DavidR8

Pretty serious!

http://m.kitv.com/news/homeowner-fir...-fire/24445618

Don Sims

Hate to read about that fire. Wonder if he really had it in a bag?

fhhuber

They discoverd in the investigations of some "LiPo fires" that it actually started in the charger.

I keep my charger on a ceramic tile now.

Larry3215

It was the fireman investigator that said he uses a lipo bag. I didnt see any details on what the home owner used.

Its lucky the fireman were RC guys or the report might have been a lot more critical of lipo use.

Would be nice ti know if he was using a balancing charger and what brand, if the packs had been damaged, etc.

kyleservicetech

Yeah
Good question about whether the LiPo was being charged on a balancing charger.

Wonder if there have been ANY LiPo batteries that ignited while being charged with a quality balancing charger??

fhhuber

Not sure about batteries.. but I know of one for sure where the quality name brand charger lit up, taking out the car, LiPo and house.
The charge was being watched and the owner saw the sparks start in the charger. He still couldn't get it disconnected in time.

Turner

If he was there and watching things and still lost the house he must have been doing something very stupid.

Karnsy

I wish I could find a lipo fire proof carrying case that would hold at least a dozen or more battery packs. I currently store all mine in a lipo bag (12 to a bag). I wonder if one went bad while in storage if it would be contained with so many packs in the same bag. I take care of my packs and always keep my eyes on them but I would love to have a case that would hold them and use the bags for charging. Anyone have any ideas.

flydiver

Metal tool box, the smaller hand carry type. I've got an older Craftsman that would likely contain something like that but would be a nuisance to carry around.

kyleservicetech

I found a couple of these years ago that might do the job. Among many other locations, Sears has a few like this one:

http://www.sears.com/excel-14-in-por...&blockType=G30

dahawk

Bummer. Hate to hear that. I use a Army ammo canister. Drill vent holes in it. WTS here gave me one. Also have a $20 fireproof safe from wally-world. Keep everything in my detached garage. No cars allowed. Try to store mine at storage voltage or about 3.7 volts per cell. That's how they ship them.

kyleservicetech

Yeah, I've heard about those fire proof safes from wallyworld before. Sounds like a pretty good idea.

Beemerider

I have a question for you lipo guru's. I use a balancing charger but I only balance charge when my battery watt meter says the cells are unbalanced. Otherwise I always charge them at 1C.

So bottom line is I only occasionally balance charge. Is this ok? How does this affect battery life?

fhhuber

All balance charge does is to bring all the cells in a pack to the same voltage. if they are already within 0.02v you don't need to bother.

The main reason to balance is to prevent the high cell from going above 4.2v and the low cell from going below 3.2 v.
Somewhere above 4.25v the cell will burn. usually above 4.30v, sometimes almost 5.0, but anything above 4.2 is risky.
Somewhere below 3.2v the cell will be damaged and become dangerous to charge at all.

kyleservicetech

Good question

As for me, I always balance charge, even with those A123 cells. Can't hurt, and seems to me with LiPo batteries, balance charging would really reduce the chances of catastrophic failure during the charging process.

Beemerider

I generally only balance charge when at home since in longer charge time is not an issue. At the field I do a standard charge.

Thanks for the additional info!

kyleservicetech

Yup
That's why I use those over weight, under voltage, heavier A123 cells. All of my 300 watt or larger models use them, and they are balance charged with the Cellpro Powerlab 8 chargers in about 15 minutes.

In fact, my giant scale models with 12S2P A123's are charged as a 6S4P pack with a charging rate of 30 Amps. The 6S2P A123's in my 1 KW sized models are being charged at 20 Amps, about 5C. They don't even get warm doing this.

Those chargers are pulling about 55 Amps out of the 12 Volt DC source, but that is another story! (Note, big deep cycle Lead Acid Batteries can't do it, not and last very long anyhow)

Turner

It's fine, I do the same, but always charge with the balance wire connected to maintain all the chargers overcharge protections. This ensures that the charge will end without any cell exceeding 4.2 volts.

Karnsy

I like the tool box idea kyleservicetech. Cheap and serves the purpose. I assume you did not drill any holes in it as it can't be airtight as is. I think I will pick one up at Sears today. Here in Maine keeping them out in the garage seems like a pain in sub zero weather so I think I will keep them in the basement on the cement floor.
I still wish someone would make a fireproof lipo carrying case. One that would have individual pockets for each pack (or not) and a handle. Hey ,,,,maybe I should invent one

Turner

Common Sense Rc has a variety of them. I have the one at the bottom of this page.

https://www.commonsenserc.com/index....pnakovmhggddb4

Karnsy

Hey that's the ticket Turner ! looks like they are sold out for a while but I am very interested in that one. Looks like just what I was looking for.
I can't imagine having a fire while they are in storage but seems like this would be as safe as one could get if one did take off. Thanks for all the help !!!!

Beemerider

I had originally thought you only needed to connect the balance plug while balance charging. I appreciate you pointing that out to me. I will do that going forward now.

kyleservicetech

Yup

When first starting out with those A123 cells pulled out of the Dewalt 36 Volt battery packs, I was charging them with a home made 10 Amp charger that matched the required final 21.6 Volts DC maximum charge voltage on my 6S2P A123 packs. Balancing at the end of the day was done with one of those Astroflight little blinky balancers.

Worked fairly well. So I thought. Those Little Blinky balancers were not worth their weight in . After a few months, the A123 pack was so far out of balance that one pair of the two parallel connected cells went by by, after hitting some 6 Volts DC. While the other cells were still at 3.3 VDC.

Had to replace the two cells. That pack still works as good as new, some six years and many hundreds of flights later.

Those A123 cells can not ignite due to overcharging or similar. Had that been a 6S LiPo, it might have had a very different end result.

BillDeLong

pretty scary stuff... I wonder if he was charging the LiPo in NiMh mode???