LiPol-potential WMD!?  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       


Slimline Boxxer Fuel Pump
Seller:  Erick Royer
Details:   $50.00   |  9/2/2008   |  Classified Ad
We will rotate YOUR AD in this spot if you select "Forum Featured" when placing or editing your ad!

All Forums >> Radios, Batteries, Clubhouse and more >> Batteries & Chargers >> LiPol-potential WMD!?
Page: [1] 2   next >   >>  

Login
Message << Older Topic   Newer Topic >>
LiPol-potential WMD!? - 10/21/2003 1:12:50 AM   
kennydee


 

Posts: 247
Joined: 12/27/2002
From: Atlanta, GA, USA
Status: offline 		OK, I'm back, been building fanfold planes, just basic designs. In fact, I don't design anything, I just put it together until it looks right. So far, they all fly well, amazing me and my flying buddies. I'm using LiPol batteries and I can't handle the stress. I'm keep seeing warnings about these things. I'm following the basic guidelines for charging, checking single cell voltage in 2 cell packs. What I'd like to know is--what happens, should there be a major accident? I've been told they get hot and swell up and they can explode! What kind of explosion and how violent? Do they fling molten Poly all over the place? Is it a firey explosion or just hot stuff? I'm charging my LiPol cells inside an oven proof ceramic bowl, should I cover the bowl, should I wear protective gear while charging(you know, like the bomb squads wear when they de-fuse a bomb)? One person even told me a LiPol pack could expode just sitting around between uses, should there be some kind of internal break-down. Someone please clear this up for me so I don't have some kind of internal break-down.
       Post #: 1

RE: LiPol-potential WMD!? - 10/21/2003 12:57:07 PM   
Scoubidou



Posts: 1547
Joined: 7/7/2003
From: Boisbriand, QC, CANADA
Status: offline 		Read that thread and look at the pic at the end.

http://www.rcgroups.com/forums/showthread.php?s=7c6fd907b0341a7785a8ac6336c0072d&threadid=152536
Scou

(in reply to kennydee)
       Post #: 2

RE: LiPol-potential WMD!? - 10/21/2003 2:58:09 PM   
elevator_up



Posts: 298
Joined: 6/3/2002
From: Wilmington, Delaware, USA
Status: offline 		This photo certainally exceeded my expectations ! Was this a fabricated explosion or is it really possible to be this explosive ?

If this is realistic, sounds like the triton temperature probe is a must have for lithium charging safety !

(in reply to kennydee)
       Post #: 3

RE: LiPol-potential WMD!? - 10/21/2003 3:54:36 PM   
nbcguy



Posts: 220
Joined: 2/13/2003
From: Jacksonville, NC, USA
Status: offline 		I can definitely understand your apprehension about the LiPo cells. I was getting all excited about super long flight times in my foam planes with reduced weight, and then I did some research and read what Dave Thacker had on Radical R/C. There just seems to be waaaaay too much to fiddle with and test when it comes to LiPo to justify the benefits at this time. At least it seems that way to me. "Never leave them charging unattended" I don't need that kind of pressure on me. I get nervous enough leaving NiCd batteries fast charging in the garage.

Eventually the LiPo technology will be great for R/C, but I think we have more work to do.

(in reply to elevator_up)
       Post #: 4

RE: LiPol-potential WMD!? - 10/21/2003 5:36:28 PM   
Scoubidou



Posts: 1547
Joined: 7/7/2003
From: Boisbriand, QC, CANADA
Status: offline 		The Li-po is the future of the R/C hobby but today they are still experimental.
You just have to look at the FMA direct website in the battery selection. You will get a big pop up warning window explaining the danger of using them. The weigh saving and longer flying time is very attractiv for all of rc planes addicted but many considaration must be taken to use. In my case, i am going to try the Li-ion form Duralite or Powerflight. The li-ion is already used in cellular phone and laptop for many years and they are light and safe.
Elevator, look at that thread for explosion details:
http://www.rcgroups.com/forums/showthread.php?s=acd4b60eb39c4c0960abab1a251637eb&threadid=151687
Scou

(in reply to kennydee)
       Post #: 5

RE: LiPol-potential WMD!? - 10/23/2003 1:02:15 AM   
elevator_up



Posts: 298
Joined: 6/3/2002
From: Wilmington, Delaware, USA
Status: offline 		OK, thanks for pointing out how dangerous these can be if not properly handled. I will have much more respect, but just as my car takes highly explosive gasoline fuel, I still use it and treat it properly. No need to be wimpy about using lithiums if you follow the proper procedures and use the proper equipment.

< Message edited by elevator_up -- 12/12/2003 5:38:49 PM >

(in reply to kennydee)
       Post #: 6

RE: LiPol-potential WMD!? - 10/23/2003 1:18:46 AM   
Panzlflyer



Posts: 1940
Joined: 2/28/2002
From: Goldsboro, NC, USA
Status: offline 		Your right on that.
BTW my cell phone (Motorola) and a lot of the new ones are using LI-Po and Not LI-Ion

(in reply to elevator_up)
       Post #: 7

RE: LiPol-potential WMD!? - 10/23/2003 3:24:10 AM   
mr.rc-cam



Posts: 536
Joined: 6/6/2002
From: West Coast, CA, USA
Status: online
quote:

No need to be wimpy about using lithiums if you follow the proper procedures and use the proper equipment.
Please keep in mind that consumer applications that use LiPo's and Li-Ions cells have sophisticated protective circuitry built into the pack and use chargers that were specifically designed for the supplied battery (no user intervention required).

In contrast, our R/C adapted Lithium packs have no protective circuitry (if it exists it is usually removed!). The chargers that we use are general purpose and so they require user intervention (charge conditions must be properly set by the human operator).

This makes a big difference when it comes to safety and requires deligence during charging and operation to prevent serious trouble. Do not under estimate the potential energy stored in these little packs!

(in reply to Panzlflyer)
       Post #: 8

RE: LiPol-potential WMD!? - 10/24/2003 11:36:19 PM   
Panzlflyer



Posts: 1940
Joined: 2/28/2002
From: Goldsboro, NC, USA
Status: offline 		Some of our packs DO have the circuitry....it depend whos camp you fall in and if you make your own.
I have not removed the circuitry from mine that have them (Made for RC use) as I have not seen a good case made for removing it ( yeh I hear the ole electronics fail all the time).
I have said this before ....I personally have seen a Lead acid explode and put a dent in the hood of a car after a cold winter morning start and my Stick caught on fire after a thumbs incident. 10 minutes later the Nimh pack was still to hot to touch and had melted down.
I guess we need to be carefull with ALL of the chemistry.
The purpose made chargers for Li are pretty cheap and idiot proof and are available at a number of places.
Check your facts before you make sweeping statements.
While you have a vaild point about taking care, scare mongering gets us nowhere.

< Message edited by andyt -- 10/24/2003 11:42:14 PM >

(in reply to mr.rc-cam)
       Post #: 9

RE: LiPol-potential WMD!? - 10/25/2003 4:00:11 PM   
kennydee


 

Posts: 247
Joined: 12/27/2002
From: Atlanta, GA, USA
Status: offline 		Hey, did somebody call me Wimpy? I hope everyone noticed that I was exaggerating for comic effect. My basic question was this--If a Li-Pol explodes, what is the worst case scenario? I'm still a little worried about the safety of these batteries. I did pick up some good hints on how to set up the battery while charging. Sounds like you need to put the batteries in a fire-proof container and well away from anything combustible. I had been using the battery in my Van to charge, I think I will reconsider that, maybe get a very long charge lead. I don't think I will purchase another Li-pol for the time being.

(in reply to Panzlflyer)
       Post #: 10

RE: LiPol-potential WMD!? - 10/25/2003 5:46:12 PM   
mr.rc-cam



Posts: 536
Joined: 6/6/2002
From: West Coast, CA, USA
Status: online
quote:

...I have not seen a good case made for removing it

In the e-flight R/C app, the protective circuitry affects performance. Also, indoor eflight modelers remove it to reduce weight.

The Li-Po/Li-Ion Rx and Tx packs that are commercially sold are available with protective circuitry (i.e., Duralites) . But my responses pertain to the e-flight app, which is what the thread author's app is about. I have yet to see any use of the protective circuitry in an e-flight pack. As things evolve this may change (perhaps it already has).

quote:

While you have a vaild point about taking care, scare mongering gets us nowhere.

Hmm. I do not aim to be a scare monger. Calling my comments that is a bit silly.

< Message edited by mr.rc-cam-RCU -- 10/25/2003 10:26:47 AM >

(in reply to kennydee)
       Post #: 11

RE: LiPol-potential WMD!? - 10/25/2003 9:08:17 PM   
Panzlflyer



Posts: 1940
Joined: 2/28/2002
From: Goldsboro, NC, USA
Status: offline 		The scare mongering comment is aimed at the this persistent topic of fires and explosions and not you alone..sorry
If people insist on NOT reading the instructions and the battery blows up is that a good reason to stop using it?
The example in the video was a battery pushed to extreme and I believe that you would get some similar results from massivly overcharging other types as well.

Fma and such are going to cover their rears with warnings in this day and age.
Look how many warning stickers are on everything.

There are people on this forum who are still arguing about Nimh batteries.

The protective circuitry is only on the Input/Charging side to prevent overcharging.
The output side is not protected and you can pull out as much as you want.

Kokam and such make dedicated chargers that are pretty cheap compared to the Nicad/Nimh peakers.

(in reply to mr.rc-cam)
       Post #: 12

RE: LiPol-potential WMD!? - 10/25/2003 9:23:44 PM   
mr.rc-cam



Posts: 536
Joined: 6/6/2002
From: West Coast, CA, USA
Status: online 		I agree with you that there is no reason to stop using the batteries because of the reported problems. The issue is that R/C modelers must be extra careful with high-capacity batteries (regardless of chemistry). These sort of discussions help reinforce that.

There are quite a few fire stories involving Li-Po's and LI-Ions on the various R/C forums. Many are from experienced modelers. This one really got my attention: http://www.rcgroups.com/forums/showthread.php?s=&threadid=140641

I use Li-Po's. So, I certainly am not saying that they should be banned. But they do concern me enough that I treat them with extra care.

(in reply to Panzlflyer)
       Post #: 13

RE: LiPol-potential WMD!? - 10/25/2003 11:02:18 PM   
rclooney