Lipo Box Bunker Smoke Evac Temp and charging

[Alan 3D]

I have a lot of batteries of many sizes up to 7s 5000mah Lipos.

I've done the Ammo cans and tool boxes lined with drywall. Thin drywall preferred. With thick partitions and individual drywall covers with handles.

Also use discarded unused portable barbecue grill cover and putting Tin cans inside to separate batteries. This method also works in tool boxes. Need vent holes. No sealed containers like Ammo cans which are not made to contain fire. (Must be vented).


Bad Lipo containers

Anything that burns is bad.

Anything made from ceramic or porcelain or glass is considered a bad lipo container because it can break under heat with sharp edges. I found out the hard way after a test lipo fire in a very heavy and large ceramic flower pot that had no cover, was completely vented. Broke up into pieces from the heat. Cut myself after cleaning up.

Tile has been used to protect surface but then again if you have to protect that surface why is your batteries there to begin with? I find drywall is more effective and the most heat resistant and cheap. I have used tile on some surfaces that I'm not too concerned about and I don't do lipo charging there anyways. Just to charge my transmitters which are the only things I charge indoors.


Charging station

My outside charging station is a table l made from wood but completely covered with drywall on top preventing any chance of fire. And it's outside on balcony surrounded by concrete walls only requiring one leg with the table attached to the corner wall. Doubles as a Tool storage location underneath. 47 inch high. Maybe too high for short people. Gets my eyes closer to the batteries and chargers and not having to bend over or get on my knees.

[Alan 3D]

Bunkers

Some have used the cinder block method and even use sandbags on top which would be good to help suppress a lipo fire.

Very bulky but effective. Not for portability.

Some have used the bat safe which has some smoke filtering. Expensive and not enough for my situation. Also lipo bags which I have one and almost never use. Okay for small batteries but I still want some protection from physical shock with a protective container especially in transport.


As my LiPo battery inventory increased I look to consolidate and shrink the size of the storage area which is not easy to do when your battery inventory keeps increasing. I would think going vertical is the most efficient way to go. I have gotten some brand new but discarded wire hanging shelving for pantry which I use in my closet but not yet for lipos. Perfect for tin cans. Not like traditional shelving that is much wider and deeper heavier taking up considerable space. I hung one on the back of a closet door and another on the wall in a closet. Looks beautiful and can't beat the cost of free.


Portability

For lightweight purposes I have gone a simpler route using discarded large rectangular pan like trays for portability and using my own discarded Tin cans from food. Each individual battery has its own container. Small cans for small batteries and large cans for large batteries.

Using two cans per battery, one can acting as cover, the other fitting inside.

Each battery having its own container to reduce the chances of a chain reaction. No batteries actually touching one another. Only small batteries share the same container. Sometimes putting them in plastic sandwich bags especially those that don't get used that often. I have multiple sizes. No problem fitting a 7s 5000 25c battery.

If you want to go super large, go with the cracker cans which I do not use. Or at least not yet. Three to four cans can fit inside one of those large cans which also could be enough room for a sandbag.


My Bunker containers

All my batteries I keep outside 24/7.

Currently I'm using a discarded industrial size sink stainless steel. I sometimes put other large trays on top still have plenty of ventilation.

Still also using Ammo cans and Tool boxes also. Any battery that has any issues like puffing, mishapened or slight physical damage or has balancing problems are normally discarded but for me having the batteries outside are quarantined away from the other batteries in their own separate toolbox containers that are petitioned and with individual covers insulating one battery from the other. Any bad batteries with physical damage or very high internal resistance should be discharged and destroyed. Any cells that are at or near zero volts are either removed from the pack or battery is disposed of. Most people completely discharge and discard damaged or puffy batteries which if kept indoors is an absolute must. My batteries are never inside especially when charging. Batteries can catch fire at just about any state of charge including storage charge. Lipo fires are most common when charging. Second is during or after a crash. Consider putting the battery in quarantine if not discharging and disposing of. And third would be just sitting around fully charged. Then last at storage charge which is far less common but does happen.



My objective

Fire Resistant

Smoke evacuation

Isolate and Quarantine

Outside storage area

In case one battery should go up in flames there will not be a chain reaction from One battery to the others causing massive fire and smoke which is outside on my balcony which has ventilation and storm shutters but will not be shuttered after reconstruction. It will be completely open. So there will be ample ventilation and less risk of smoke damage inside depending on which direction the wind is blowing. I had sprayed a extremely strong Orange air freshener they're just to determine how much smoke would come indoors if wind was blowing from that direction. Living in a building with neighbors just feet away is more critical. Still the potential for smoke damage is there. That is the reasoning for separating the batteries in their own separate container to a degree and reducing the smoke and fire. The more battery separation requires more space. Sometimes I use empty cans just to separate the batteries in other cans or just to take up space to keep things from moving around. More helpful when traveling with lipos.

[Alan 3D]

Damaged Lipo

I do have more than one battery that has an issue with it and one of them is it does not want to balance unless you charge it at half C. I have a few other batteries that have puffing or some physical damage. Normally these batteries should be discharged and discarded. Never indoors. These batteries are kept in their individual compartments separate from the others quarantined and kept outside especially when charging.

[Alan 3D]

Lipo in Vehicle

My car is never in direct sunlight when batteries are inside vehicle and they never get hotter than after a flight. One door at least wide open at field at all times. I have a trunk so the valuables can be locked in there. Maybe a problem for other vehicles having door open. Vehicle must be in shade if no ventilation.

[Alan 3D]

Smoke

The Lipo smoke alone is lethal and yes people do die from lipo fires. Very common with e-bikes and electric scooters. Hybrids are worse than gas vehicles but the e-vehicles are the least apped to catch fire except for when they end up in water and then removed from water. Water is one of the enemies of lipos. LiPO batteries can burn red hot underwater. Water does not put out lipo battery fires but can be used to put out other materials that may catch fire.

In my opinion, storing or charging lipos indoors where it can do the most damage is not acceptable. But many do just that.


Smoke and Fire damage

I know somebody personally who had a lipo fire in their home while they were sleeping. His family was awoken by smoke alarm. He no longer keeps his batteries indoors. I also met somebody whose vehicle was damaged from lipo fire. Local hobby store had a brand new battery still in its packaging go up in flames on the shelf, never charged.


Smoke evac

I have also made diagrams of smoke evac system for those who have their battery stored indoors. The idea is to evac the smoke outside. Batteries would be in a large fireproof compartment / container with a blower motor sucking or blowing out the smoke. Again separating the batteries as much as possible with their own containers even with petitioned compartments for more separation and covers inside the main bunker protecting individual or groups of batteries. Drywall probably the most cheapest material for fireproofing. Needs air inlet which comes from either inside or preferably outside. The idea is to minimize or eliminate the damage which is massive just from the smoke itself. Just containing the fire is not enough. I have done lipo fire test and found that just one battery that burns produces a ridiculous amount of smoke and toxic fumes depending on size of battery. A bunch of batteries going up at once would be devastating, smoke damage will destroy the interior of home and that's assuming the fire is contained and does not spread. Got to reduce the chain reaction chances by removing the heat and smoke associated with a lipo fire in a battery bunker. All batteries sealed in one container with little or no ventilation means they are all going up in flames together. For me, even if there is no damage to the property, the replacement cost of my batteries is something I probably wouldn't even consider. That could be the end of it.


Evac fan

The Smoke evac system has to be able to handle the heat. A fan that blows air into a container maybe more survivable than a fan that sucks out the air which is going to be heated up to hundreds and sometimes thousands of degrees. Blowing air into bunker would require a system where the smoke is not leaking out of the container, box or compartment unless that leaking smoke is also blown out with either a second fan or sucked from the air intake of the first fan requiring a supply of air intake. Again drywal and joint compoundl is one of the cheaper fire resistant materials. If you build a closet you could even use metal studs. No wood for trim and doors. Need ventilation or fan controlled with smoke or heat detection.

[Alan 3D]

Battery temperature

Some pilots do worry about temperatures but you can control temperature if preferred whether it's a combination of insulation and other means, cooling or heating or both but the main thing is not charging or using batteries when they're cold. Ideal low charging LiPo core temperature is 65° f. The minimum would be 50°f with some noticeable loss of performance. Anything lower than that you would have to take special precautions. Lower charge rates and voltages. Easier just to heat them up.

LiPO batteries are rated to handle 140° f. I don't recommend it. Charging temperature could be as high as 122° f. This temperature feels warm in the hands. A battery that is too hot to hold comfortably is a battery that is too hot. 150f Plus. Any hotter and you may have a fire.


My batteries are stored year-round outside in temperatures in the 40s to low 90s° f. On my shuttered but vented balcony protected from moisture.

I've had batteries last as long as 10 years with some loss of capacity. Depending on usage.

[Alan 3D]

Charging

My batteries are charged just before going to feild. I keep charged batteries separate from the others for obvious reasons including keeping track of them. Making sure they don't stay charged for too long. A week fully charged outside is the max for me, almost never happens. Never keep a fully charged batteries indoors ever.


Cold Lipo

Cold weather is an issue especially when your batteries have been sitting in the cold for many hours and need to be warmed up to at least 65°f core temperature for good performance and to prevent damage. Something I almost never have to do. I don't go flying when it's cold.


Parallel and unbalanced charge

One thing I don't do anymore is parallel charge because if there's something wrong with one battery it could screw up or damage the others.

I have many chargers that I can charge 10 batteries at one time while making and eating breakfast before going to the field keeping track of what's going on in the process. Very important.

Charging one battery at a time could take a ridiculous amount of time. You want to get it done and you want to keep an eye on it sometimes catching issues that come up during charging, most common battery balance lead failures. Luckily no fires so far in 16 years of using lipos. knock on wood. Only my cell phone battery puffed up so big the case and cover came off but no fire just heat.

There are some who are more lax about Lipo batteries. I've seen first hand what they can do so I am cautious. Giving no chance of a lipo fire indoors where it can do the most damage.


Unbalanced Charging

One of the worst thing you could do besides putting a nail through a lipo is unbalanced charging. Unbalanced charging is when there's no balance lead connected to charger or the charger uses a setting called unbalanced charging. I actually have three chargers that has a feature that you can actually select it which is really a bad idea and some people had paid a really big price for doing that. Fires often result. The only reason why anybody would even consider doing on balance charging is because there's something wrong with the battery to begin with and it will not or it is very hard to balance. Or at least take a long time to do so which is common.

These batteries I considered a risk which for most may mean discharging and disposing the batteries that are considered at risk for whatever reason.


Mistakes

You charge batteries enough and you can make a mistake. I charge many different batteries of size and types and cell counts.

One mistake I made was accidentally charging on nicad settings where I put on a 6s lipo on the charger and selected charge not realizing it was on the wrong setting. Its a older charger and did not care that the balance lead was connected. I came back later to find the battery was charging the cells at 4.33 volts at 4 amps. I immediately stopped charging and discharged it back down to 4.2 volts per cell. Close call. It would have kept on charging until it went up in flames.


Fast storage charge
A quick method for storage charge is at link below.

https://www.hobbysquawk.com/forum/electronics-and-rc-accessories/power-system-components/359624-fast-storage-voltage-and-discharge-options

[Alan 3D]

Opinions

They're going to be people who disagree with some of the things I have said here and that's fine but they're going to be those who say that lipos are safe and it's okay to keep in your home and the risks are very minimal. Like I said, one of my co pilots batteries all went up in flames in his home when they were sleeping. So I guess he was one of the unlucky ones. Also somebody told me his vehicle was damaged by a lipo fire. So those people that claims its not that common is suspect. The amount of internet postings of lipo fires is staggering.

I've even had somebody contact me from China telling me that what I was doing was bad talking about the dangers of LiPO batteries and then they proceeded to insult me in a un apropriate way. Yes there are people in the industry who are going to tell you that it is perfectly all right and safe. Just follow the rules. But then again your batteries are not in their homes and there's no risk to their families lives or property.


Good luck and be safe.