Li-Ion/Polymer 3.6v batteries... your experiences?

[Novastar]

I haven't seen much discussion regarding these, and as some of you already know--I'm a big fan of them.

I would love to see others experiences with them, thoughts regarding the technology--and where it might be going and so forth.

Here is what I've found so far. I will use a 3.6/3.7v Li-Ion 2400Mah 18650 cell as the sort of "basis" (so no one is confused as to what batteries I'm talking about):

POSITIVE EXPERIENCES:
* Effective 4.2v "starting" voltage
* Lightest in weight (it's lithium!)
* Safe for environment (Alkaline is awful for it)
* No memory effect (unlike Ni-Cad / Ni-Mh)
* Low discharge when unused
* Li-Ion tends to maintain its voltage over a discharge cycle
* Lasts just as long (or longer!) as any other cell for its size AND voltage (good or better energy density)
* 3.6v per cell is far better than even a smaller 1.5v cell in my opinion--especially for LEDs
* One cell can light up nearly any Luxeon LED... or most any other LED for that matter (despite it not necessarily being at the "maximum" brightness, depending on the LED type, color, etc.)
* Better variance in battery setups--less cells can achieve more power with less space used
* PCB protects for: over-drain, over-charge, over-discharge, short circuits, over-current draw, etc. -- it protects your cells AND your driver! In other words--if you make a wrong move... the PCB will generally save you.

QUASI-"NEGATIVE" EXPERIENCES:

* They are fairly expensive, even for one cell. Then again, I can't IMAGINE how many 1.5v alkalines you'd have to buy in order to equate the TOTAL lifespan of a 3.6v Li-Ion cell. No clue.
* The small PCB that must be on the battery to control/regulate the cells will drain a tiny bit of current (something like 1mA or negligible amount)
* When the PCB is tripped (for whatever reason), the voltage will read 0v, and the battery must be plugged into a charger to "reset" the circuit.
* Long charging times--well.. maybe not, but I suppose 4 hours to charge the battery is more of a "neutral" experience?
* Voltage increments are (obviously) very large... you can't exactly get "5v" without a regulator. You have 3.6, 7.2, 10.8, 14.4, etc. Then again, the voltage is not always the most important thing for LEDs... it is the amperage/current that is key.

Ok... that's it for now. Anyone else who has Li-Ion experience (and no I don't mean Lithium 3v primary cells)... chime in!

The last thing I can say is... these will come into play BIG TIME for anyone wanting a Tri-Lux kind of setup. 3.6v x 3... or 3.6v x 4. Trying to do that with 1.2v rechargeables or even 1.5... would be a nightmare in my opinion.

[987654321a]

li-poly, no way in hell will i buy that. watch this video why.

http://www.youtube.com/watch?v=SQ0SNESIkWk


ni-mh, is the best you dont have to discharge when you want to recharge it ni-cd leaves a memory

[Novastar]

Ridiculous argument.

Overcharging almost any battery will result in a catastrophic fire or explosion. If you're saying Ni-Mh or whatever other battery... can't achieve that kind of explosion with INTENDED ABUSE... you're in for a big surprise.

[987654321a]

oh i know alot about rechargable batteries i use them in my airsoft guns. yes of course every battery is going to turn into a fire ball when overcharged, but i would go with ni-mh or ni-cd, because they dont turn into a fire ball when they are gently tapped. i had a bad experience with a li- poly in my airsoft gun. i was playing at a canyon and idk how but my gun slipped outa my hands and hit the stock, that instant i stepped away knowing that the li-poly in there is going to explode. ended up going home with a $300 gun with a giant hole it in. li-polys are amazing but even when hit with a stick lightly, or bent or mishaped somehow they will explode and you wont like it. all the money you had spent on that nice saber would go in the trash. i mean think of it when dueling with that li-poly powered saber you have to be gentle with it and be careful not to hit the other saber too hard or your li-poly will explode. so it would suck for you alot. ni-mh, or ni-cd. all the way bro.

[Novastar]

Sorry to hear about your experience with the Li-Poly pack. My guess would be that + must have crossed to - when you dropped your gun. I wasn't there, so I don't know... but THAT would cause the pack to blow--as you probably well know.

However, I've now dueled with or "put into action" Li-Ion-powered sabers extensively (as in they are used and recharged several times a week), and not a single one has exploded. Not even after needing re-wiring, repair, etc.

I don't have any experience with Li-Poly, but my guess is you had some inferior packs, the PCB failed, or they just became too hot.

That being said--batteries should be housed in something stable that doesn't allow them to come into contact with objects, and also to protect them from overheating. No battery of mine in any saber (alkaline or otherwise) is able to be "hit" directly. Same to be said about allowing heat to get to them--they are heavily protected.

It would be silly to think slamming tiny cell batteries on a rock or (let's say) using a hammer against them would yield anything but dire consequences.

The battery cell type will not matter when and if the batteries are abused.

[neophyl]

Did the lithium in your airsoft gun have the protection circuitry ?

[987654321a]

yep. many airsofters i know have bought brand new li-polys from different hobby stores and got a stick and tapped them, and they still blew up, li-ion doesnt blow up but when overheated can cause a fire

[Novastar]

987... different packs allow for a certain "draw"... although I don't think that's your problem--I'm sure the batteries are not being "treated" properly by the airsoft guns.

Again, to confirm--EVERY single Li-Ion pack I have ever bought (and I use them alot--bought at least 20 packs)... have never once caused any problems.

Just recently, I short-circuited a pack by a stupid mistake... thought I killed the pack... the PCB tripped, and 24 hours later--they were fine.

[987654321a]

well im saying like faulty li-ion batteries but the ones your getting work fine, li-poly has alot of juice and it can power something for a long time and with more power.

[Novastar]

Right, the Li-Polymer tends to have about 10 to 15% more energy density ("punch").

I'm still unsure as to why your packs are blowing up.

At the risk of discrediting some site--where do you get them from?