Da Fuq needs super caps??? (anyone seen this??,.New lithium)

[Kyblack76]

[philrab]

I'm of two minds.

A. Yes, Lithium based batteries CAN cause some horrendous fires when they fail. Coming from the aviation community for years, I can tell you Boeing went thorugh all kinds of Hell getting the FAA to bless off their Lithium Ion battery in the 787 Dreamliners. Those battery systems have TONS of safeguards in and around them, cause if they go nucleur and take out the electrical system of that aircraft, it's going to make a very big hole wherever it lands. So, the concern for a protection circuit or other safeguard on these batteries is well warranted.

B. But, Lithium based batteries have been in common usage for over a decade, and failures in common devices aren't a regular thing. The primary failures seam to stem from abuse, or the battery being pushed beyond it's design limits. If they're are properly rated, maintained, and cared for (on top of properly designed) I imagine things will work their way out.

Personally, I won't be an early adopter, but I'm not banging on the company or Taylor. Gotta experiment and try new things or you never get anywhere.

I will say, to Taylor and anyone else, I really wouldn't recommend running these in your cabin unless it's in a sealed battery box vented to the outside of the vehicle, just for safety's sake. At least not until they've been out and around long enough we know they're safe to use otherwise. That's just a big CYA.

[Keith77]

You know how pissed I'd be if this thing killed me?

Lol

Burning the earth down.... please dont...

Well... apparently I already created a black hole at finals. Might as well cause a nuclear meltdown too.

Thats a lot of DB's

[P4killer_]

Lmao 1.1k db. There is no way thats right.

[ToNasty]

You know how pissed I'd be if this thing killed me?

Lol

Burning the earth down.... please dont...

Well... apparently I already created a black hole at finals. Might as well cause a nuclear meltdown too.

Thats a lot of DB's

hahahaha this made me spit water everywhere

[CortezDTV]

The lack of knowledge is amazing

The batteries can still be dangerous de gassing is going to kill you at a much higher rate than the explosion

The fumes when an extreme overcharge or over current are very toxic

But they are barely if any more dangerous explosion wise than an over charged compasitor like everyone here uses

You short a big lead acid equal to the compasity and discharge rate it will burn your whole car up too

Real problem lies with the fumes and then in the hard to put out fire

Lithium explosions or flames can happen underwater in space because they are a self sustained source

Lithium batteries are beast

My concern is when I someone actually wires up some cells live I've been considering

You won't be able to compete eveyone will just bitch that you cheating etc blah blah blah unfair advantage then it will create its own class or something

[SnowDrifter]

Let me just chime in and say that there are a slew of lithium battery chemistries right now. Some more picky than others. IMO the most forgiving are the LMO (Lithium Manganese Oxide) batteries. AKA IMR batteries for you vapers. Only time you really hear of those failing is when they are severely overloaded... Which brings me to my point

Lithium batteries have 4 main failure modes

Exceeding the load limit (thermal)

Overcharging

Over-discharging

Age

When li-ion batteries go thermal, they tend to "run away" pretty quickly as once you have enough energy added to the system to kick start a reaction in the battery, it's game over. Think of heat as a catalyst. The less heat the better, to a point anyway. Keep them cool and they'll last longer. Under hood isn't a good place for these.

Overcharging will severely reduce the lifespan of a cell. Too high and the anode plates itself and the cathode turns into an oxidizer. Essentially they go boom in a big ball of fire. In this way they are similar to caps - DO NOT OVER CHARGE. I'll say this again: DO NOT OVERCHARGE. Both caps and li-ion batteries will go poof.

Over-discharging is considered below 3.0v. Continuing to go below that will cause microscopic copper "hairs" to grow inside the battery. If those get long enough to cause a short, the battery is rendered unusable. As a matter of personal preference I wouldn't discharge below 3.6. There is very little capacity below that point and it only serves to put a great deal of stress on the battery.

Age is the ideal failure mode, the internal resistance will build to a point that the battery no longer performs as desired. This is a safe failure mode and requires replacement. There is no way of reviving li-ion batteries like there is with lead/acid or Ni-MH batteries. Note that storing or operating li-ion batteries in a partially discharged state is perfectly safe. These batteries aren't harmed by being partially charged.

Some notes regarding charging: They can't be charged below freezing. The anode in the battery plates itself causing internal damage. You'll see higher resistance and decreased battery capacity. Charge profiles are very similar to lead acid batteries, cc/cv. It's interesting to note that unlike traditional 12v batteries which might charge at 14.4v then drop to 12.8 when the charge is terminated, li-ion batteries are charged at 4.2v per cell and remain at 4.2v when the charge is terminated. I would rather they be a bit under charged to 4v or 4.1v than overcharged. Without using complicated charge circuitry, your options are limited at this point to 3 or 4 cells - corresponding to 12.3 and 16.4v charging at 4.1v per cell. You'd need to modify your alternator to be non-temperature-compensating. Need to have the same voltage hot and cold. Externally regulating them would be your best bet for this.

IMO, your "safe" li-ion battery pack would consist of several smaller individual modules of either 3 or 4 cells wired in series, fused individually, and including a balancing circuit. It would also have airflow for cooling and to allow a pressure release should a cell fail. It would also have flame retardant, non conductive, thermally insulating dividers between each of the smaller modules. Should a module or cell fail, the heat produced will not cause a failure in the rest of the pack. The fuses are so if a cell shorts out, there won't be an inrush of current from the other good cells causing a thermal overload. The fuses will also serve to prevent a current overload in an over-current scenario. You'll need to match the fuses to either the charge or discharge rating of the battery, whichever is less. Then you'd need to build enough of these modules to satisfy your current demand. Once you have that THEN you can assemble a battery pack. Bear in mind that you want the final pack in a location isolated from both heat and freezing and still allow airflow (this can be plumbed in with fans, doesn't need to be passive)

To recap: As long as you don't exceed the limits of the battery (thermal, voltages, current demands, temperature) they are really quite safe. Capacitors are too. Be familiar with them, build to the battery's needs and you shouldn't have an issue. By all means build it so it's safe even if there is one, but your failure chance should be pretty slim. Consider that li-ion batteries are in your phone, laptop, iPod, portable speaker, power tool, flash light... They're everywhere. Keep within their design range and failures are few and far between

[SnowDrifter]

Hah I like how "chiming in" turns into a page. Whoops

[dangaranga]

Hah I like how "chiming in" turns into a page. Whoops

No that was a great post.

I hate when people blindly discredit something or make generalizations without even a BASIC understanding, such as recognizing the different lithium chemistries.

and people need to be aware of the safe operating conditions and behaviors for these batteries (like with caps) and have measures in place to ensure safe operation

Edit: Here's some recent info and discussion posted by Kevin on Caco for those interested

http://www.caraudioclassifieds.org/forum/wiring-electrical-other-installation-equipment/176103-juicebox-battery-lithium-iron-phosphate-pre-ordering-pricing-configurations.html

[pioneerforlife]

Let me just say, for the price of one of these, you could get 3-4 banks of caps. that right there is more powerful than one of these batteries and much

safer. i have seen 3 banks shorted and ya it wasn't pretty but the car didn't burn down. all it did was spark a lot. caps discharge quickly anyways so even

if there was a dead short it wouldn't last very long.

As some of you know i am not very nice to my equipment at times lol. I ran 6k+ on a single bank of caps. ya, thats way to much. My voltage was terrible.

but as soon as i would let up on it they would charge back up. then i could go for another 20 seconds lol. you could not abuse one of these batts. my point is, there are a lot of people in the audio community that know what they are doing, and if you do, you won't do stupid shit like me and run your voltage stupid low lol. but there are even more people out there that have no idea what they are doing. those are the people who are goanna blow one of these up in their car.

with that being said, i wouldn't run one of these. ya i know what i am doing for the most part, but i still have a lot to learn. and i know i have been super careful when working on my car but despite that, i have shorted things out. it happens to everyone from time to time. you do that once with one of these and you may be outta luck.

i mean what happens if your alt dies on you outta nowhere. what if you drop a screw on the terminals. what if the cover slips off your fuse holder and the wire grounds out. you may think this will never happen, but i have seen or had all three of these happen before. it's not worth the risk. The one time something happes it will be the last.