Li-Ion source

[koala]

OMG someone tell me this is true, alot of cpf members manage to use it

Pila 150A 50x19mm 1200mAh $27
Pila 168A 68x19mm 1800mAh $36
Pila 150S 50x17mm 1000mAh $23
Pila 168S 68x17mm 1400mAh $31

They are just cells aren't they? Why are they so overpriced?

Vince.

 

[LitFuse]

They have a protection circuit built into the cell.


Peter

 

[koala]

So that's what makes the cells safe and high price?

Vince.

 

[LitFuse]

Yup.

 

[koala]

How about this one

2x cells in a Battery 7.2volts 1200mAh for $6.50 each.

http://www.allelectronics.com/cgi-bin/category.cgi?category=search&item=LBAT-35&type=store

and this one for a groupbuy of 54(2x cells) $3 each.

http://www.ebtrades.com/pages/singleproductdesc.asp?ProdID=382

I ordered them, they should be here soon. Until I rip them apart and measure the sizes. We shall get some good supply of affordable Li-Ion cells.

Downside? These cells doesn't have protection circuit if they are taken apart but using them is not rocket science.

Vince.

 

[Deleted member 684]

At 1200mah, I wonder what kind of current can we draw from the battery? Still, 7.2 volts at sizes like that, it's a good source of power.

 

[James S]

They do have a circuit in them which does add to both the materials and manufacturing cost, but not anywhere near enough to warrant that kind of cost. They are expensive becuase LiIon cells are the latest high tech battery available and are "hot stuff" They are universally overpriced in every market that uses them from camera batteries to computer battery packs.

In time they will come down, but for now your only real choice is who is going to gouge you. ;P

 

[highlandsun]

Hm, sounds promising. The pack dimensions are about 70mm long, 19mm wide. Could be a pair of 17670s inside, but 1200mAh is a bit low capacity for such a cell. They may also be an old cell design. Interested to hear how it goes.

 

[koala]

I will report as soon as I get to rip them apart /ubbthreads/images/graemlins/grin.gif.

Vince.

 

[Ben H]

I'm gonna quess that they are 18650 cells. I ordered some JVC li-ion 1200mAh packs and they were Panasonic 18650 cells. I think that's why these packs are so cheap.....they are old surplus packs. Current 18650 cells are up to 2000+mAh. You should be able to pull 2C amps from these cells so that's 2400mA's. The tricky part is making sure you don't burn your hose down when you charge li-ion cells. I'm using some of these cells in R/C airplanes and they work great. I'm using a Lenmar MSC1L charger. The charger doesn't rely on the protection circuit in the pack to terminate charging. I use the charger to charge my Li-ion R/C packs and my 17670 li-ion cells that I use in my L4.

 

[CM]

More sources for bare cells:

www.slavin4u.com

www.sabahoceanic.com

Understand these DO NOT have protection circuit built in.

 

[koala]

Ben H is right about the Qualcomm battery pack...

The qualcomm cells reach me today and they were in fact 18650 cells.

To me, they are pretty good quality 1200mAh Sony cells, made in Japan.

And here's the protection circuit with a 4Amps fuse discharge cut off.

I am totally disappointed, I was hoping for 17650s. Due to larger diameter the Sony 18650 cells does not fit my Surefire E2e unless I bore it. So they go into my laptop replacement battery pack. If I can get to build a tube that can host this babies.

Vince.

 

[Doug S]

If these are really 1200mAHr cells, they are likely fairly old. I think that it has been awhile since Sony has made 18650 size cells with capacity of only 1200. There is a possibility that Qualcomm is still labeling the packs as 1200 but Sony is actually supplying higher capacity cells if these packs were built in the last few years.