The experience that Shufflez has been through brings up an interesting question. Because, like Choppersrule, I think that we have probably offered about all of the wisdom that Shufflez needs, I'll start a new thread rather than hyjack the original. I hope that the interested parties connect to this one to help me out with my thoughts.

SUBJECT: NiMH cell safety
I use NiMH cells in my Walkman Radio thing, MP3 player, three digital cameras, three RC Tx units and number of kids toys, etc, etc. From the sound of this thread it sounds like anyone using NiMH cells is at risk of meltdown. For my self, and only from my perspective on this matter, I am not buying it. Shufflez had an explosion, and I will not make light of it, but I do not believe that everyone with NiMH cells in devices on their person or in their homes is in danger. I believe that brand name cells from any premium supplier are safe to use within the capabilities and guidelines for use of those cells. From this discussion, I am now of the opinion that some of the no-name cells may be suspect and I'll replace those that I use with brand name cells. It's just my opinion, and I am certainly no expert.

If I am missing something, help me out here. I'm not trying to run over anyone, but I think that somewhere in this mess we got lost. And of course I'm open to other's thoughts.

Soloboss

Did he overcharge the battery?

I have never had any fire/explosion with any NiMH. I've had them overcharged for weeks and have layed them in direct sunlight all day. My dog has even chewed up one and she is still alive. As for battery safety I still believe that they are much better if compaired to Li-poly and Li-Ion.
I've done some light research on the three types of batteries at wikipedia.org .
As for the manufacture who makes the batteries might have low quality control, but are probably built within a U.S code standards, if not then it never got caught at customs.
I believe that newer NiHM batteries contain catalysts to prevent it from overheating and fire.

Hey Solo,
Have you seen the boiling blades video?

what boiling blades video?

No, I haven't seen the boiling blades video. Link me please!
Inquiring minds want to know.

sorry I've changed the subject.

The orignal post under this listing http://www.rcuniverse.com/forum/m_6721538/tm.htm

video link is

http://youtube.com/watch?v=RmNv8OlG6GQ

oic

Back on topic, I would have to say that it was a rare fluke! I have had more nicad powered devices that you can shake a stick at and nothing has blown up with that kind of an outcome? Actually I don't ever remember even seeing an incident with nicads that severe. I wish I knew more about batteries, the explosion is caused by the expanding gasses being held in check by the plastic wrap of the pack, then by the case itself. As kids we used to build match bombs using a similar practice, electricians tape worked the best, but I digress. What would cause a single nicad cell to go into melt down like that? Opens the door to alot of questions. I still think it's one of those rare things that happen.....similar to an event I had with a new extension cord once....but that's a topic for another thread

To All:

I'm with Stump3r, it was an extremely RARE fluke. I always think BIG, meaning world wide things. Hmmm, I'd bet that there are maybe a billion Nicad, NiMH and Lipo batteries world wide. Every Cell phone has a some kind of battery in it and they CLAIM it can give you cancer. Give me a break. I saw tonight on Satellite TV, where Energizer makes a million batteries a day. How about Pepsi, Coke or even Milk, gosh, think of the gallons of that stuff.

Like any topic, it can be debated forever. Just me being smart here, DON'T get out of bed in the morning, you could trip and break your neck.

Think Big and World Wide, there's like 6.3 billion people in this world, that's alot of Big Mac's.
If everyone drank 64 ounces of fluid per day, and you have to or you'll dehydrate, that's 3.15 billion gallons of stuff EVERYDAY.

Take care guys, and start thinking big, (Yuk-yuk),

Dave / Choppersrule
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that also hit me, cause when i went to hobbytown usa the other day, 75% of their batt packs were nimh - i was taken a bit aback, then i remembered that lipos are really new, and that nimh has been around for a long time, ever since nicad went away, and is in most everything

i haven't been into rc at all since the 70's, so others would know more than me, but aren't all of the electric rc cars using nimh? - do they explode on a regular basis?

i used nimh packs when learning to fly the fp cause they don't turn into a flamethrower when you hit something sharp with the lipo

is the secret of nimh that they explode? - is it a dutch power thing? - we may never know

i know from experience that lipos can turn into flamethrowers, but from my portable home phones to the batteries in my laptop computers, i use nimh on a daily basis and they have never exploded or even melted down

could the spektrum supplier be making crap? - quite possibly - should i replace the 2200 nimh in my dx7 with a lipo? - i'd say yes, but mainly cause the nimh needs that electric blanket plug in, gets charge memory and runs out sooner than a lipo, but once you change to the lipo you can't charge it in the tx, which is one of the things that i think may be going on here - but once you go lipo, what is the extra voltage doing to your tx?


edge

Maybe the problem isn't in the battery. I know it was the battery that fired up, but what caused it? It could of been the controller having a short that caused the battery to fry. Even if its a high end battery company a short circuit would still fry the battery. Compare how many batterys are made and how many controllers and look at the track record of defectiveness. I'd place my bet on the controller frying out the battery.

A NIMH has the possibility of malfunctioning if it is overcharged.

I won't bet my life on it but this is what I've read on NiMH "Modern NiMH batteries contain catalysts to immediately deal with gases developed as a result of over-charging without being harmed (2 H2 + O2 ---catalyst → 2 H2O)."

Edge--


Most of the RC-cars do run on NiMh. Some RTR's come with NiCad's still. I've run both in my RC-cars and have never had a problem. One of the systems I run the NiMh has gotten so hot, you couldn't hold it, or when you picked it up, the cells were so mushy and soft, the pack would collapse over...Lol..(Not good...High power, cheap connectors...Lol..) Plus I was over-geared a few teeth. But I've also accidently arched the two wires together before and they literally stuck together, and got glowing orange in color (About the time you start to think you should chuck it...Lol..) and still never had a problem with the NiMh's...I also run the NiMh's like all, in all my gadgets etc. etc. and never had issues. Just a fluke thing with Shufflez DX-7 unfortunately. I'am thinking the Dx-7 is of good material, but I bet they skimped (blowing up or not) on the Batt for it. It drains fast, and takes some time to charge it anyway, so I would be interested in replacing it just for personal performance issues that I have with it. You here to "Go Lipo" but there has to be some negative aspects associated with doing that, and info I still seek to find, before making that step...Lol..


Here is some battery info for any who don't know the diff between NiCd, NiMh, and the Lipo's...

http://h1070761.hobbyshopnow.com/pro...e=1555-ART.xml

Come to think of it, I have two Sony AAA NiMh's in my wireless mouse...Hate to have that explode, surfing RCU left-handed would be the pits...Lol..

See ya around,


-- Jeff

Here are pictures of what CAN happen to a NiMH...

man, i don't want that to happen to my dx7 - hopefully it was just a fluke and the magnetic lines or something over there combined with the bad cell and poof - just glad you're ok (imagine holding the thing and it went off like that) - i now officially treat it like a lipo and charge the pack out of the dx7 and in a lipo bag just in case, just like i do when charging everything else rc that i have - when you think about it, 2200mah is nothing to sneeze at, the 450 uses the same mah lipo


edge

You just don't want that to happen to anything i guess . This happened due to improper use (charged immensly wrong), but does show what can happen. I'm rebuilding my DX7 now, with help of my LHS guy; he has GIVEN me a 2000mAh NiMH and some electronics cleaning stuff to start rebuilding. And YES, i WILL charge it in the proper manor now . I'm now charging the new pack, but also in a metal case, just to be sure. Also charging on 1/20th of the capacity... Cleaned the inside of my DX7 with some kind of stuff. I cleaned out a lot of dust/ash which immediatelly smelled the same as when it just happened.

glad to know my radio is safe when using the supplied charger!!!

i just got all the helis finished installing ar6100's (except for 4#3 and the micron as they will need adapters for the servo plugs cause they're micro-sized - i'm not totally sure the receiver would even fit inside the canopy of either one of them after shoehorning one into the 52#3) - now i wonder if i need to back up all the data on the dx7 - is there a simple way?


edge

I'll report if my DX7 still has it's model and setup memory when i try it this afternoon... I sure do hope so! It seems the DX7 has EEPROM storage of some kind, which is able to survive quite some abuse.