NOT be recommended.. A neighbor who he knows will leave batteries charging unattended. Or in my two recent cases of friends looking to get into the hobby, one of which has younger kids that will be charging the packs and I know they won't know or care about what they are doing, they just want a charged battery, so I of course suggested NiMh. I have another friend getting into the hobby "Traxxas style" who wanted to upgrade batteries and chargers and I know he too won't pay attention to charge rates and likely will leave them charging unattended so I steered him to NiMh. I wasn't calling anybody an idiot at all and was agreeing that LiPo isn't for everyone and I am definitely not an expert on battery technology, just a happy user of LiPo, and NiMh as well. My point you have backwards sort of. LiPo can be perfectly safe, just not for everyone and whey I say not for everyone, that isn't to question their intelligence, it means just that, it isn't for everyone.

[Mokei Kagaku 2706]

Lentner3 and JeepnMike, thank you both for contributing to calming the thread down!

I don't at all want to escalate this discussion (again? ), but I definitely don't agree that "LiPo can be perfectly safe", as I think there is a risk involved that can't be excluded regardless how careful and knowledgeable the user is. And of course it's not about LiPo necessarily being less reliable than any other battery technology, but about the typical consequences when something goes wrong.

Anyway, people are taking different decisions all the time. Those aversive to risk may sometimes miss good things in life, whereas those prepared to accept higher risk, may sometimes be slapped by "fate". In their extremes two completely different life philosophies and a discussion here won't change that. Being neither fully for nor fully against LiPo, I would personally appreciate if both camps would abstain from making a firm b&w conclusion for LiPo's total safety or total lack thereof, because I think neither conclusion would be justified. But without the slightest of irony, that's only my two cent.

Gentlemen, have a nice evening, night or day, depending on where you are!

[Vrdetailing 1241]

Nothing in life is perfectly safe... If lipo was so dangerous they would be banned... The lipo danger and hard case soft case argument get a bit boring so agree to disagree.

Petrol is more dangerous than a lipo... Do we slate petrol rc cars ??

A 750 size helicopter killed a man recently... Do we still fly ???

Motorcycles are dangerous... Do I still ride...

The answer is yes with the risks fully understood

[hammerstien 187]

in racing in the last year seen more nihms vent at races than lipo's balloon and had the burns from the chemicals as a reminder old used nihms are dangerous had one vent in my grasshopper now needs new chassis

[beefmuffin 1156]

If lipo was so dangerous they would be banned...

i don't mean to poke a hornets nest (like what i did there? hornet ... ahem) but stating that if something was dangerous then it would be banned right now is always false for every 'something' for some period of time. like this nifty insect-repelling DDT wallpaper for children.

The answer is yes with the risks fully understood

exactly the point. fully understanding risk can't be done optimistically. you have to look long and hard at potentialities.

anyway - i think this thread now has a good mix of ideas to help people make their own informed decisions ... and that, after all, is the point of all this isn't it?

[JeepnMike 150]

I agree they would be banned if they were dangerous when used correctly and the benefits of LiPo for anybody who wants performance is pretty much a requirement now. There isn't a single performance car with a battery tray suitable for anything BUT LiPo now. Go to a track and see what everyone is running if you want to put some reality on it, you would likely get chuckled at if you were running anything else.

With that...

[NWarty 1325]

Sexual chocolate?

[JeepnMike 150]

LOL!! Not sure how many will see the humor in that.. I thought it was fitting and a mood lifter

[speedy_w_beans 4272]

Bumped into something interesting this morning. One of the local universities is working with a different electrolyte for lithium ion batteries (LiPo is classified as a lithium ion technology) that makes the battery nonflammable.

Link: http://www.unc.edu/campus-updates/researchers-build-nonflammable-lithium-ion-battery/

[Shaggy39 43]

Lipo all the way for me and cheap too now. I have been using them in helis for 10 years and I remember the rc car fraternity looking in horror when told them I was using lipos in my cars at a race meet about 7 years ago.

The scaremongering about them being dangerous is unfair. They are like any other battery, need to be respected as all batteries are explosive. I have heard of a house being burnt down due to two triple a batteries shorting out in a metal tray! A lot has changed since they were first released and people should know how to safely charge them. I remember a guy at a car race meet unplug a nimh pack from a nimh/nicad charger and then swap it for a lipo and try to charge it with the same setting and couldn't understand why it wouldn't work!

And as a final note. I can vouch that all batteries are dangerous as I managed to destroy my car (and I mean real car, vw Jetta) by leaving a charging battery under the bonnet as I drove away from a flying session!