True, shorts do happen. With a protected battery, like an AW 3400mAh, short-circuit protection is there, along with over-discharge protection. So if a short happens, the protection circuit kicks in and you are safe. With a battery that has no short protection, it releases a HUGE amount of energy.
However a protected battery with a faulty protection circuit that doesn't protect against shorts or over-discharging, may be a big problem. Which is why purchasing decent protected batteries is pretty important. But either way, I would rather have a protected battery that can stop shorts or over-discharging rather than a non-protected battery which if exposed to a short, will 100% short out and release an insane amount of energy.
Basically:
- Non-protected batteries will short out 100% of the time if they are exposed to a short.
- Protected batteries will only short out of protection circuit is faulty or doesn't have short-circuit protection.
Ryedan said:
It is generally accepted when looking at the whole picture that unprotected safer chemistry batteries are safer than protected ICRs. In addition to what you've listed above,
there are two more differences between them. The safer chemistry battery will not vent with flame like ICRs do. I know IMRs behave this way but I'm not sure about the other safer chemistries.
The second is that safer chemistry batteries need to get significantly hotter before they start venting compared to ICRs.
For mechanical mods I use IMR only.
I would much rather have a IMR vent in my K100 than have a ICR vent with more energy with increased likelihood of turning my mod into a pipe bomb. Just my
Ryedan just made the point that I was going to make. Safe chemistry batteries are inherently "safer" (admittedly a relative term when speaking about batteries) than any ICR chemistry battery, protected or not. The only reason that ICR batteries can be used for our application in the first place is because of the protected circuit in the protected batteries. This is because, without the protected circuit, they are considered to have a
volatile (as in "flames) chemistry which means
when they go into thermal runaway, it is often with flames or explosion.
Case in point, my first mod was a mechanical mod. It had a collapsable hot spring, no vent holes but the fire button was designed to vent gas. I was using a protected ICR battery. Pretty safe, right?
The mod was kept in a pants pocket in my locker at work. The fire button became compressed in the pants pocket and allowed the battery to fire continuously. The battery over-discharged and went into thermal runaway. Luckily I found the mod and the battery going into meltdown mode before a fire started. When I found it, the mod was too hot to touch, was releasing hot gas from the fire button and melting the paint on the mod, the below battery had melted the shrink wrap, ruined the fire switch and the hot spring, and ruined a perfectly fine pair of pants.
The fire switch did as it was designed to do by venting gas, however the protected circuit in the ICR battery and the hot spring had failed to prevent a potential catastrophy. Had I not found the situation when I did, it could have been much worse and caused a fire.
If this had been a regulated mod I would not have had this story to tell. The better protective circuitry in a regulated mod would have more layers of protection: over-discharge protection, auto cutoff of the battery after so many seconds, hot spring protection, and the recommended safe chemistry IMR battery.
Too many novices and even long term e-cig users do not have the education or knowledge of li-ion battery chemistry or use safe battery practices. Most believe the higher the mAh rating, the better the battery is. They are often buying the cheapest batteries that they can find. Even many of the e-cig salesmen in vape shops apparently don't know what's safe.
Just this weekend a novice vapor purchased a
mechanical mod that uses an
18350 battery. The sales person sold him an RBA with a coil he set up with a
0.4 ohm coil. No 18350 battery has the amp rating to safely use a 0.4 ohm coil.
That's a 10.5 amp draw;
the continuous discharge rate of an 18350 battery is only 6 amps. If a protected ICR had been used, it would have been an even more critical disparity.
http://www.e-cigarette-forum.com/forum/general-e-smoking-discussion/487382-help-me-my-battery-yo.html
This was not an isolated incident. This has become a trend. I can recount several such incidents on this forum in the last few months.
Yes, a safe chemistry battery can vent in thermal runaway as an ICR battery will, but it will do so by simply releasing gas but without flames and explosive force like an ICR battery will. This is why protected batteries are no longer recommended for mods, but safe chemistry batteries are. This is why some battery vendors like Orbtronic have the disclaimer, ""Protected Li-ion 18650 batteries are made for high performance flashlights, not for e-cig mods."
They show a Li-ion battery going into the case on the site. No additional insulation is needed with this device.
