siclick33

I am considering trying A123 batteries on my next jet. Can anyone tell me if they are 'approved' for use with powerboxes and if anyone knows of any problems doing so?

Secondly, if I use them on my manual Wren 44 ECU I will need to regulate the voltage to, ideally, 4.8v. Which regulators would be suitable for this? I don't think the pump current is too high (max 3 Amps) so am I correct in assuming that any of the 'RX' regulators (such as the duralite) will be ok.

Thanks

Gary Jefferson

My Feedback: (167)

I am running one of the new SC-12 RRS Powerboxes with two of the two cell A123 receiver packs in my F-100. The only difference is that the voltage indicator lights are not accurate since the A123's have a different pack voltage than the Lithium's which are typically used in Powerboxes. Just make sure that you set the voltage dip switches properly on the back of the Powerbox.

I don't know about Wren turbines or what you need but I can tell you that the Fromeco regulators will work with the 2 cell A123's. I have them in my Scorpion.

Gary

siclick33

OK, I have found out that the Powerbox Champion RRS actually has a specific setting for A123 batteries which is quite good. This was a little hard to discover as there still only appears to be a German manual for it.

Does anyone know what the battery requirement for the Powerbox Royal is? The specs on the website say 2 cell Lipo or 5 Cell NiCd/NiMh but the manual only mentions Lipo and does not mention switching battery types. Does anyone know if NiCd is actually an option or, even better, does it have an A123 setting like the Champion RRS?

Eddie P

My Feedback: (4)

Unfortunately Wren hasn't gotten with the program for A123's yet. They are still only good for Nicads or Lipoly. I have a Supersport and I have to use a lipoly ECU pack along side my A123 receiver packs. Not a huge deal, but A123 is clearly the way to go IMHO, and it's nice to be standardized on battery types. My Jetcat powered airplane is 100 percent A123 for radio x2 and ECU X1 pack.

cactusflyer

My Feedback: (4)

Why?

I use a 2-cell A-123 on my old MK II MW-54 and it works fine. The start is a little slower but the temps are nominal. I haven't tried it with my Super Sport yet but I'm sure it would be fine. The starter on the MK II is pretty tired.............45 hours on the engine and it still spins fast enough at A125 voltage to do the job.

Tailwinds,

John

Eddie P

My Feedback: (4)

The essence is that I was told in no uncertain terms by Wren that the A123's, while a good battery, were not supported by the FADEC software specifically and I'd be taking a chance by going that direction. When I asked them when the A123 "mod" would be available, they said they weren't even working on it as A123's were not "mainstream".

A few years ago when I first changed over to A123's - Jetcat simply said, "go for it, just use the nicad programming with the proper voltage". So I did, results were great. And it turns out for some folks, several ECU's fried on an occasional basis (not with me fortunately). Then Jetcat looked into it and offered a "fix". So last fall I sent in my Jetcat ECU for the new "A123 upgrade" and that essentially was a slightly different program to the ECU for the A123 option. No more fried ECU's. I guess I got lucky being an early Beta tester of sorts with Jetcat. As far as going A123 on Wren, it's interesting to see you have had good results being your own Beta tester. Interestingly enough some of the fried ECU's on the Jetcats were reportedly due to starter hangups on "lower voltage". Have you ever had a start fail to engage with the A123? Sounds promising though, thanks for the feedback as I hadn't heard anyone using these with the Wrens yet.

GSR

My Feedback: (145)

Your close- The fix is a hardware change for the JetCat ECU. A larger MOSFet and heat sink are used. The battery type in the menu does nothing unless you use the low battery warning-The operation of the ecu does not change with battery type selection.
There are two different extremes between Jetcat 123 usage and FADEC A123 usage. With the Cat you are going up to 3 cells 10.8/9.9volts (hot/nominal)-hence the fried MosFets on occasion.
With the FADEC you are going down in voltage 2 cells 7.2/6.6volts so you could possibly have some low start voltage issues.
That being said -I had quite a number of runs on my P120 with a 3 cell 123 before I had it upgraded and never had a problem. I have also started my 54MKII a number of times with a 2 cell 123 and have had no problems also.
Scotty

S HARRIS

My Feedback: (6)

Has anybody used a Duralite 5.1 volt regulator with A123 2 cell pack on a Jr 2.4 system. The higher voltage made some servos unhappy. Have installed this set up in my Bandit already. So far works fine. Scott

Mace

My Feedback: (21)

Scott,

What servos are you using? I'm using the Duralite regulator on a lithium pack identical to the Duralites (homebrew). One thing I wanted to mention is when you hook up the A123 to the regulator, note your input voltage and your output voltage UNDER A LOAD. Then determine if you really want to go with the Duralite regulator.

MACE

S HARRIS

My Feedback: (6)

Well guys, I flew this week in at the Miss Afterburner rally and had no issues with the A123/ Duralight 5.1v regulator combination . Really didn't expect any issues since I was already using the same regulator with a 6volt nicad pack in the same jet. Flew 9 flights still charged after 3 but much less charging time which is very good. FWIW Scott

Robrow

My Powerbox switch/regulator works fine with 2x A123's in my Bobcat, but I also did not expect any issues as I've used it with both 2x 6v NiMh and 2x Duralite 7.4v Li Ion.

I just keep the usual careful eye on the mAh consumption per flight and top up accordingly. What I like about these cells is their combination of safety with speed, onboard charging at 4C they don't even get warm and it's so quick, typically <15mins on the deepest top up, they also seem to stay pretty much in balance.

Rob.

Tom Antlfinger

My Feedback: (24)

I am using two different setups with A123....On my Kingcat, I have one 2300 pack going into a Smart-Fly Regulator using 18 ga wire from the pack to the regulator with Dean's Ultra Plug and dual 22 ga wires with JR connectors out to the dual inputs of the 1221, using dual switches. I have the regulator adjusted to 5.5 volts. I am using 8411's all around except 351's on the brake and retract valves and 2721 on the N/G. Works flawlessly.

Re-charge with balancing using the CellPro 4S at 4 amps between flights takes 2-3 minutes without balancing and about 5 minutes with balancing. I use about 350-400 ma/10 minute flight.

On my BVM F-100D, I have dual 2300 A123 packs going into 2 HD switches and then into dual inputs of an Electrodynamics Battery Backer and then two output leads into the dual inputs of the 1221. The internal drop of the Backer is about .6-.7v so voltage ends up at about 5.8-6.0v to the RX.

I have Bennie's ECU settings for a 4S A123 pack for the Pegasus in my Hun and will be upgrading from NiCd shortly.

I have a Wren 160 on my KC, so still have to run Liths or NiCds until Wren sorts out using A123, not currently approved.

Using A123 without a voltage dropper is fine as long as you don't goof if you are using any analog or small digital servos. I did goof, while setting up my Hun for the 1221. Inadvertently, I had one of the slats( 2-3301's) hooked up reverse on my Matchbox and stalled them. I was temporarily using an A123 direct to the RX. That 6.8v fried those stalled 3301's in about 10-15 seconds.

L Turner

My Feedback: (3)

Cactusflyer,

To clarify, is the older '54 Mk II Wren you are powering with A123s a Manual start or Auto Start? The currents passing through the FADEC are likely much higher and more critical with autostart- ECU+Glow plug+solonoids +Starter motor, putting the electronics at risk, while manual start with an external glow, battery&switch should lessen the tendancy to fry the FADEC.

Pehaps we should float these questions with Gaspar, the designer of the Wren FADECs. He is often very helpful.

siclick33

Does anyone know how the power supply distribution varies between the 2 FADEC versions?

The manual start requires the minimum battery voltage possible (whilst still obtaining max RPM) to get the best pump resolution; this typically requires a 4.8v battery. The autostart version uses a 7.2v battery or 2 cell Li-po. Does this mean that the Autostart FADEC has a voltage regulator or does it rely on a poorer pump resolution?

From my understanding, 2 cell A123 is too high a voltage for a manual start engine but too low for the autostart. In the mean time I have gone for a 7.2V Li-Mn.

Gaspar

Have been PM'ed to post in this thread to clarify some things regarding the fadec operation, but you must take in to account that what it counts is the whole system, the success of operation depends on starter, batteries, pump, etc, and here is where the engine manufacturer have the last word.

-In manual start units: You can use any voltage up to 12V. It is recommended to use the minimum possible voltage for smoother running and reliability.
-In Autostart units: The ecu accept any voltage between 6 and 12V. But the ancillary components surely not, if voltage too low maybe the starter would not spin fast in aft for startup, if voltage too high surely the 6V solenoid valves will not be happy, and surely the starter will be overpowered and can overload the ecu if the parameters are not adjusted to suit the new voltage.

I haven't tested, but I think that all wrens can run with 6,6V except the MW44 Autostart that sure that the starter don't spin fast in aft for startup, and will need 9,9V and some tweaking on the parameters and new solenoid valves.

Gaspar