Safe Batteries Charger Box

Changchung

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Hi guys, seeing some batteries exploid when charge, and some high mah in my way I make this box just to prevent some troubles, I install a window with a 1cm polycarbonate (Lexan) to see inside with a 5mm Led pcb 12 volts, 2 AC connectors 4 outputs total to use almost any charger inside and 2x 80mm fans which ventilates the box with fresh air, the door is not sealed, allowing air to enter...

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Male external connector
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Please MOD, feel free to move it if not belong here...
 
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infinus

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Wow, impressive handy work. You must either be charging some very shady cells or you are a very VERY careful person?

Have you personally had cells blow up on you? If so, which brand/make were they and were they in known good condition?
 

TEEJ

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The concept is good, and I am offering some observations:

Did you know Plexiglass has the same fire rating as say, wood?

If the ventilation fans are exhausting air from the box, it would at least fan the flames less than if the fans were blowing in fresh air.

Are you using an arc-fault circuit breaker, etc, to send the power INTO the box for those receptacles?

Location:
Were the night is too short... (Should be "Where", not were...if describing location)

:nana:
 

Yamabushi

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Nice. One suggestion ... if by "plexiglas" you mean acrylic plastic, you may want to replace it with polycarbonate (Lexan). I was involved in a minor explosion (not related to batteries) where all of my wounds (although minor) were from the shrapnel effect of a shattered acrylic cover plate. My polycarbonate eyeglass lenses saved my eyes.
 

infinus

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LOL..... TEEJ..... harsh dude, but funny. :party:

I just get curious sometimes on how many REPUTABLE cells have blown up when used in known good charges in safe configurations. You browse over to the subsection on blowing up batteries and they are pretty much all cheap cells, cheap chargers, serial charging configurations, etc..... and then everyone gets afraid of them?

Not to mention the myriad of other devices in our houses that use lithium ion (in generally safe setups). My laptop has 9 of them! I don't charge it in a box.

That lead me to ask the OP's experiences. I'm curious?
 

Changchung

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Wow, impressive handy work. You must either be charging some very shady cells or you are a very VERY careful person?

Have you personally had cells blow up on you? If so, which brand/make were they and were they in known good condition?

Thanks, Just trying to avoid accidents... I have no battery blow up on me... Thanks God...

Two friends have exploited some trustfire a couples of months ago, they did not take photos.

I have just 2 trustfire and hardly use them...
 

infinus

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I suspect if you stick to good cells with protection, with a good charger that monitors each cell independently, and you are prudent on cell voltage when putting anything in a serial or parallel configuration, that you'll never need this mighty box you built. But I won't diss anyone trying to be safe!
 

Changchung

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Nice. One suggestion ... if by "plexiglas" you mean acrylic plastic, you may want to replace it with polycarbonate (Lexan). I was involved in a minor explosion (not related to batteries) where all of my wounds (although minor) were from the shrapnel effect of a shattered acrylic cover plate. My polycarbonate eyeglass lenses saved my eyes.

Replace it...

LOL..... TEEJ..... harsh dude, but funny. :party:

I just get curious sometimes on how many REPUTABLE cells have blown up when used in known good charges in safe configurations. You browse over to the subsection on blowing up batteries and they are pretty much all cheap cells, cheap chargers, serial charging configurations, etc..... and then everyone gets afraid of them?

Not to mention the myriad of other devices in our houses that use lithium ion (in generally safe setups). My laptop has 9 of them! I don't charge it in a box.

That lead me to ask the OP's experiences. I'm curious?

No bad experience, I just have some time to play with tools and prevent some issue with my chargers...
 

infinus

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I wish I had your time then! My own home built projects have been on hold with no time. Definitely some nice work on the box.
 

JerryM

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Great work, but if battery charging is so risky that I need that I am going to opt out of li-on and use Eneloops.
Jerry
 

Changchung

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The concept is good, and I am offering some observations:

Did you know Plexiglass has the same fire rating as say, wood?

If the ventilation fans are exhausting air from the box, it would at least fan the flames less than if the fans were blowing in fresh air.

Are you using an arc-fault circuit breaker, etc, to send the power INTO the box for those receptacles?

Location:
Were the night is too short... (Should be "Where", not were...if describing location)

:nana:

1- Yes, I know, the window is just to watch if something is wrong to unplug the box.

2- Yes, fans are exhausting air from the box, is for keep cool inside. If something go wrong, see the first answer...

3- No yet, I thought of connecting but space is limited. If something go wrong, see the first answer...

I am going to install two switches, one for the AC power and other to the fans

Location Edit
nana.gif
Thanks

I suspect if you stick to good cells with protection, with a good charger that monitors each cell independently, and you are prudent on cell voltage when putting anything in a serial or parallel configuration, that you'll never need this mighty box you built. But I won't diss anyone trying to be safe!

Exactly...
 
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tam17

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I must admit I've chuckled a bit at first, but in fact this solution of yours is very inventive - seems you have all the bases covered. I was thinking about safe box myself, to put an end to usual four-hour shifts by the 2x18650 charger, with DMM at hand...

My cheapo version will be made up of a sand-filled pan with a metal cover to match, LOL
 

Changchung

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I must admit I've chuckled a bit at first, but in fact this solution of yours is very inventive - seems you have all the bases covered. I was thinking about safe box myself, to put an end to usual four-hour shifts by the 2x18650 charger, with DMM at hand...

My cheapo version will be made up of a sand-filled pan with a metal cover to match, LOL

Your are welcome to post it here when you build it...
 

TEEJ

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Hmmm, Answer #1 = You can't go to the bathroom while its charging, because you need to stand there and watch it charging?

:eek:

How about a smoke detector reading the fan exhaust?

:devil:
 

Wrend

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You guys don't have chargers with stop and start buttons? :nana: Maybe just a power switch would work well enough.

Hey, there you go. Get one of those cheap 9V smoke detectors to hook up to it.

Nice charging box, by the way. :thumbsup:
 
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tandem

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Another issue I have with this box and any like it: you are venting any fumes to your indoor atmosphere. Aside from the fire risk of cells reaching thermal runaway, another major concern is the toxic fumes various lithium rechargeable cells give off when venting.

The fumes are toxic and corrosive and could theoretically make a real mess of any electronics / computers and such in the affected area. Venting the fumes to the outside would be prudent if you are that concerned.

Another issue the box doesn't address, and can't practically address, is the occasional episode of mostly bad cells to vent / rapidly disassemble / explode / etc after the charging process is complete - when the cells are used in a light. Unless you add some remote arms to the box so a test run can be done with the flashlight they are intended to, I don't see how a charge-only safety shield helps.

While I admire the intent and hard work that went into the box, I can't help but wonder if your actual vs perceived safety would be better served by buying only high quality cells from reliable sources. Furthermore, high capacity cell users are better served by chargers that don't take 11 hours to charge a pair of 18650 cells. That's simply too long to ask users to be vigilant over their charging station in my opinion.
 

tam17

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@Wrend:

Somehow I'm missing the point here: how the Stop/Start button could possibly alleviate the consequences of a faulty lithium-ion battery randomly venting with fire while still in charger (or a similar mishap)?
 

901-Memphis

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I put my pila in a crockpot when i charge sometimes.... How much did that sheet of lexan cost you?
 

Wrend

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@Wrend:

Somehow I'm missing the point here: how the Stop/Start button could possibly alleviate the consequences of a faulty lithium-ion battery randomly venting with fire while still in charger (or a similar mishap)?

Just joking around a little here, but that aside, it would give you time to use the restroom instead of watching your cells constantly. They're less likely to pop when they're not in use.
 
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