Poor man's lithium

[RobertSmalls]

The 18650 is a little bigger than a AAA battery: 18mm diameter, 65mm length. So that's why it's only 1Ah. It might be fun to see how far you can go on a charge on one of those.

[roguethunder]

Originally Posted by RobertSmalls

The 18650 is a little bigger than a AAA battery: 18mm diameter, 65mm length. So that's why it's only 1Ah. It might be fun to see how far you can go on a charge on one of those.

Random interjection...
More half way between an AA(A really, but I doubt many folks here have seen a cylindrical A cell before) and C cell tho slightly longer than even the latter... Also from what I referenced normal Ah for such a cell is 2.2-2.8Ah, so that's actually pretty sad at 1Ah. Factory 25ths indeed XD

XD... Tho yeah. Nothings going far on that unless its a RC car... And not much of an RC car at that.

vpoppv, feel for ya... batteries just aint cheap. If they were electric cars wouldn't be having nearly so much trouble price-wise...

[Grimm]

I recently dismantled 70 some used lithium packs that were going to be thrown away and they were almost perfectly usable. The physical size is a 4/3 A. Digikey has plastic holders for them with terminals, I bought a dozen and I can look at the part number for you if you want. But if you just want a couple hundred cells to play around with they're sitting in a box in my house. I'd be perfectly willing to send them your way, just make me an offer. And I think they're all charged to boot.

For charging I use a Bantam BC8 with a harness I made myself. It charges and balances 8 cells at a time. Not ideal for you, but it does export the data to a computer so you can look at the charging curve.

[vpoppv]

Originally Posted by Grimm

I recently dismantled 70 some used lithium packs that were going to be thrown away and they were almost perfectly usable. The physical size is a 4/3 A. Digikey has plastic holders for them with terminals, I bought a dozen and I can look at the part number for you if you want. But if you just want a couple hundred cells to play around with they're sitting in a box in my house. I'd be perfectly willing to send them your way, just make me an offer. And I think they're all charged to boot.

For charging I use a Bantam BC8 with a harness I made myself. It charges and balances 8 cells at a time. Not ideal for you, but it does export the data to a computer so you can look at the charging curve.

I think this is exactly what I was looking for! My car is already red, so a big plasma fire will look super impressive under the hood I think.

[roguethunder]

Originally Posted by Grimm

I recently dismantled 70 some used lithium packs that were going to be thrown away and they were almost perfectly usable. The physical size is a 4/3 A. Digikey has plastic holders for them with terminals, I bought a dozen and I can look at the part number for you if you want. But if you just want a couple hundred cells to play around with they're sitting in a box in my house. I'd be perfectly willing to send them your way, just make me an offer. And I think they're all charged to boot.

For charging I use a Bantam BC8 with a harness I made myself. It charges and balances 8 cells at a time. Not ideal for you, but it does export the data to a computer so you can look at the charging curve.

Sounds about par for the course.
Laptop batteries are commonly in excessively stupid battery layouts.
Things like 2 2 2 1 (7 cell) 2 2 2 1 1 (8 cell) 2 2 2 2 1 (9 cell).
One can easily guess that the 1's in serial fail LONG before the parallel pairs. And even when they're not and its 2 2 2 2 (proper 8 cell) a random worse battery can often pull a pair weak, and then the other one in the pair fails due to the stress. Although this happens a fair bit less often and usually takes many more cycles unless the initially failed cell was outright defective.
At-least that's what I could figure from the dozen or so I took apart out of curiosity and a little research. Computer hardware is one of my... interests.

Should be interesting to see what kind of C you can pull off these cells without them going up in flame or dieing in very few cycles. Though another problem that may arise is sometimes even same-cell count packs for the same exact model laptop, come in different amp hour ratings, and balancing all the different cells could be... Interesting.

Other note, even if they were charged. Lithies, particularly the ones used in laptops? Bleed rather badly.

Good luck tho be careful. Particularly with any sony cells. They're prone to occational internal contaminants that well, causes them to be extra volatile.

[vpoppv]

I've collected some laptop batteries. I got a charger. Watch out Tesla.....

http://www.youtube.com/watch?v=ICzo_WU518Q

[vpoppv]

Here's an article with Toyota and Tesla:

Toyota already building EV prototype with Tesla battery pack? — Autoblog

There was a mention of a link between Panasonic and Toyota. As a side note, in my destroying of bad laptop batteries, so far I have found that the batteries labeled "Panasonic" tend to have a voltage (in the 4+ volt range) straight out of the bad battery pack, and only ONE of the batteries in "Panasonic" packs tends to be bad, whereas in packs without a manufacturing tag tend to die in pairs, and even good batteries tend to hover in the 2v range....

[Nevyn]

If you're willing to cover shipping, I'll send you a WHOLE bunch more....

[MPaulHolmes]

Panasonic makes very good quality stuff. I think the tricky part is getting all the batteries connected in series and parallel with those nickel tabs. Usually, people use a big machine that uses 2 pulses. The first pulse vaporises the impurities on the 2 surfaces, and the next pulse of about 3000 amps welds them together. I bet there's a way to do that that's similar to a motor controller. PWM can do anything. The pulse is for only needed for a couple millisec I think.

[vpoppv]

I keep reading and re-reading about the Tesla pack on their website. This time, I caught a little error! Here's a quote from:

Battery | www.teslamotors.com

"Sixty-nine cells are wired in parallel to create bricks. Ninety-nine bricks are connected in series to create sheets, and 11 sheets are inserted into the pack casing. In total, this creates a pack made up of 6,831 cells."

Now: 69 (cells) times 99 (bricks) equals 6,831

But, if there are 11 sheets, that's 6,831 times 11 equals 75,141!!! At about 39 grams each, that's almost 3000 Kg. Since the pack weighs about 900lbs, maybe they just don't use the 11 "sheets" they talk about?

Here's what one cell can do:

http://www.youtube.com/watch?v=TtVXQEe8h8k

Edit: That cell is uncharged, straight out of a "dead" laptop battery pack!