Bigedmond

iTrader: (20)

I will never buy a Lipo sack. I understand what they are for, and why people need them. The thing is, if you pay attention and charge the batteries the way your are suppose to. You will never have the problem.

The link above, clearly a fire caused by the user. Why in world would you charge a lipo on NiMH mode and walk away? what the hell was he thinking? If you need to bring the pack back, STAY WITH IT!!!!

Most of the videos showing a Lipo fire are staged. They tell you they are because they want to show you want can happen if you screw up.

Fires in cars are because the pack gets punchered.


How many people here are seen a NiHM battery loose a cell? I saw one go at the track once. Poor guy was peaking his battery in his 10th buggy. Everyone was just sitting around and BOOOOOM. No more NiHM pack, no more car. 1 cell blowing took broke the chassis in multiple pieces, destroyed the ESC and damaged the case to the Receiver.

Dave H

There have been reported incidents, however rare, of packs that went off while in storage. Perhaps they were damaged in use and the damage was not noted, hard to be sure in these cases.

Razathorn

iTrader: (2)

This is what I'm say'n. Packs that start to puff in storage after use are dangerous. I had one start to balloon up in a hard case, and if in the course of ballooning up, it punctures itself on say a solder joint, bam -- fire. This pack was fine when I put it in storage in my ammo box... it had sat for weeks before starting to puff and stink, all while voltage was perfectly fine for storage. I'm guessing it became compromised during a race in my 1/8 electric as it was releasing all sorts of nasty smells as it puffed, which means one of the cells was punctured, and of course, a punctured cell is a time bomb waiting to go off.

Let us not forget that laptops and cell phones DO go off like road flares too, but these devices tend to not be involved in the constant abuse of model racing so they tend to not be compromised nearly as often or easily. Lipo's in RC go off because we abuse the heck out of them compared to other applications. I mean passenger cars rarely have their fuel tanks burst into flames, but you still have to wear a fire suit when racing full size cars because they do, and the chances are greater -- far greater -- when racing.

http://computer.howstuffworks.com/dell-battery-fire.htm

Dredd

So what do we think, lipo bag and charge it inside my ammo can? Store it in the bag and also inside my ammo can with the lid down but not sealed? Sound safe enough?

Razathorn

iTrader: (2)

The nice thing about lipo vs nimh is they release their energy slowly over time compared to a nimh bomb. All you need to do is shield things from the flames while you release the pressure. Charging in a lipo sack or in an ammo box is fine. The sack will release pressure, and just sitting the lid on the ammo box will cause it to lift if one goes. You don't need to do one in the other.


Store in which ever you like. The concept is simple: These things will probably never go off on you, but in case they do, they need to be in a fire resistant thing for a few seconds while they go nanners, but said thing needs to not be sealed so pressure can come out.

kcobra

iTrader: (11)

Never say never. Equipment can short out or whatever. I had a charger short out during the middle of a charge and start delivering the full power from the power supply (30 amps in my case) to the battery. Luckily for me I was parallel charging two 5000 mah packs so it was only doing 3c. Might not have been good if I was charging a single pack.

The difference is that while an exploding NIMH cell might injure someone when it blows it is far less likely to start a fire compared with a lipo that goes up in smoke.

el_Fernando

iTrader: (6)

I use a Lipo sack and when I charge the batts I have them set on a some tiles instead of just on the wooden table. Just precautionary. It's really not a hassle at all and I'm not worried or paranoid of Lipo fire. Just a little safe is all.

klaymon

iTrader: (71)

I always store in the LiPo sack and I set the whole sack in an open ammo box (lid not latched). Necessary? Maybe not, but it's peace of mind.

wingracer

iTrader: (24)

Don't waste your money to go to an IFMAR worlds then. They don't care how far you came or how much money you spent, they will exclude you from the event.

Dredd

Ounds like that's what I am gonna do as well. I can order more boxes from barret this evening. One last thing. Should I discharge my lipo if I am not sure I am gonna use t the next day. I know they hold charge well but is it safer or better in any way to discharge it to 3.8v per cell like they say is good for long term storage? Sometimes the weather in south florida is poor for days at a time and you never know if tomorrow will be good or not.

klaymon

iTrader: (71)

I always discharge to about 3.7V/cell when in storage.

Bigedmond

iTrader: (20)

Yea, having a small bomb is not nearly as important as a fire starter.

Dredd

what is considered storage? I know like if I'm not running for months but...like a few days? even overnight?

Ferenczy36

iTrader: (9)

Lipo sacks are mandatory at my local tracks which is completely unstandable in terms of insurance. I can bet that pretty soon here, any local track operator who carries insurance will be enforcing Lipo bag rules.

Dave H

Ideally the less time sitting at full charge the better.

Be aware that charge state is impacted by temperature. If you do leave a fully charged pack at the very least don’t allow it to get hotter, that’s not good. For example don't charge then leave it a car out in the hot sun.

One thing you can do if you have a charger that has a fast charge or percentage charge option, is charge to 90% or so if you are charging ahead of time. You only give up a little run time on your first run.