Just vented my first 2 batteries

[Spencer87]

I am Nearly 100% sure that the batteries were inserted correctly.
Like 99.9 percent sure... I remember because I have stickers on the positive ends of the battery and I remember seeing them lined up... and I took them out of the charger and put them in right away, so there was no was i could have flipped them... and they started smoking both from the same side... So unless one vented out the bottom. Plus I doubt that would be an issue without an Atty and no fire... its just a plastic sled with no power to course through it.

As much as I dont like to admit it... I think I need to go with @DaveP
I remember putting the bottom in and then using my palm to pop both batteries in, and I pushed them in at the same time this time, instead of one at a time. I suppose on of the batteries tore, maybe ebven just very small and shorted one of the batteries that shorted the other..... or something like that... more likely than inserting one backwards.

 

[ENAUD]

Have you tested the mod, switch, and terminals with a multi meter to try to find a short after the event?

 

[Spencer87]

Have you tested the mod, switch, and terminals with a multi meter to try to find a short after the event?

Nah I do not know how to do any of that kinda stuff , even though I have a multimeter, Unsure of how to testthe mod

 

[BoogaWu]

Now that's its burned up, I kinda doubt tests would be accurate to the time of incidence anyway. I think you had a wrap crack personally, but it's as important that people act quick and toss that mod like a hand grenade, imho, then why. And hopefully when peeps read this, that is what they do.

 

[VHRB2014]

Personally, I would never buy a mod that has those bent metal contacts both top and bottom like that. On just the negative, they are OK as the battery can be slid into position without worry. But on the top, there is a real high chance it will rip the wrapper on the top and then make contact with the negative casing and the positive terminal all at once, and then you have no warning, it just starts sizzling and a smoking. You need to remember that without the plastic sleeve, the negative and the positive are only separated by about 2-3mm of space in-between them at the top of the battery, the negative is the whole battery tube right up to folded over nub at the top.

 

[crxess]

At minimum, one had to stay shorted at the top to Ground the Positive rail and short the second battery in a Parallel setup. That or the upper + rail got grounded by a lose contact to the chassis.
What gets me is all the Damage is at the Negative end of the mod and the positive of the Batteries.

 

[beckdg]

Glad you are ok! I have read so many times that most vents happen right off the charger and batts should rest off the charger for an hr before use. I wonder if it would have made any difference?

No

It wouldn't

Focus on such is inflated tremendously for the purpose of promoting safer practices despite efficacy and usefulness of each practice. Rather promote the whole practice than reflect on the usefulness of each individual practice.

Tapatyped

 

[beckdg]

Am I seeing things, or do I see some tears in the insulator wrap of the bottom battery? Looks like bare metal front and center. If so, this could cause a battery hard short when the bare cell body came into contact with the mod body. That plastic shrink wrap is there for a very good reason.

I don't think its a coincidence that a lot of the battery venting/explosions involve purple Efest batteries. It's now well known that Efest re-wraps reject cells from the major battery manufacturers, yet for some reason people still use them.

Purple Efest Batteries Not As Advertised




Rest batteries after charging
One commonly-reported factor in almost all the incidents we hear of where batteries failed violently while in use is that they were taken directly off the charger and then used immediately, at which point they failed.

Because of this, we think it may be a good idea to rest batteries after charging them. This advice will not be found in the usual 'reference bibles' on batteries, but we see more and different reports than others. Therefore we now advise:

Do not use batteries directly after charging them. Use a battery or batteries you previously charged, and that have rested for several hours. This is especially important if using a stacked pair for higher voltage, as statistically the risk is far higher. --- rolygate

The benefit to resting is increased battery lifespan & minimize chance of venting.

Tear in side of battery wrap would not cause this.

Negative terminals look as if they might actually contact the mod body.

Regardless, pos terminals are wired in.

There would have to be contact of the positive terminal wiring to the mod body for that short to happen.

In other words, faulty or failed wiring.

Tapatyped

 

[VNeil]

Regardless of the real reason for this it should be obvious that dual parallel mech mods are a Very Bad Idea...

 

[beckdg]

I agree that it was probably a reversed battery that caused it.

Then you are incorrect.

Reversing the battery (ies) will not close the circuit and cannot cause a short or any issue that could cause thermal runaway.

DISREGARD

Tapatyped

 

[beckdg]

EFest batteries are pipe bombs, this malicious company takes reject batteries and rewraps them with grossly exaggerated ratings. This is well known and documented.

So yes the batteries are rightly suspect.

Sent from my Nexus 6 using Tapatalk

Wrong

Dead wrong

Without a current path, there's no possibility for a short

Nothing to blow even the worst batteries

The mod is the problem

Period

Tapatyped

 

[beckdg]

Heat Discoloration from the Rapid discharge & contact reaction between dissimilar Metals.
Think of Bluing a Mod for custom color.
As a Parallel mod, I hate to say, but it really sounds like you mistakenly dropped one battery in backward. I've done it several times.........fortunately in a protected single battery mod.

Mike, Mike, Mike

Buddy

You know better

What closed the circuit?

NVM... MORNING STOOPIDS

Tapatyped

 

[beckdg]

Nah I do not know how to do any of that kinda stuff , even though I have a multimeter, Unsure of how to testthe mod

PM me

I'll send you my mailing address

Send it ATTN PLEASE METER and I will photo the fault and forward the photo.

Tapatyped

 

[beckdg]

Regardless of the real reason for this it should be obvious that dual parallel mech mods are a Very Bad Idea...

Okay...

Make your case.

One without massive holes.

Tapatyped

 

[VNeil]

Okay...

Make your case.

One without massive holes.

Tapatyped

If you reverse one battery you get two batteries in series, with a dead short between the outer positive and negative terminal. What is so complicated about that case?

 

[DaveP]

Then you are incorrect.

Reversing the battery (ies) will not close the circuit and cannot cause a short or any issue that could cause thermal runaway.

Tapatyped

I may have missed it, but I didn't see anyone specify what mod brand and model was involved.

It depends on whether there's diode protection in the circuitry and whether the mod is wired in series or parallel. Thermal runaway CAN be caused by a tear in the battery sleeve. All it takes is case contact with the mod's terminal and you have a dead short across positive and negative. What's funny is that both batteries apparently went in meltdown. He reported two pops.

What happens if you reverse a battery in this mech mod?

 

[beckdg]

If you reverse one battery you get two batteries in series, with a dead short between the outer positive and negative terminal. What is so complicated about that case?

LOL

DOH!

I should probably refrain from posting before I'm awake.

I didn't think about the sled connecting the pos to pos AND negative to negative to close the circuit.

I'd still rather have the option.

AND a 2 battery mod can be designed so that 1 side of a terminal is an open circuit preventing such issues.

Tapatyped

 

[VNeil]

a 2 battery mod can be designed so that 1 side of a terminal is an open circuit preventing such issues.

Tapatyped

But they aren't designed that way. They are in fact designed to guarantee a vent as a penalty for reversing a battery. That is one reason you never see certified or approved consumer devices that use parallel battery connections.

 

[VNeil]

But they aren't designed that way. They are in fact designed to guarantee a vent as a penalty for reversing a battery. That is one reason you never see certified or approved consumer devices that use parallel battery connections.

And if they were it would just delay the venting until the mod is next to the user's face. Not a good solution...

 

[VNeil]

I may have missed it, but I didn't see anyone specify what mod brand and model was involved.

It depends on whether there's diode protection in the circuitry and whether the mod is wired in series or parallel. Thermal runaway CAN be caused by a tear in the battery sleeve. All it takes is case contact with the mod's terminal and you have a dead short across positive and negative. What's funny is that both batteries apparently went in meltdown. He reported two pops.

What happens if you reverse a battery in this mech mod?

And similarly a single short due to a torn wrap would short both batteries, assuming the positive and negative terminals are hard wired together via the battery sled