A123 batteries
 

Where can i find info about this batteries and where can i buy it??
And, is this a good alternative to li-po packs, performance, charge rate, weight, runtime, etc....

And wich charger can charge this type of cell?? I've a Duratrax ICE, can i charge it with this charger??

Need your comments please.

thank you

Here is the main site: http://www.a123systems.com/newsite/index.php#

Here is a site for just the R/C packs: http://www.a123racing.com/

For cheaper build-your-own options, consider picking up a Dewalt pack on eBay. You get 10 cells for usually around $100 give or take. You just have to disassemble and re-assemble in whatever formfactor and setup you want.

For the charger, you should get anything that either has a A123 profile, or an adjustable CC/CV threshold setting that goes down to 3.6v. The Astroflight 109 - A123 and the Xtrema charger are two that I know of that have that capability, but there may be others. I have the TME Xtrema and it works very well. You could also get the lipodaptor, which lets you use the NiMH charge setting on any NiMH charger and the adaptor will shut off when the pack voltage gets to 3.6v/cell. The only downside is that you won't get the CV stage of the charge, but these cells don't take much at that point anyway.

OK Brian, my ICE charger have a CC/CV charge profile, for li-po (3.7v/cell and li-ion 3.6v/cell).
So i consider that if i select the li-ion profile, i'll be able to charge the A123 pack???

My charger can only charge 4s li-po, so it will charge also only as li-ion, so if i buy a DeWalt pack on Ebay, the only thing i'll can do is to make a 4s arrengment, right?

But can i built a 4s2p? and please, tell me the difference between a 4s and a 4s2p configuration. Is on the 4s2p i'll have twice the runtime of a 4s configuration??

Last, could you tell me what's the capacity of the A123 DeWalt pack in mAh??

Thank you very much ;-)

Ho! forgot to ask, at wich amps can i charge this pack, should i charge it at 1C like li-po cell??

David

you can build 4s2p, or just 4s to save weight. i bought two 4s2p packs from a123, and bought two 3s1p (wired in parallel, so i can have 5s2p) from someone on ebay. building them seems easy, but i just didn't want to mess with it.

i had 2 Ice chargers as well, but it won't balance the a123's. so i sold one Ice (about to throw the other one on ebay) and bought a123's charger. it's a fast charger, plus it balances the cells.

Actually a123 cells require a 3.3v profile. Lipo is 3.7, LiIon is 3.6 and a123 is 3.3 just to confuse things.

That's the rated nominal voltage, don't forget.

Lithium Poymer (lipo)
- 4.2v/cell CV, and less than or equal to 1C charge rate (CC)

A123 chemistry (M1 cell)
- 3.6v/cell CV, 10 amps charging (4.3C) at this voltage
- Anything higher than 10 amps charge, 3.8v/cell should be used to get the rated mah into the cell.

-I don't know what the actual limit as far as charge rate IS, but I have seen these be charged at 10C (6 minutes), safely.

As for how to configure them (Dewalt 36v packs) for RC use, THIS should prove helpful. They have a rated capacity of 2300/2400mah per cell, depending on where you read about them.

I am at roughly 150 cycles on some of my cells, and they still give 2375mah, if you can trust the Eagletree data.

There is some interesting options for charging 3s packs of them. Perhaps you should consider a 6s setup.

Highflier