Lithium cell tests

[flippt]

Lithium cell tests

Enought with the spamming, alright!?

[swanaldo]

Lithium cell tests

Chill Joacim just a bit of fun you see. the forum is pretty boring at the mo and just trying to spice things up a bit. its not spamming

[babeth]

Lithium cell tests

No, its Swanning, and just as annoying.

[craig_colliass]

Lithium cell tests

Shane this is the Geek thread you must €œknow your onions€ before you say anything here, or they shoot you down in flames.
That€™s why you never catch me putting any comments here, I run cheap SLA batteries and I always loose.

[leorcc]

Lithium cell tests

That is not true Craig, if you dont know your onions this is the perfect place to ask about them.

This topic doesnt need livening, there are separate threads and topics on this forum specifically for that.

[craig_anto]

Lithium cell tests

just a quicky, can the a123 cells be charged in paralel?
for example, 3 cells in paralel wired in series with another load of paraleled 3 cells?

[nick]

Lithium cell tests

Yes. Though the connections between the cells need to be substantial.
http://www.killacycle.com/photos/battery-assembly-110s-x-9p/http://www.killacycle.com/photos/bat...bly-110s-x-9p/

[terrorhurtz]

Lithium cell tests

Yup, you can do it with lithium cells, but not with NiCads, because the voltage drops when NiCads are over-charged.

This is one of the packs for beta (6S4P):
http://www.b-e-t-a.com/24cells.pnghttp://www.b-e-t-a.com/24cells.png
cells joined by 0.5mm copper sheet.

Makes it much easier to balance the cells (and only six balance wires to build into the pack) - you balance it as one pack, as opposed to four separate packs.

(Message edited by terrorhurtz on September 12, 200

[terrorhurtz]

Lithium cell tests

Hyperion also do some battery bars specifically for A123 cells:
http://aircraft-world.com/shopexd.asp?id=5085http://aircraft-world.com/shopexd.asp?id=5085

Not that theyd be suitable for a parallel pack.

[terrorhurtz]

Lithium cell tests

Laptop battery packs are also built with the cells in parallel:
http://www.b-e-t-a.com/LaptopCells.jpghttp://www.b-e-t-a.com/LaptopCells.jpg - 3S2P

(Message edited by terrorhurtz on September 12, 200

[woody]

Lithium cell tests

Probably rubbish ...but worth a punt?

Should be good enough for a Feather.

http://www.dealextreme.com/details.dx/sku.5105http://www.dealextreme.com/details.dx/sku.5105

A quick Google around gives a probable continious discharge rate of 15C.

BUY 10 or more ...go to checkout click BULKRATE and the price drops to $34.69 including shipping!

[tough_as_nails]

Lithium cell tests

I think i will need to get my money back from robotmarketplace. My A123-cell packs arrived and after removing the shrinkfoil, it seems they solered all the vent holes from the cells. Tomorrow i will put a picture online. :sad:

They dont supply what they promise on there website:

These packs are constructed with highest-quality triple-welded tabs, wiring strain-releif, and 3M Polyolefin Mil-Spec rubberized finish.

There are no triple- welded tabs used and only wiring strain relieve for 1 cable. I would advice not to buy it.



(Message edited by tough_as_nails on September 15, 200

[terrorhurtz]

Lithium cell tests

Note that the blue dot on the button (negative) end of the cell is not actually a vent - apparently it is where they are filled. And there is no vent on the flat (positive) end either. So shouldnt be a problem where they are soldered.

If you can have a look at the individual cell voltages when discharging and check that they are all similar capacity and that you can get at leat 2 Ah out of them, then I would suggest they are OK.

Would be good to see a pic.

[grant_ploughbot]

Lithium cell tests

Just out of interest, could you post a picture of the cells please?
Looking at their site, im not too sure they are actually A123 cells. Which ones did you get? the spec on their site says the higher capacity cells are only 20A discharge, 30A max. And they state the 1100mA cells as being A123s, but im pretty sure they only make 1 size.

[woody]

Lithium cell tests

Nope 3 are listed.

http://www.a123systems.com/#/products/http://www.a123systems.com/#/products/