Lipo Battery Bunker

by FliteTest | June 19, 2014 | (27) Posted in How To

Lipo fires are a real thing and it's important to take precautions when charging batteries at home.Team BlackSheep have a great Lipo Pouch available.HK-010 Power Analyzer is a great tool for testing your batteries.Common sand is the best way to put out a Lipo fire.This battery bunker is made with 6 cinder block and a sheet of cement board. We chose to put the charger inside to have the ability to charge with the balance connector.Our battery bunker has a smoke detector attached to the cover to alert us if a fire occurs.Utah Flyers Organization has some great information and videos available for Lipo battery safety.Placing the battery in the channel, if the battery catches fire the sand will extinguish the fire.Here's a great article covering details about making an old ammo box into a charging station.These ammo boxes are an option for carrying and transporting your batteries. 

COMMENTS

surfingman1 on June 19, 2014
To save your charger you could make the charging and balancing leads longer. This way you only sacrifice the bad battery.
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Nathan_116 on June 19, 2014
That's what I was thinking!!!!
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Oldmiamicrasher on June 19, 2014
Great suggestion.!!!!!!!!!!!!!!!!!
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scottdnc on June 19, 2014
You guys are the best!!! I was just thinking about battery safety this morning. It just hit me that I've built up a huge collection of batteries with single cell through 6 cell and was wondering what's the best way to handle them. I have a small refrigerator that I use to store charged batteries that I don't use on flying day. I use the "storage" setting on my chargers to take my used batteries to 50%. I think I'll build a bunker to store those batteries and another one to charge them. Are the batteries in the small fridge safe? They're the only thing in the fridge (I keep them in zip lock bags for moisture considerations).

Thanks again for all the help. Flite Test is my "go to" source for information.
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Huggs on June 20, 2014
My son and I each got one of these -
http://www.amazon.com/gp/product/B008HZUI2A/ref=ox_ya_os_product_refresh_T1
It's hot pink for BCA and was under $20 last month.
It has a latch with a key and a nice handle.
So far I'm very happy with it.
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wilanz on June 24, 2014
This is my first FT Build! Just went to home depot and the clerk told me their sales rep showed up with a flame torch to show them how good the cement board was against fire. Clerk helped me cut it in half to fit in my car (since car was full of planes). Now I have my mini bunker(only 4 blocks instead of 6). Wife will be very happy to hear about this since one of the local guys just burned his car (console, seats and interior charging batteries inside his car with an inverter).

I have some spare cement board. I plan on making a couple of mini boxes for field charging. Something that will hold the battery instead of an entire charging station would be nice.

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rcspaceflight on July 3, 2014
Great episode. This has inspired me to move my battery charger to the garage. Actually, since I have a newish car battery I don't need, I'm going to switch to solar. I'm going to buy some more Turnigy Accucell-6 chargers and using the car battery means I don't need to buy any more power adapters. Just a solar panel to charge the car battery.

A landscaper dumps his waste at my dad's farm so I have stacks of busted bricks for free. I'm sure I'll get a bunker built out of it. ;) Can't beat free.
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jetpackninja on June 19, 2014
Excellent. I hope that this will encourage more people to move their charging operations out of doors. I have moved mine outside. And all of my field charging is now done on the tailgate instead of the engine compartment. A couple of cinderblocks with a paver on top makes a great storage bunker in the garage.

Josh- The salt water method is not a relaible way to discharge lipo batteries.
Best to hook up to a 12v light bulb and make sure the battery is totally drained.
Do this with care (outside, fire safe location), as the battery drops below it's safe charge, it may puff, if it is compromised it may burst.
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Nathan_116 on June 19, 2014
Could you post a link to the ammo box you guys bought at Walmart. The closest army surplus store is 30min away, and since I can't drive yet, I think my mom would appreciate going 5 min down the road to Walmart.

Also, do you hav to worry as much if you only have a charger that uses the balance lead like the $10 hobbyking charger?
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shermanhartman on June 19, 2014
Personaly, i wouldnt get an ammo can from walmart. Get a good metal one. If you dont want to drive out to a surplus store, order one online. I use a 50 cal can and all i did was remove the seals from the lid.
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Nathan_116 on June 21, 2014
Do you think that a Metal cash/money box would do the same thing? They sell them at Walmart and you can usually get then for less then $20, and there are plenty of sizes to choose from.
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rccollecter on June 19, 2014
I heard a little bit about the LiPo fires but didn't think they were a big deal until a pilot at my local airfield talked about them. I have LiPo safe bags and I take caution when I charge them now.
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sailorJohn on June 19, 2014
It seem certain batteries puff worse than others. My ammo box has a rubber seal making it airtight and worries me that if a battery did flash fire it might be like a firecracker in a mailbox (I was the victim)
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jayman72 on June 19, 2014
I thought the same. Few weeks ago i bought 20 x ammo boxes. Thinking about removing the rubber seal to have a bleed point. They sit on a steel shelf in the garage.
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shermanhartman on June 19, 2014
When i made mine, i cut the seal on the 2 long sides, but left it on the ends, so the lid still fits right, but it also vents.

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sailorJohn on June 22, 2014
Leaving part of the seal--Good tip -- thx!
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Flynn on June 20, 2014
I have a question about storage. How do you guys store your batteries? In the summer, I have charged batteries stored in my lipo bags. Would a bunker be good for storage or is the ammo can a better way to store them. I should also add that I store my batteries in the garage not outside.
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jetpackninja on June 20, 2014
Bunker, bunker bunker ;)
Ammo can, OK. Bunker is better.
I don't think you can beat a cinderblock with a bag of sand on it.
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1959cutter on June 19, 2014
was that josh snoring at the end????
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shermanhartman on June 19, 2014
So, does a class C fire extinguisher work on lipos at all?
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pressalltheknobs on July 10, 2015
A lipo fire is not an electrical fire as such. It's a chemical fire. The break down reaction in lipo is self sustaining so containment is the best solution. Fire extinguisher are not effective. You basically have to wait for it to finish reacting. A common household class ABC dry fire extinguisher is helpful to put out any secondary fires that the lipo may light and should be on hand in case the containment fails. A CO2 fire extinguisher might be useful to cool a loose battery or a battery in a model enough that it can be moved to a safer location but its effects are temporary. If the failure occurs while you are charging then electricity is involved so using a water based fire extinguisher is a very bad move since you may create an additional shock hazard. A water based fire extinguisher may be a bad idea anyway since the moisture may make the reaction worse.

After ensuring personal safety, the first thing is to disconnect the power. The second is to ensure that the failing battery is not close to anything that can easily catch fire and if possible move that stuff out of the way. The third is to try and contain it until the reaction stops. Opinions seem to vary about how toxic the fumes are but you want to avoid inhaling them.

It is not clear that sand is the "best way to put out a lipo fire" as the article states. There seem to be different opinions and it could actually be dangerous. At best it is a way to contain the reaction after that fact and stop it from igniting the surroundings but the sand should be dry and you need enough of it to cover the battery with a good heavy layer. At worst the moisture in the sand may react with the failing lipo and make the reaction more intense. Sand will not contain the fumes.

Assuming the battery is disconnected from any electrical power and there is a safe way to move it there seems to be good evidence that putting it a large amount of water will effectively contain the reaction and absorb most of the fumes. The cooling effect of the water may prevent the reaction from igniting other cells in the pack. How large an amount of water is sufficient is unclear but it needs to be enough that it can absorb any increase in the vigor of the reaction and not boil. Having a 50 gallon oil drum full of water for this purpose at a flying field might be useful. Without further quantification it seems too risky to attempt with anything you might have handy at home.
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Scott594 on June 24, 2014
Nice miniature smoke detector - want to share the source?

I think it's time.
I have several metal "safeboxes" I keep batteries in, and a couple silver bags for charging. Been shifting batteries from cash box, to lunch box, to tool box. Bag full of indoor flyer (1S240ish) batteries so I can't charge in it etc. It's been gradually de-evolving as my collection grows and I fly more. I now have 3 chargers (all balancing - I won't compormise on that), probably 50 batteries if you add them all up. And a Ground station with a gawdawful load (8+) of 4S 3700s. Sooner or later, I'm going to screw up and I know it.

Last batch of batteries in, I started a Works Database coding each battery as to Cells, size, and serial number - 3S30-1000-27 is a 1000mah 3S 30c battery and it's my 27th battery. I got a Brother labelmaker at the wholesale store, and it works great on batteries and wiring harnesses. I also mark them with max, min, and stop using voltages. In the data base I note anything bad like crashes, excessive discharge etc. and try to keep track of the approximate number of cycles on it.
I believe ORGANIZATION (can't believe I'm uttering the "WORD") is the key. For me anyway. The bunker will force me not to cheat, and "just charge a couple in on the kitchen table" on the way out. If I make a workstation, I'll use it.
Thanks for a sane approach to a subject people like to go insane over. Nice Video.
Scott
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JasonL on June 19, 2014
Great advice! I have some spare cinder blocks laying around. Looks like I have another weekend project! And LOL at the snoring battery at the end.
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StndbyHD on June 20, 2014
Does anybody else realize what's sitting behind them on the wall parkzone su-29mm how did you guys get one so early? I can't wait till the 28th to go pick one up. Also I will be using an ammo can and a lipo bag from now on not worth burning down the garage or melting my car battery.
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Huggs on June 20, 2014
I noticed that they still have them for under $20, but not the Hot Pink.
Hot Pink is of course only for men who are secure in their masculinity..... (c8
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lysle42 on June 20, 2014
lots of old bbq grills out there and they are great for this, I store my good ready batts in my good gril (when not cooking on it) and charge batts in old grill. plus fun to have at the fly field.
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marc60 on June 21, 2014
I use 2 biscuit tins; a smaller that I put in a slightly bigger one. Bought them for 2 euro each. So kinda double hull, very cheap. Bopught two set, one for empty and one for charged


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mikewheel on April 28, 2015
I just made one. I hesitate to close the front.... I don't want my chargers to become too hot.
There is the picture : https://drive.google.com/file/d/0B4bI_slD1QrsX1hPWTVBUGlzMXc/view?usp=sharing
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dmlong on May 19, 2016
What type of power supply and charger was that in the video?
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FractalBuddha on November 25, 2017
I made my own Lipo Bunker. I wanted something portable, that extinguish flames and with the charger outside. I tested it and it worked well. I made some modifications after my test. I divided my bag.

https://youtu.be/s0kzuEpyNyQ
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Lipo Battery Bunker