Quote:
Originally Posted by ClodMaxx
well i called a123 to see if i could change my order (didn't have confirmation that it had shipped yet) to take one of the 2s2p packs out and replace it with 2 of the 3s1p packs, but alas - they were too quick. it was shipped already. so for the time being, i'll be running 4s instead of 5s.
so, i do plan to go up to 5s2p with the a123 cells...which is still only 16.5v. it's going to be on the heavy side...10 cells total, but i'm fine with that.
my question is this: can anyone see a downside to building a deans parallel connector to connect 2 packs that are 3s1p on one side? i would think it would be fine, just wanted to make sure. i could also tear a dewalt pack apart and build a 3s2p single pack, but i hate soldering. i'm ok at it, but i hate it.  |
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.