A MAY

hi guys i am looking for the best batteries i can get , has any one been using the a123 batteries for the receiver and ecu . i would like more ma than 2300ma i will be using dual batteries and switches with a bat share what should i use for the ecu /tems i have a pst 1300r going into a yellow f-15.
thank you
Arden

ravill

My Feedback: (11)

I just switched to 2100 LiPo's from thunder power. No A123's though.

I just got tired of cycling NiCD's. Too many airplanes in the fleet to maintain...

Raf

Vincent

My Feedback: (61)

The two A123`s together would be 4600mah wouldn`t it??

V..

Eddie P

My Feedback: (4)

Just bought some 123's for RX and ECU (Jetcat).

The 2 cell RX packs do not need regulators.

The 3 cell ECU 123 batts need to be setup for a Jetcat ECU as "8 cell Nicad" in the turbine ECU setup menu. Other FADEC's or ECU's of other brands might be able to use a 2 cell, not sure, I just know about Jetcat which is suited for 3 cell 123 packs. This is per Bob at Jetcat by the way, and Jetcat is selling these packs now for ECU's. I personally bought mine from Chad at Sin City Jets.

The reason I went with these batteries is two fold: Standardization on a new "safe" format that holds voltage better under all temperatures and the fact they do not need regulators, making a dual battery RX setup simpler, with fewer failure points. Secondly, the 123 batts can be quick charged easily in 20 minutes. Even though 2300 mah is plenty for RX, you can do a full charge in about 10-15 mins given the fact you'll never dump the pack to begin with. Same goes for the ECU. With a smaller jet engine you can get 5 flights in and then recharge in 10-15 mins for 5 more before you'd ever have to do the same with the RX pack.

The capacity seems more matched to the flights I can reasonably do in a day without having a break of some sort (charge opportunity). The durability, weight, and safety of the chemistry all come into play.

Eddie P

My Feedback: (4)

http://www.rcuniverse.com/forum/m_68...tm.htm#6817119

http://www.rcuniverse.com/forum/m_67...tm.htm#6789732

http://www.rcuniverse.com/forum/m_66...tm.htm#6678643

There has been some talk about how these packs "dump" at the very end of the capacity. As an old electric flight die hard, all I have to say about that is I've always known exactly how much CAPACITY my pack has. I never care about the voltage if I'm checking with a volt meter to "guess" what the pack has left - that is always prone to error because of different loading issues in dynamic flight compared to a static loader or a simple unloaded voltage check So, IOW, I slowly expand my known abilities by how much I'm putting back into the pack at charge. If I know I'm using 70 percent of the pack at 5 flights, I keep flying 5 flights and check the Mah going back into the pack as time goes on. If I notice I'm putting more back in, I fly less before recharging. If you ever get to a lower voltage situation in a Nimh or Nicd battery, you are risking a crash, plain and simple. If you get there in an A123 pack, you will crash. So weather you risk a crash or crash, it's all pretty similar to me. I never stretch it. With the A123's, it doesn't pay to stretch it anyway, you can recharge in 15 minutes. There is no reason to not quick charge with the pack still mounted in the jet.

ALL packs have their pros and cons.

SinCityJets

A MAY, Whether you get your packs from me or someone else, buy A123's. They are the best solution out for both receivers and ECU's.

I am putting together a FAQ for A123's on my site because I field about 15-20 calls a day asking about the batteries. I could almost play a recorder and I don't think they would notice. But here is a little info for you:

They have a 30C nominal discharge and 60C burst (that's 69A and 139A to you and me).
They are as safe as a nicad with a burst better than a lipo. They have a flat discharge curve (6.6v nominal) and maintain voltage until the pack is empty. This is when you will see the infamous cliff dive. Mah per Mah, these packs will last longer than any other chemistry battery. What I mean by that is, a 2300Mah A123 pack will last longer than a 2300Mah nicad/nimh/lipo pack. How could this be?? Because the A123 packs maintain voltage through their discahrge, the amp draw remains constant. In other chemistry packs, the voltage continuously decreases whereby INCREASING the amp draw to maintain the same power (wattage) output.

V x A = Power (watts)

So if your voltage drops, your amperage must increase to maintain the same wattage.

Now, the time extension will probably not be very much longer, I just don't want people thinking that you have to stop using these packs before you would any other pack. I always suggest charging the packs to capacity, flying 2-3 times and then charging to capacity again. This will come up with an average amount of Mah used per flight. Use this figure to establish your cut-off.

Sorry about the tangent.

These batteries also offer a 10 year shelf life, 1000+ cycles, and maintain 95% of their charge over a month's period of time. No more having to top off the morning of going flying. They also do not require regulators for receivers, ECU's, or even gas ignitions. They have about the same voltage as a freshly charged 5 cell Nimh pack. For those absolutely opposed to running their servos over 6 volts (for whatever reason), using a Smart-FLy Batshare brings the voltage down .5 volts.

And the best feature of all, you can charge these cells at up to 10amps (safely)!! The CellPro 4S charges at 4 amps, which will charge a completely dead pack in about 30 minutes. An 8A capable charger will charge it in about 15 minutes. The Orbit Pocketloader (JetCat) is another charger that is A123 capable (with the most current download). And finally, if you don't want to buy ANOTHER new charger, you can use a "dapter" which allows you to use any nicad capable charger to charge your A123's.

If anyone has any questions or requests for special configurations, let me know. You can also purchase 3 cell packs from JetCat and 2 cell packs from Smart-Fly.

Chad
702.521.8010

A MAY

i am thinking the a123 batteries are the way to go you put a charge on the battery after evey 3 flights and you will be ok no diferent than putting air in the tanks for gear etc, after ever flight i can live with that . i have searched several posts but not sure what to use for the ecu for the pst 1300r turbine i would like to use the same type of battery as the a123. has any one used this 9.9 v a123 battery for this turbine. thank you guys for your help.

vincent i was thinking each battery ma on a redundate system total of 9200ma .....ummm that is a lot of ma i have read that a 4300 ma battery only used aprox 830 ma or so for 3 10 min flights

thanks
Arden

SinCityJets

Arden,

I think every three flights is a bit much, but go with what ever makes you feel comfortable. I know the JetCat and Jet Central ECU's can run on 3 cell A123's. The JetCentral can also run on 2 cell A123's. The only difference is the low voltage alarm on the JetCats is currently set too high to allow the use of 2 cells. I am not fmailiar with the PST or who manufactures their ECU.

Chad

Kelly W

My Feedback: (2)

Arden, please see my reply in the PST support forum.
[link=http://www.rcuniverse.com/forum/m_6890499/anchors_6895381/mpage_1/key_/anchor/tm.htm#6895381]link[/link]

You're not likely to get a reply from any customers with experience on this battery and that particular turbine. I've been aware of these packs since SCJ started advertising them, but you are the first to ask me about them. It sounds like the current specs fall in line and the ECU should be able to take it, but there may be increased wear and tear on individual components as a result of the higher voltage.

Kelly

SinCityJets

Kelly,

If you prefer a 7.4v pack, you should just use a 6.6v A123 pack.....unless there is a low voltage warning that turns on around 6.5v.

I have actually had a few customers now ask me about the PST ECU's. It would be nice to know the final answer...

Kelly W

My Feedback: (2)

As I said before, the ECU won't have a problem with it. I've run them on 12V... The rest of the hardware in the overall package may not appreciate the elevated voltage though.

The J600R pack may be a suitable application for the 6.6V pack, since it is less demanding on the starter motor and ECU pack under startup. The 1300R is more demanding (more inertia relative to starter motor size) and may not accelerate from a stop at a suitable rate to satisfy the RPM curve that the ECU is expecting. It may give you a step fail right off the bat...

That's about the best answer I can give without anything to test 1st hand.

Kelly

SinCityJets

Well, if you have successfully run them on 12V, then the 9.9v 3 cell A123 shouldn't be a problem at all. A 2 cell Lipo is 8.4v off the charge.

Good info to know.

Kelly W

My Feedback: (2)

To clarify, I said I have run the ECU on 12 volts. By that I mean the ECU alone with nothing attached to it and certainly not running an engine at the time... In other words, don't take that as an OK from me to start promoting them in another market segment. That's just when I power it up to interface with a PC for programming, and I happen to not have a charged ECU pack around. Normally I program them while running on the stock 7.2 volt pack. I can not guarantee the other hardware attached to the ECU will function properly long term should the voltage be increased. (with the propane solenoid leading the way in my opinion.) I did not design the ECU so I don't know what effect it may have on the RPM board, optional fuel shutoff solenoid, etc. Also of note, as the ECU's driving voltage is increased the resolution of the pump's control decreases. This means a less precise throttle curve, but that's of secondary importance vs. the potential issues spoken of earlier. The highest voltage I have run an engine off was from an 8.4V ni-cad pack.

I'm sure these packs are good products according to the numbers you're promoting them with, but there's an important message here. That is again, these packs are not currently qualified for PST's engines. User's experiencing problems can not expect us to answer 99.999% of any issues brought on by them, nor will any warranty coverage be available should a user damage any part of his/her hardware in experimentation... Its a bit of a hard message, but necessary with untested equipment and technical products.

Kelly

SinCityJets

Kelly, better safe than sorry. Sounds like you should try one out so you can advise your customers. I should probably contact the factory and send them out a pack like I did with JetCat. That way we can get a non-guess answer.

The only two turbines I know for sure work with the A123's are Jet Central and JetCats. I "Assume" the Wrens do too, only because the ECU's are made by the same people that make the JetCentral engines. I will contact Sarah so we can either add them to the OK list or add them to the NO GO list.

Kelly W

My Feedback: (2)

Exactly. Couldn't agree more. I'll send an email off and point them to this thread, advising that they may hear from you. The person you'll probably want to talk with is Kraivuth (B777 on RCU).

Kelly

SinCityJets

Kelly,

If you have a chance, could you forward him my info if I don't get to him first, please.

Chad

timothy thompson

My Feedback: (1)

119 FOR 10 AT HOME DEPOT IN MICHIGAN. GOTTA HAVE A CONTACTOR FRIEND BY THEM FOR YOU TO GET THE PRICE

BalsaBob

My Feedback: (24)

These A123's sure seem to have all the characteristics we are all looking for in batteries. Question ... In a dual A123 battery setup, would regular switch harnesses be used, or, is a special switch harness used ? I have read that regulators are not needed, but is a switch harness with some sort of electronics (diodes ? ) to prevent one pack from draining the other (in the event that one pack fails/shorts) used ? Thanks. Bob

SinCityJets

Bob,

There are a variety of ways to run two (multiple) packs. One is a Smart-Fly BatShare, another is a power expander, and yet another is just running two packs directly to the receiver through two different switches. Youhave just as many options with these batteries as you would any other chemistry battery.

A MAY

chad and kelly, i will be watching this post closely for the good or bad news for the a123 9.9 v battery for the ecu and i imagine there are others wanting to know too. Chad when we get the results i will be gitting the receiver and ecu batteries and charger from scj. And Kelly ,good luck on the battery test

Arden

YLF

My Feedback: (2)

One thing to remember if you want to fast charge your a123 Rx packs is that you will need a heavier lead and connector than the standard "servo plug" and wire which will only allow about 4 amp charge rate.

Also, another option for charging the two cell packs is to use the 6 volt Pb (lead acid) setting on a Triton or similar. The down side is that you will lack about 150 mah of 100% charge since the Pb charge terminates at about 6.9-7.0 volts vs 7.2. But it's a safe way to charge if you're caught without a true a123 charger.

Mike

SinCityJets

Gaspar emailed me regarding the Wren ECU. He stated he felt that the Wren starter motor would not work on 2 cells. His fear with 3 cells was that the kero solenoid might not hold up. He stated the solenoids came in a 6v and 12v flavor, so I am assuming they come stock with a 6v solenoid.

So far we know that Jet Central will work with a 2 cell A123 with no (known) problems, and Jet Cat's will work with a 3-cell A123 if the GSU is set to 8 cell nicad.

I put up an A123 info page for those that may have questions about A123's.

www.sincityjets.com/batteries/a123info.html

I will keep you posted as I learn more.

A MAY

kelly
has there been a test on the a123 battery for the ecu ,waiting for a positive answer maybe use a regulator if its to much

Arden

cactusflyer

My Feedback: (4)

Chad,

I had a conversation with Gaspar about the A123s as well. It seems that know one knows, that is to say, for sure if they will work with the Wrens. I don't use a solenoid valve on the Kero but I checked and determined that the gas valve is rated at 6 volts. In order to learn something, I hooked up a 2-cell a123 pack to my old MKII MW-54 at the field today. The Wren is in in a Boomerang Intro and I have been using a 4600 mah Ni-MH pack for the FADEC. I flew once with the 4600 pack and then I plugged in the A123s. The start went well. It did seem to take a bit longer but the EGT temps were nominal. It was about 62° at the field. I'm curious to see how it would work with warmer ambient temps. I had to fly with the Ni-MH pack though due to CG considerations .......................Bottom line: My Wren will start and run fine with the 6.6 volt A123 pack. I plan on downloading the data from the FADEC to take a look at it.

Tailwinds,

John

Bob_B

My Feedback: (11)

John,
My 44 Gold came from Wren with a 2 cell Lipo for the ECU.
Fully charged this pack is rated at 8.4 volts.
Maybe the newer solenoids are 12 volt versions.
It seems that A123 should be just fine at least for the current motors.
Love that 44!!!