'5s2p' A123 or '6s2p' A123 pack running 7XL motor  
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All Forums >> Radios, Batteries, Clubhouse and more >> Batteries & Chargers >> A123Racing Support >> '5s2p' A123 or '6s2p' A123 pack running 7XL motor
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'5s2p' A123 or '6s2p' A123 pack running 7XL motor - 11/23/2006 10:27:01 PM   
zeropointbug


 

Posts: 7
Joined: 11/22/2006
From: tisdale, SK, CANADA
Status: offline 		Hi,

I just purchased a Quark Monster 125B (the best) controller and a Feigao 540C-7XL motor for a 1/8 scale, 7.2 lb custom project. Anyways, i am struggling to make a choice whether to use a 5s2p A123 custom pack or a 5s2p custom pack. I am building the pack myself from the developer cells. I know that the 7XL can be a current monster if loaded enough, however 7.2 lbs and 1/8 tires are no match for it.

I have worked out from checking out all over the web at discharge curves and from members like 'EveryDayFlyer' thanks for the graphs, they helped; i figured out that in a high drain application like mine, a 6s2p A123 pack should perform modestly better than a 5s Li-Po pack. That is taking into consideration the discharge vdroop and and nominal voltage, and average discharge voltage.

The 7XL has a peak power output of 1500 watts. THe Quark 125B controller can handle 125 amps cont. and 300 amps peak

Li-Po 5s pack with 4.8 Ah capacity and 18.5 volts Nom, should have a corrected 'continuous' power output of 1600 watts @ 16.75 volts. load (96 amps)

An A123 '6s2p' pack with 4.6Ah capacity and 19.8 volts Nom, should have a corrected 'continuous' power output of 2200 watts @15.9 volts load (138 amps)

'5s2p' pack with 4.6Ah capacity and 16.5 volts Nom, should have a corrected 'continuous' power output of 1800 watts @13.25 volts load (138 amps)

So, if any of you guys have any experience with brushless setups, let me know which setup between the two A123 packs.

And if you have discharge data on the A123 cells that differ from what i could find, PLEASE let me know.

THanks

Zeropointbug
       Post #: 1

RE: '5s2p' A123 or '6s2p' A123 pack running 7XL motor - 11/24/2006 3:20:48 AM   
zeropointbug


 

Posts: 7
Joined: 11/22/2006
From: tisdale, SK, CANADA
Status: offline 		Hi

I would like to correct the M1 cell discharge specs: The voltage of the M1 cell once broken in (cell IR decreases) is 2.74 volts at full 30C continuous C rate discharge (70 amps). The discharge curve of the M1 cell is VERY flat, the flattest of any battery in fact, so expect great performance throughout the entire cycle.

6s2p A123 pack is: 2300 watts @ 16.44 volts _ 30C (140 amps)

5s2p A123 pack is: 1900 watts @ 13.7 volts _ 30C (140 amps)

The long pulse for these cells can be up to 80 C ( 1 seconds), thats 184 amps per cell or for this pack thats 368 amps! However, the voltage droop of the cell would be very low, prob around 2 volts or less. This is not a practical way of measuring the cells power ability, more of a safety measure.

I will post another thread with the continuous power capability of all the possible and practical pack assemblies.


Zeropointbug

(in reply to zeropointbug)
       Post #: 2

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All Forums >> Radios, Batteries, Clubhouse and more >> Batteries & Chargers >> A123Racing Support >> '5s2p' A123 or '6s2p' A123 pack running 7XL motor
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