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Old May 01, 2008, 01:51 PM
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just bought my first electric motor setup...need advice

I just bought my first electric motor setup and need advice on batteries and charger. I am sure this will not be my last electric, since the performance of electrics now excedes the glow power/weight era.

I purchased the electric motor (4014T-570 14/570)
and Airboss 80 amp speed controller from Extreme Flight RC. It will be installed in a OMP Boxer at around 4.5-5 lbs using a 5 cell pack.

So the question is, should I use Lipo, or jump to the A123 batteries?
I want to go to the A123 batteries, but I know nothing about them, and can one even get a 5 cell A123?

I want to buy the charger that has the most functions and will charge multiple packs at the same time. I saw the Fromeco cube, and it will charge up to five packs, but I don't know if it will charge five, 5 cell packs.

I don't mind spending extra to get what I want. In fact, most of my glow stuff is gonna go away now so I would rather pick a battery type and stay with it.



thanks, Gordon
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Old May 01, 2008, 02:16 PM
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Letchworth, Great Britain (UK)
Joined Jul 2004
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I'm not familiar with your motor or model, but I've been using A123 now for a couple of years in various models ranging from TwinStar II up to my e-conversion of a SIG Liberty Sport bipe.

The Liberty Sport weight 6lbs ready to fly, and uses 6S A123 at 44A to give 870 watts (calculated using nominal battery voltage).

I also have a Flair Magnatilla at 5lbs ready to fly, using 5S A123 at 36A to give 594 watts nominal.

I fly both models for 8 minutes, with usually about 20% in reserve when I land.

I started out buying single cells from a couple of US sources. But lately I've been buying DeWalt 36v packs on the internet, and harvesting the cells. You get 10 A123 cells in the 36v pack. There's a thread here about disassembling the pack http://www.rcgroups.com/forums/showthread.php?t=587606

Can't help you with a multiple-pack charger, but I use a Hyperion 1210i which has an A123 program and charges one pack at a time.
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Old May 01, 2008, 02:46 PM
Joined Jan 2004
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I have been flying 5S A123's in my Extreme Flight Yak for a year. I also use Lipo's as well. I make my own packs from Dewalt packs from Ebay.

As for chargers, I personally use the Bantam e-Station BC6-10. 200 watts, 6S limit, 10 amp charge rate.

The only serious 2 port charger is the Hyperion Duo. Downside is that it requires 15V PS or higher to get the 180 watts. We sell them too. 13.8V power supply power is slightly less. But is it is 2 chargers in 1 box.
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Old May 01, 2008, 02:57 PM
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A123 only for custom hi-performance users, so, do U know how to SOLDER ?
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Old May 01, 2008, 03:43 PM
Southern Pride
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Haralson County GA. USA
Joined Oct 2004
34,839 Posts
Quote:
Originally Posted by hall woo
A123 only for custom hi-performance users, so, do U know how to SOLDER ?
hall there are many vendors who build A123 packs most any way one desires.
Battlepacks.com , Cheapbatterypacks, BigeRC,Maxamps to name a gfew and MRC has them in prassembled SPT (solderless power tubes) and a great price by th e way.


Charles
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Old May 01, 2008, 03:52 PM
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Quote:
Originally Posted by abenn
I'm not familiar with your motor or model, but I've been using A123 now for a couple of years in various models ranging from TwinStar II up to my e-conversion of a SIG Liberty Sport bipe.

The Liberty Sport weight 6lbs ready to fly, and uses 6S A123 at 44A to give 870 watts (calculated using nominal battery voltage).

I also have a Flair Magnatilla at 5lbs ready to fly, using 5S A123 at 36A to give 594 watts nominal.

I fly both models for 8 minutes, with usually about 20% in reserve when I land.

I started out buying single cells from a couple of US sources. But lately I've been buying DeWalt 36v packs on the internet, and harvesting the cells. You get 10 A123 cells in the 36v pack. There's a thread here about disassembling the pack http://www.rcgroups.com/forums/showthread.php?t=587606

Can't help you with a multiple-pack charger, but I use a Hyperion 1210i which has an A123 program and charges one pack at a time.
How long to charge a pack?
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Old May 01, 2008, 06:20 PM
Southern Pride
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Haralson County GA. USA
Joined Oct 2004
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I have a heavy left thumb and tend to use more power than needed.
The heaviest plane I fly is a Sig Fazer converted to electric. It has an AXI 2826-12 ,APC 13X6.5E prop and 70 amp. ESC ,550 watts and better perfomance than when it had an OS FX .46 with tuned pipe.. I fly it on 5S A123 2300 mAh ( DeWalt cells). Auw is 4 1/2 pounds and I get 6 min. flights. I charge the battery with a Thunder Power 1010C at 10 amps. and it takes 13-15 minutes.


Here is a Thread with some A123 fueled aircraft in it.

http://www.rcgroups.com/forums/showthread.php?t=734064

Charles
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Old May 02, 2008, 01:49 AM
T2H
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France
Joined Aug 2007
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I have the same power setup: torque revolution + airboss 80A, the prop is an APC 15x8E. The plane is an Extreme Flight Extra 300 58" which will be finished this week-end

I bought two LiPo packs for this (flightpower EVO 25 3700mAh 5s1p) so it is a standard recommended setup.

For now I have no charger compliant with >5s so I decided to begin with LiPo but I am also considering A123 when my LiPo will be old.

From what I read, this power setup is OK for 10min flight with a 15x8E and 3700LiPo. My only concern with A123 is the ability to keep the airboss BEC operational. I think that 6s A123 should be OK because the voltage overhead over 5s LiPo is low (21,5 vs. 21V with 4.2V and 3.6V/cell respectively).
Maybe the A123 6s will need to prop down a little (14x7E?) but only the wattmeter can be the judge here.
If LiPo 3700 gives 10min (with some safety margin) we can expect to get a good 5min with 6s1p A123 setup providing the same current about 65/70A. The problem is that I will need a new and big charger for this usage but as I am 100% electric now I will get one someday.
Weight is not an issue. My 3700LiPO is 480g (<17oz) and 6s1p A123 should be about 450g (<16oz). With 2 or 3 of these A123 packs, a >200W charger and the ability to plug the power supply at the field then it looks like a perfect setup.

Thomas
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Old May 02, 2008, 02:42 AM
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Letchworth, Great Britain (UK)
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Quote:
Originally Posted by gordyd4
How long to charge a pack?
I charge when I get home, at 1C rate, so it takes 50 to 60 minutes

But if you check out the A123 threads here you'll see that others are charging at much higher rates in the field.
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