Safe Battery Charging Bag - didn't know this existed

zespectre

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Apparently with the heavy use of LIPO batteries for the RC hobby realm, various companies have started producing "Charging bags" to increase safety against explosions or thermal runaway burnouts. I had no idea such a thing existed so I thought I'd pass that information along in case anyone cares.

Example of testing a bag...
https://www.youtube.com/watch?v=hcwOwf55Rtc

Example for sale (not endorsing this item, just showing an example)
LIPO SAFE for charging
 

milehigher

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These grew out of the issues with exploding case's hover boards and Samsung products first popularized by air carriers having special containers for cargo , and now in most cabin areas there are kits in several areas of the plane with nomex aramid gauntlet gloves a hood and face shield and a bag so with gloves and hood donned you can toss a runaway battery containg device into it and it will contain it long enough to declare an inflight emergency and get on the ground , but like with anything someone saw a chance to make some money so they are being marketed and sold to consumers wiith different configurations, for our flahlights , phone models, drone power modules , just to name a few , the reality of it though is its to late , because its well known do not buy junk batteries and god knows who chargers , thats the key with proper cycles of charge/ discharge ,and not abusing the batteries or pushing them beyond spec frequently should need a bag.
 
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KITROBASKIN

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Radio controlled car racing may be one of the earliest hobbies where batteries were being over charged so the cars take off as fast as possible, and things would go very wrong.
 

degarb

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I believe in triple redundancy with everything. So, I only use protected Panasonics, charged by smart charger in tins, with multimeter to measure off charger. Then I tote my headlamp around in bookbag, inside cookie tins.

I did buy a lipo bag, was able to instantly punch through the apparent fiberglass with blow torch. The outside bag shell is flammable plastic. So, i would feel more comfortable taking 2 layers of fiberglass, sandwich fireproofed borate caulking, and industrial staple my own bag together. Borate treated caulk laden fiberglass does quite well against a blow torch. Fiberglass alone resists a butane lighter, but not a plumbing blow torch.... I didn't go this route, opted for tin containers for my headlamps, since they benefit from the crush protection...

Now, still unsure of how much protection a good steel/aluminum flashlight tube will offer a user, if a cell blows from overcharge or flames from short. All youtube explosions or flameouts videos happened outside a good aluminum tube light. Overcharging, it blows, but shorted, it is a roman candle.

Though, for the plethora of cell phones and tablets in my house, using nothing more than the built-in protection circuits, and faith no shortcuts were made. Insanity, really.
 
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Gauss163

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[...] Though, for the plethora of cell phones and tablets in my house, using nothing more than the built-in protection circuits, and faith no shortcuts were made. Insanity, really.

But there is much more than just protection circuits. Cellphone, tablets, and laptops generally have far more safe battery subsystems than devices that use external universal Li-ion chargers. The safety of universal chargers is limited by the fact that they know nothing about the cell - such as its max charge rate, chemistry, IR & temperature profile, etc. But all of this info and more is known for the specific battery used in a cellphone or laptop. The integrated dedicated charger can communicate with the BMS and use this information to ensure that (dis)charging is always safe, even when the battery ages and IR increases (e.g. recent iPhone throttling). In some cases by tracking the health they can even detect impending internal shorts (e.g. heuristic enhancements to TI's impedance tracking algorithms that I mentioned before). This is difficult if not impossible for devices using external universal chargers since they generally don't have access to the necessary information.
 
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zespectre

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Personally my nod to safety is that I bought a few 8" ceramic floor tiles at lowes. One in the bedroom, one in the office, one down in my workshop. Anything I'm charging sits on one of those.
 

degarb

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But there is much more than just protection circuits. Cellphone, tablets, and laptops generally have far more safe battery subsystems than devices that use external universal Li-ion chargers. The safety of universal chargers is limited by the fact that they know nothing about the cell - such as its max charge rate, chemistry, IR & temperature profile, etc. But all of this info and more is known for the specific battery used in a cellphone or laptop. The integrated dedicated charger can communicate with the BMS and use this information to ensure that (dis)charging is always safe, even when the battery ages and IR increases (e.g. recent iPhone throttling). In some cases by tracking the health they can even detect impending internal shorts (e.g. heuristic enhancements to TI's impedance tracking algorithms that I mentioned before). This is difficult if not impossible for devices using external universal chargers since they generally don't have access to the necessary information.

In theory, yes. But, we are talking about many manufacturers. None published which protections are implemented.
 

Gauss163

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In theory, yes. But, we are talking about many manufacturers. None published which protections are implemented.

No, in theory and in practice, e.g. there are hundreds of pages of international safety standards for laptop batteries, and rigorous safety testing using industry standard methods (fault-tree analysis, FMEA, etc). None of this exists for standalone universal chargers.
 

BVH

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Not all Lipo bags are created equally. No Joking here. There's been a lot of testing on RCGroups forum and Lipo Sack brand is the one that does what it's supposed to. Others burn up and do not contain the run-away Lipo.
 
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zespectre

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Not all Lipo bags are created equally. No Joking here. There's been a lot of testing on RCGroups forum and Lipo Sack brand is the one that does what it's supposed to. Others burn up and do not contain the run-away Lipo.

Good to know. Thanks for sharing.
 

Lumineux

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Candid question : if one charges a battery inside an enclosure such as the one discussed in this thread, or in any closed space generally, does it not cause potential issues regarding the heat generated by the battery ?
 

degarb

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Personally doubt it. My Qualcomm charges extremely fast, and phone has heat insulating back.

I use cookie tins, which would heat transfer. I suppose not good for traveling.

If you don't need a high current, go protected. Always name brands. Fenix has protected cells which do short protection, over charge, under charge, and thermal. I don't believe thermal is in any of my Panasonics, or protection circuits I welded on unprotected cells using a car battery and multi meter leads.
 

Lumineux

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Personally doubt it. My Qualcomm charges extremely fast, and phone has heat insulating back.

I use cookie tins, which would heat transfer. I suppose not good for traveling.

If you don't need a high current, go protected. Always name brands. Fenix has protected cells which do short protection, over charge, under charge, and thermal. I don't believe thermal is in any of my Panasonics, or protection circuits I welded on unprotected cells using a car battery and multi meter leads.

I also transport my headlamps and 18650s in cookie tins. Fire and crush resistant.

Thank you for your input :thumbsup:

I only use AA batteries and only buy Eneloops, so risks should be quite lower than with 18650s. Still, it's always good to remained informed on potential hazards.
 

recDNA

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Does the bag have an opening for a power cord? If not how do you charge in the bag? Is it transparent? If not how do I know when charging is complete?
 

degarb

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Does the bag have an opening for a power cord? If not how do you charge in the bag? Is it transparent? If not how do I know when charging is complete?


I have watched YouTube videos on the topic of thesr bags, including them containing liion fires. They work.

My bag only lasted until I took a blow torch to it.... While they obviously work, i noted the outside is very flammable plastic, and the fiberglass empirically is only cigarette lighter proof and not blow torch proof. Fiber glass can be made blow torch proof, by adding borax to silicone caulking. Tubed silicone caulking, alas, if very flammable, until the borates are added. For more money, you can order flame proof caulking. I tested my borated caulk on aluminum and fiberglass with plumber blowtorch (butane). The insulating, borates add much resistance. Catalyzed silicone with borax should do even better, I assume. Test your mixture first.

If the standard charge bag's fiberglass were borax and silicone reinforced, and outside not flammable, I. Would feel better about them.

I still have my bag, in which, put spare 18650s (in protecting plastic carriers). But my bag now has a hole which I poked through in under a second with my blow torch. (Adding the above borated barrier probably adds 30 to 60 second, or more resistance to a direct blowtorch.)

Jet engine technology heat reinforcement on light metals that would otherwise melt, those material engineers have really cracked the problem. Why they dont apply that technology to the cargo area, then to isolate declared liions from the rest of cargo, and separate cells from each other, is beyond me.

Nevertheless, despite my personal bag design resignations, the youtube videos demonstrate them working, by real users.

There is the direct short=roman candle failure-the worst does not seem to last more than 40 seconds . Which would have one temperature.

Then there is the overcharge explosion. The temperature and physical damage result would different.

I would only go imr if they came witb over charge and under charge circuit which would drop the short protection. Relying solely on charger circuit is stupid. Triple redundancy in life. My third is cookie tin. Forth watch and testing voltage off charger to make sure the electronics are in order. So, 5 layers of protection when charging. 1. Name brand. 2. Protection circuit 3. Smart charger. 4. Cookie tin 5. Always check voltages. 6. Set timer then, you could: charge only in middle of your empty garage. 7. Fire proof garage. 8 install a fire alarm near charging area. 9. Gfci charging outlets and keep lots of ice water to cool the lithium fires 10. some F500 or metal fire class extinguisher 11. Move next door to the fire department 12. Go back to nimh, despite their inferior capacity and higher ownership cost 13. Discard nimh cause they can short too and cause fires 14. Discard your candles because fire causes fire 15. Just wear an eye patch, to let one eye be ready for the night... I am joking, but incorporate as many as are practical, if burning down your house matters.

I think the f500 can be purchased for $200 and added to water. The FAA airboyd has video how they use water on planes to put out laptop fires. F500 is utterly fascinating. If I could get it for $50, I would own some....

Fireade not sure if rated for lithium fires.
 
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degarb

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I wonder why more people aren't interested in what around them burns or not.

We are always being touted space materials, which is a good sign they are as flammable as hell itself.

Even fire resistant insulation, burns rapidly when tested on YouTube. Surprisingly, borate treated recycled blown in insulation retards actual fires.

Of course, people put up with pollution, ugly power lines, ugly roads, etc. It comes down to everything in our lives is but one long
trade offs, life by triage. Even down to your cellular level.
 
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