a123 6.6v questions

[jhautz]

Originally Posted by VintageMA

Just from my experience (which was very short lived for now) with the A123 cells, they don't hold their rated voltage under load. Granted I was using a 1P setup which didn't hold it's voltage as well as the 2P systems will, but check out the specs on a 2S2P pack here: http://www.a123racing.com/SpecSheets...te_14Aug06.pdf You will be getting about 6 volts on 2S2P @ 23Amps. @ 69Amps you are only talking 5 volts (2.5v per cell)

The packs are very heavy and very bulky. I went with the 2 of the 2S1p packs in hopes of using it in a CRT.5 project @ 13.2v. After running that and comparing it with my 3S 5000mAh Maxamps lipo packs I have to say that I am much happier with the lipo packs. The lipo pack is smaller in size than the 4S1P A123, holds more than 2X the charge and is lighter as well. The A123 cells do have a great punch, but due to the low storage capacity they seemed to dump pretty quickly.

I've never had a problem with lipo when using a decent brand (Maxamps, TP, Kokam/Orion, or TrakPower/FlightPower) so I think I will stick with them until the A123 technology matures over the next few years (which I am sure it will and am definitely looking forward to). IMO the power density (even when compared to NiMH) is too low making for a heavy pack and the cells are too cumbersome for easy placement.

I had similar results as you with did running my lightning staduim 10 on 4s1p a123. I actually found that running 3s2p gave me better acceleration and better top end witha little gearing adjustment. I'm carrying 2 extra cells around now, but they perform much better.

BTW someone mentioned a 1940/7 drawing to many amps for the a123 eariler, but I actuially think that it would be fine. I run a 1940/7 in my savage with 5s2p a123 and it rubns great. Because I didnt need a LVC with the a123 I was able to use an older style BK controller I had around. If you run a123 the 9920 and 12020 become very atractive options again.