A123 Safe Li-Ion cell in 18650 size

[SilverFox]

I just ran across this article.

The capacity is a little low, but no one has been able to blow up any of these cells. This is the same chemistry that is used in the DeWalt 36 volt tool battery packs. Those cells are larger, but we were hoping that they would offer them in the 18650 size.

I am not sure when these will be available, but I am keeping an eye out for them.

Tom

 

[Lurveleven]

Nice find! Same capacity as Saphion cells, but worse voltage under load than Saphion. Their 26650 cells has very good cold performance, much better than Saphion, so lets hope their 18650 cells have the same good cold performance.
Saphion cells appear to be hard to get at the moment, so these will be a very welcome addition, but the 26650 cells will be a much better choice for those that have space to use them.

Sigbjoern

 

[europium]

Not all that much capacity (at approximately 3.63Wh), but, HEY, look at the charge times:

Recommended standard charge method 1.5A to 3.6V CCCV, 45 min

&

Recommended fast charge current 5A to 3.6V CCCV, 15 min

:thumbsup:

 

[DM51]

Maximum continuous discharge 30A!

 

[Tronic]

Hi Tom

Sorry for hijacking your thread but....

Did you know that there already exist (and is available for sale) a safe 186560 size cell?
Say welcome to the Liion manganese cell!

I use 2 of this cells in my 2x18650 Wolfeyes setup for about 4 month now and they perform pretty well.

A few specs:
- 3.7V nominal (4.2V - 2.5V)
- 1.6Ah
- max discharge 10C cont. (16A) / 30C pulse (48A)
- low internal resistance (15 mOhm @ 3,6 V)
- you can use your existing liion charger
- no need for protection PCB (you only need a low voltage cutoff. No danger if overdischarged but you loose capacity. See Specs in link below.)

Here is a post from the manufacturer in a German RC Forum. (see post #22)

Here is a link to a old post from me with datasheet from the cell.

PS: Please let me know if you find that this is not the right place for this and I will move it.

 

[SilverFox]

Hello Tronic,

I am aware of the Sony cells, but for some reason, they never seemed to have caught on. The 26650 A123 cells have been very strong performers and a lot of the RC people have changed from Li-Po to the A123 cells.

This cell is the baby brother to the 26650, but is charged to a different maximum voltage. The Sony cells would be compatible with our existing chargers, and it seems they have a little more capacity. Perhaps we should find some and check them out.

Tom

 

[Tronic]

Tom,

I have the 14500V1 700mAh and 18650V1 1600mAh.
I can send you a few cells if you want to check them out.
Let me know...

 

[SilverFox]

Hello Tronic,

I would love to check them out, but shipping back and forth may be costly. Are they available over here?

Tom

 

[Tronic]

PM sent...

EDIT: Li-Ion manganese cells shipped to SilverFox for testing.

 

[FlashKat]

Are you guys talking about these batteries? I am curious about them.

http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=3071
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=3294

 

[VidPro]

here is a little brain fry info on the lithium iron phosphate cells. (not magnesium)
http://www.powerstream.com/LLLF-24v.htm

seems to me, they are lower capacity, still lightweight, lower voltage, and lower LIFE?
that one place puts them at 1 year for storage?

""overcharge tolerance of about 0.7V"" , woopie, because they still cant be balanced without balancing taps.

""Unlike the lead-acid battery, a number of LiFePO4 cells in a battery pack in series connection cannot balance each other during charging process. This is because the charge current stops flowing when the cell is full. This means that the LiFEPO4 packs need management boards.""

if they put great "management boards" on li-ion packs they would work lots better too. an example of the control method not the chemisty being what improves the use of the item.

looks like the application is more to replace heavy lead acid stuff, that has no "management" weighs to much, and doesnt like deep discharges

although the lesser voltage would closer match white led voltages.

 

[SilverFox]

Hello FlasKat,

Those cells are different from the A123 cells.

There seems to be a wide variety of "Li-Ion" cells coming to market. By changing the Anode material and/or the electrolyte mix, you can make these cells more resistant to overcharge problems. Keep in mind that different materials mean different voltages and capacities.

Tom

 

[65535]

A123 cells use a different cathode material that does not produce O2 so it will not self ignite.