ShellDude

A123 recently sent me an updated Turbo Module in exchange for my old one. I apologize for not having many of the details (A123 is probably updating their documentation) but I was told:

[ul][*] Max Current Capacity Increased[*] Thermal Shutdown logic @ 100C (That's 220F)
[/ul]

Physically, the module looks exactly the same as the old version, but the similarity ends there.

Over the next week I'll be posting individual settings results for running the new module in my HDE 450. For those new to the thread, here are some shots of my project:


I run the following setup:

[ul][*] Himax 2815-3000 Brushless motor w/ 13T pinion[*] Kontronic Jazz 40-6-18 Brushless Electronic Speed Controller[*] 325mm VBlades Main Blades
[/ul]

With this setup using a typical 11.1V 3S Lithium Polymer battery pack (such as a FlightPower EVO20 1800 or a ThunderPower Prolite 2100) I'm able to sustain a headspeed of 2,400 RPM. The AUW for my typical setup is approximately 840 grams.

For new entrants into the Hobby, perhaps one day there will be a 3S pack available out of the box that would fit in a T-Rex minus the turbo module. With the right motor/pinion setup you can get 2,000+ RPM headspeed and easily enjoy 15-20 minute hovering flights with just the plain ol' 3S pack.

I'm sure everyone knows by now that it takes approximately 15-20 minutes to charge these packs with 0 risk of fire or explosion

The rest of this review is for the diehards that like to squeeze all the juice they can from their setups:



The Turbo module isn't for everyone. Your typical 11.1V (3S) Electronic Speed Controller will be unable to handle the voltage output of the Turbo module, even at it's 10.8V setting. If you have an ESC that can handle the output supplied by the Turbo Module (such as a Jazz 40-6-18) A123 allows you to select from one of 4 voltage settings:

[ul][*] 1 Light - 10.8V[*] 2 Lights - 12.0V[*] 3 Lights - 13.2V[*] 4 Lights - 14.4V
[/ul]

All information contained in this thread supercedes any prior claims or observations I've made in regards to this module. A123 may continue to caution against helicopter usage because of all the potential dangers / liabilities and that's their call to make, but I've made it a point to plow forward, independently. In the process A123 has been very receptive to feedback myself and others have provided and have clearly incorporated it into their new module.

In addition to the previously noted upgrades, I noticed the following today from first-hand flying:

[ul][*] Overall Effeciency has been increased[*] Low Voltage termination curve has been dramatically "softened"[*] Unit does a better job overall in deliverying rated voltage based on configured setting
[/ul]

Variable voltage has a price... Most probably already know this, but it's key before getting much farther into exploring my results, that we have a firm understanding of the price you pay. The A123 2300 cell alone delivers a lower nominal voltage than a typical Li* cell. The difference is roughly 1 volt. Those used to running 3 LiPos in series to get a standing voltage of 11.1V will be disappointed to find that a 3S A123 pack provides approximately 9 volts (or a little bit more). Because the A123 cells can handle much higher current demands (and are umpteen times safer than traditional Li*) A123 can convert that extra current into Volts by basically stepping up the voltage. Since the pack is drawing more AMPs to supply the higher voltage, it's mAh rating changes accordingly.

Basically (this list will be updated as I have hard numbers of each setup) it translates as such:

[ul][*] A123 3S Pack (no turbo module) - Delivers 2.3 Amps for one Hour of operation[*] A123 3S Pack turboed at 10.8V - Delivers exactly 1.48 Amps for one Hour of operation[*] A123 3S Pack turboed at 12.0V - Delivers exactly 1.38 Amps for one Hour of operation[*] A123 3S Pack turboed at 13.2V - Delivers approximately 1 Amp for one Hour of operation[*] A123 3S Pack turboed at 14.4V - Delivers approximately .8 Amps for one Hour of operation
[/ul]

Note - All approximations are just that - I have not run thorough tests for all these settings yet with the new module - This section will be updated as I fill in the blanks.

In a T-Rex helicopter a serious flyer can burn through 1.38 amps in about 5-6 minutes. Keep this in mind because running at 14.4 for 3 minutes may not be your cup of tea. But, consider the following for my setup with the turbo module dialed in:

All Quoted Headspeeds are actual numbers measured with an optical tach this afternoon
[ul][*] 10.8V - 1 Light = 2,790 RPM[*] 12.0V - 2 Lights = 2,910 RPM[*] 13.2V - 3 Lights = 3000 RPM[*] 14.4V - 4 Lights = 3210 RPM
[/ul]

First, to dispell the the "there's no way you can get 2,790 RPM at 10.8V when you claim you can only get 2,400 with a traditional 11.1V LiPo." statement The reason is simple. The battery makers and speed control manufacturers have been misleading you. If there's one thing I've learned in following the Li* market, it's full of miscommunication and misrepresentation.

Consider the following charts (shown in a previous thread)


Voltage Cut off Relaxed
One of the biggest benefits I see in the new turbo module is its ability to manage the voltage dropoff much more effectively than the original release. It's almost as if it's acting pro-actively watching the voltage drop in preparation for the ultimate drop. I bet they've got some sweet assembly code managing that trend, and it appears to be working very effectively.



So long as you can handle the extra weight (mine comes in at a a hefty 954 grams) A123 can deliver on their promise for variable voltage which translates to on the fly variable Headspeed for us heli addicts.


I flew my T-Rex today at 3,200 RPM with a Himax 2815-3000 motor and a 13T pinion.... How many folks can claim that?

ShellDude

10.8V Flight Data

Measured 0 pitch Main Blade Headspeed: 2,790 RPM


Ambient temperature outside was 55.9F.

ShellDude

12V Flight Data

Measured 0 Pitch Headspeed: 2,910 RPM




Note: It was a mere 55F here today.

ShellDude

13.2V Flight Data

Measured 0 pitch Main Blade Headspeed: 3,000 RPM

Reserved for additional 13.2V Results

ShellDude

14.4V Flight Data

Measured 0 pitch Main Blade Headspeed: 3,200 RPM


Reserved for additional 14.4V Results

ShellDude

Added 10.8V setting data.

SS Pede

Very cool. I'm a little unclear on how "new" this thing is though. Among car/truck users, there has been a bit of disappointment regarding the turbo module's low current capacity (like with a BL motor). The performance of powerful setups is blunted by the turbo module. Seeing as your first testing post was early this month, I'm not sure if this update is new enough to have slipped by the first people to try these batts. In other words, people may already be running the updated model and are still disappointed. Do you have any thoughts? Perhaps you have had better luck because you are using the turbo in an aircraft? Oh by the way, what is the new current capacity? More than 20 amps? The website doesn't seem to be updated.

ShellDude

I wasn't given any specifics... Perhaps A123 can weigh in.

modifyit15

My Feedback: (27)

can you run the turbo packs in SERIES

richti

Hello shelldude,

I suggest you forget the turbo module and add another cell instead. In that case, you even save 10 g in weight. This will give you around 11,5 Volts at 20 amps. Next you select the pinion to provide the desired blade speed (3200) at that voltage. Then you program the Heli-Mode at your Jazz-Controller. In Heli-Mode the controller will keep the blade speed constant, independent of load or voltage drop. While the turbo module keeps the voltage konstant, the controller keeps the motor revs constant, which at last is the same.
Without the turbo module and the increase in voltage of the accupack the overall efficiency will increase and your flighttime will be remarkably longer at the same performance level.
Over and above, one additional cell costs less than the turbo module.
Please let us know, how it worked out.
We fly a Belt CP from E-Sky with 4 cells and get flighttimes from 8 to 13 Minutes depending on style. With the factory set-up we have a blade speed of 2750 rpm. From your data I see that your average amps are around 15. That would result in a flighttime of almost 9 minutes.

Kraeuterbutter

governor works not the same, it would work better..

because: even if the voltage can be kept at the exact same level during the whole flight,
the motor would not keep same rpm at different loads !

so: to get a solid rpm you NEED to use the governormode at your controller
without gov.mode the turbo-module can only make things a little better, but will not solve the problem

are there any measurances about the efficience of this module ?
how many energy is lost ?!?

i think, adding enough cells would always be a better solution when it comes to power, runtime and efficience.

everydayflyer

Post #1 shows how much run time is lost using the Turbo Module.

A123 3S Pack (no turbo module) - Delivers 2.3 Amps for one Hour of operation

A123 3S Pack turboed at 10.8V - Delivers exactly 1.48 Amps for one Hour of operation

A123 3S Pack turboed at 12.0V - Delivers exactly 1.38 Amps for one Hour of operation

A123 3S Pack turboed at 13.2V - Delivers approximately 1 Amp for one Hour of operation

A123 3S Pack turboed at 14.4V - Delivers approximately .8 Amps for one Hour of operation

Charles

richti

From that data I calculate an efficiency of the turbo module of
- 80 % at 12.0 V (Wh)
- 56 % at 14.4 V (Wh)
In the later case 44 % of the Wh of the accupack are turned into heat.
I think this underlines kraeterbutters and my point of view.

everydayflyer

You would have to measure the difference in delivered power (watts) also. Running the power system at a higher voltage more than likely means higher amps. and more watts.
It takes more capacity from the battery to do this.
The voltage step up circuites in chargers do exactly the same thing. If you are charging a 3S A123 battery using a 12V source for the charger then charging at 10A takes approx. 10A from the source however if you are charging a 6S it takes more than 20 A from the source. You can not get something for nothing.


Charles