Who using A123 batteries?

[E_ferret]

	Quote: Originally Posted by hybris
	Please post any comments or experience. I am interested in unregulated use on both receiver/servos and ignition.

bought a few A123's a couple of months ago. Put 3s in an electric old-timer (buzzard bombshell), used to fly on 12 NMHs, had to drastically lighthen the tail-end. flew great!
then tried 3s in a combat wing, great duration. Now have a 4s in a Sebart Katana. Due to mounting the wrong Hacker gearbox ,I was pulling 60A,(great verticals!) that fried the 80A Hyperion controller after a few flights, but the A123's were just warm, no problems. As my lipos age, they'll get replaced by A123's.
Charging them at 6A, may try some at 8A.(with temperature sensor attached!) I am using a Hyperion LBA10 charge balancer and a Schulze Lipodimatic in-flight cell monitor set to 2.5V per cell.
My schulze charger cuts-off at 3.65V/cell

[KrisW]

	Quote: Originally Posted by PTS
	Kris - What did you use to check the voltage on the A-123's? I have a new 40% and plan on running the A123 2300ma batts but I want make sure that these batts are up to the task of a 40%. Perry

Perry, I just used a volt meter. It's almost impossible to adequately load the A123's to show a significant voltage drop under load (as you would with Li-Ions), unless you use something capable of handling about 25 amps. Perhaps a small arc welder??

[macanaw]

There seems to be a lot of different assumptions regarding the weight difference on the a123's vs Li-ion. I have the cells from the dewalt packs and here are the weights on a calibrated scale.

a123 4600 mha 2s2p - 10.6
Fromeco 5200 mha 2s2p - 7.2

Difference being 3.4 oz

Add the weight of regulators and your about 1.5 oz difference in weight (depending on what regulators you choose).

Be careful when looking at weights published by manufacturers as they often don't include wires and deans connectors in their published weights.

David

[HuckinChikn]

Well I'm finally in the A123 club! Yesterday I picked up 2 of the 2300 packs.
I cant install them in my katana until i get a charger though.
What chargers are you guys using?

[Scott Gerber]

Cell Pro 4 from FMA Direct, plug and play, charged in less than 40 minutes at the field if you want....


Scott

[KrisW]

	Quote: Originally Posted by macanaw
	There seems to be a lot of different assumptions regarding the weight difference on the a123's vs Li-ion. I have the cells from the dewalt packs and here are the weights on a calibrated scale. a123 4600 mha 2s2p - 10.6 Fromeco 5200 mha 2s2p - 7.2 Difference being 3.4 oz Add the weight of regulators and your about 1.5 oz difference in weight (depending on what regulators you choose). Be careful when looking at weights published by manufacturers as they often don't include wires and deans connectors in their published weights. David

Okay, CURRENT CAPACITY of the packs:

A123 2300 2s2p (4600) 92 amps (20C )
Fromeco 2600 2s2p (5200) 15 amps (3C), 2 packs is 30 amps. . double the weight

Which means that even running TWO of the 5200ma 2s2p packs you still have less current capacity at full draw than a single A123 pack.

So, for a plane that has a max load of 30 amps, you wind up using TWO Fromeco 5200 packs, plus regulators, to supply the power, versus one 2s2p A123 pack.

Let's redo the weights, considering a 30 amp max load:

Single A123 2s2p (4600 ma, 92 Amps max capacity draw). . 10.6 ounces
DUAL Fromeco 2s2p (5200ma, 30 amps max capacity). . 14.4 ounces.

Now addin the dual 1.5 ounce Fromeco regulators for another 3 ounces. . total for Fromeco is about 17.5 ounces versus 10.6 for the A123's, a 7 ounce savings.

Add in the ability of the A123's to be "reborn" after being totally discharged, cost of about $25/pack if you build them yourselves versus $55 or more for the 5200 Fromeco pack (plus $50 reguilator per pack), and you just cut your cost of powering your plane to 25% of what it used to be, at substantial weight savings, while giving it a lot more power to use on demand.

Don't get me wrong, I like the Fromeco stuff. . I have many packs. But as soon as I get another Dewalt battery pack, all my 5200 2s2p's and regulators are going on the shelf. Can';t see a reason to carry the extra weight and complexity, as well as $$$$ in the plane.

[mikedannielle]

	Quote: Originally Posted by HuckinChikn
	Well I'm finally in the A123 club! Yesterday I picked up 2 of the 2300 packs. I cant install them in my katana until i get a charger though. What chargers are you guys using?

Cell Pro 4

[HuckinChikn]

I picked up the A123 racing brand charger. It is too cool seeing my flight batteries
charge in 15 minutes! I do have one concern though...
Like i said, i'm using 2 of the 2300 packs, going through 2 JR heavy duty switches,
and into my two recievers...The leads coming off of the batteries are big thick
like, 12gauge wire i believe, but the JR switches have much smaller wires.
Will i have any problems with current overload or anything? I'm pretty dumb
with that stuff, so I figured I should ask you guys that would know

[Scott Gerber]

The limiting item is the connectors on the switch leads and servos, the wire is heavy enough especially since you have split the load between two receivers.


Scott

[HuckinChikn]

I'm using ultra deans for the connectors So i suppose i will be okay. The JR switches
are temporary, as I have a spektrum 9100 powersafe reciever on order

[Scott Gerber]

I assume you will be using two batteries and the one 9100 receiver (soft switch) when it you get it? If, so you should be good to go with no worries about wires and connectors. Just make sure you check and repair the soft switch as per their online service update....


Scott

[HuckinChikn]

yep, that is my plan. it seemed to be a pretty fool-proof setup, so thats what i'm going to go with I ordered the rx early this week, so it should be here soon.