New Lithium Ion Batteries from A123 Racing
 

Saw this posted up on another forum, so I figuered Id shoot the news over this direction. Looks cool, and from what these guys are saying these Li-Ions will NOT explode or catch fire. Web site is not finalized but the pitch is definatly eye catching. http://www.a123racing.com/

They call thier battery tech, "Hypersonic". Heres the pitch.

"Hypersonic™ the ultimate in lithium ion performance

Safe, durable, high power batteries for R/C vehicles. Hypersonic™ is the highest power density battery pack available on the market, safely providing up to 30C continuous output and 60C burst rates. Unlike traditional lithium-ion, Hypersonic™ packs have exceptional safety characteristics with no danger of fire or explosion. All component cells are UL-1642 compliant. Deans Ultra connectors are standard."

Try this link lol.. http://www.a123racing.com/html/hypersonicturbo.html#

I've been testing these cells for a month now.

They are great cells, but their current cell size is not applicable for 1/10 scale applications.

The good:

Supposedly, they have extremely safe chemistry with no thermal runaway, no possibility of explosion.

Their data shows amazing cycle life.

The bad:

The work best with a custom charger. The CC/CV at 4.2 V/cell that all Lipo chargers are programmed to, are not ideal for the A123 cell. They work best with a lower CV voltage.

They are HUGE. 26mm in diameter and 65 mm long.

Voltage of a Kokam LiPo is vastly superior. The 2.4Ah cells used in the Orion/Kokam lipo was averaging 3.14V/cell at 30 amps (that's per cell, the Kokam Lipo uses 4 cells. As a pack, it's averaging 6.24V at a 60 amp discharge!!). The A123 battery tested at 2.7V average at 30 amps.

Their capacity is low at only 2.3Ah.

A 2-series A123 battery pack would be roughly the same length of a 6cell nimh, but a lot taller and narrower, with less capacity and less voltage.

A 2series/2 parallel A123 pack would have equilvant capacity to Nimh, but it will be too wide (52mm vs 46mm) and too tall (26 mm vs 23 mm). It won't fit anything.

Bottom line, LiPo still offers better power and energy density, and the Kokam cells specifically, claim to be just as safe at the A123 cells.

Safety seems to be one of the only cards left in the diehard Nimh proponent's hand, in reference to thier case agaisnt Lipos. So for that alone I think these cells are note worthy.

I did notice that they are rated at 7.2V. Unlike 7.4V with the orion. So the voltage data you supplied really does not matter if one is looking for a 7.2v pack.