Poly-Quest 11.1V Lipo Rocks the Super Cub

The Poly-Quest pack arrived earlier this week and this weekend I finally got a chance to install the connectors, charge it up, and take it out for a few flights. Here’s how it all went down…

Initial Charge:
Discharge Details: 4.4A, 3.2V/cell, >600mAh or so (I forgot to look before starting the charge cycle)
Constant Current Charge Time: 2800 seconds (47 minutes) to reach about 1700mAh (77% capacity) at 2.21A, then CV charge cycle begins at 12.602V.
Constant Voltage Charge Time: 1600 seconds to reach 1983mAh at 12.602V
Total Charge Time: 90% capacity in 4400 seconds (1 hour 13 minutes) current was at 0.17A when I stopped it so I could go to bed. It was only dumping in 1mAh every 10-15 seconds and taking longer as the current dropped. I think it calls it done when the current reaches 0.10A. For the first run this should be enough to show off what the pack can do. Anything beyond 80% charged just results in more flight time anyway.

The next day I peaked the pack again, it only took about another 50mAh before beeping, and I dropped it into my Super Cub. It wasn’t the best installation job, it’s basically just floating around inside the cockpit, but as long as it doesn’t fall out it should be fine. I also took this opportunity to replace the cheesy small Tamiya plugs on the ESC/receiver unit with Deans Ultra plugs. The difference here is obvious. I took the plane outside, revved up the motor and gave it a good throw and was completely disappointed. I was expecting gobs of power and it felt like the stock 7-cell 2/3A pack. Actually lately, it’s seemed like it’s been slowing down with every run, it just hasn’t been feeling like it did when I first got it. The motor apparently has been losing its spirit after all these flights, so I bought a new motor. My LHS carries quite a few Park/Hobbyzone parts, so getting a new motor was only $9.99 and even though it says it’s for the P-51D, it has the exact same part/model number printed on the can as the stock Super Cub motor, as well as the same 12-pinion gear. I did a quick kV test on it and measured basically the same thing I did with the original motor, about 2590kV.

Second Charge:
Constant Current Charge Time: 2830 seconds (47 minutes) to reach 1717mAh (78% capacity) at 2.21 amps, peaks at 12.601 then begins CV charge
Constant Voltage Charge Time: 2084 seconds (38 minutes) to reach 2032 mAh (92.3% capacity)
Total charge time to complete: 4914 seconds (1 hour 22 minutes) ending at 12.6V and 0.10A.

It will take several charge/discharge cycles before the pack really starts to charge up to its rated capacity, but it’s no worry, I’m getting some sweet flight times already. I haven’t timed them, but it’s long enough that you almost kinda start to get bored, somewhere between 15 and 20 minutes. But it’s hard to be bored when the plane is flying around at some 40+ MPH with the wind and doing huge, wide-open loops and pulling huge maneuvers with ease. With the new motor and the 3S pack, flying the Super Cub has become fun again! The new P-51D motor made a HUGE difference, the old motor had just had it, but I put a lot of runs on it and brushed motors just wear out (that’s why brushless motors are so great). The difference between the 3S pack and the 8-cell NiMH pack is huge, the plane just pulls so hard through the air. I can do super huge loops, or super tight loops, and even loops where I end up higher in the air after the loop than when I started the loop. I can do death spirals and inverted flight with very little inputs from the Tx. In fact on my third flight I was able to sustain controlled inverted flight for almost 30 seconds. The plane just flies with so much power and authority and it responds almost instantly to my every command. Having the clevises on the longer throw setting helps out with that a lot. The plane is definitely at intermediate skill level now I’d say, at least for still not having ailerons. Maybe that’s the next modification??? We’ll see. I removed the jumper on the receiver unit also, which appears as though it sets the low-voltage cutoff point at 9.0V, the plane was still flying around with tons of power when all of a sudden the prop just stopped and I had to make an emergency immediate landing. Anyway, I’m enjoying my Super Cub and all the crazy speed and power this thing has now.

Third Charge:
Total Charge Time CC/CV: 4902 seconds (1 hour 22 minutes) charged to 2093mAh ended at 12.603VDC and 0.10A. It’s already starting to take more charge.

Stock ESC/Receiver w/FET mod, lithium-polymer pack and stock NiMH pack
Existing plastic carrier removed, now there’s lots of room in there (heatsink was later removed)

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5 Responses to Poly-Quest 11.1V Lipo Rocks the Super Cub

  1. Dave says:


    I’m thinking about going LiPo with my stock Super Cub also. Did you have to make any changes to the electronics to make it work with the LiPo battery? Did you have to mess with the jumper on the receiver at all or does that just add a bit more safety for the life of your battery?

    Also, got a link to the battery and charger you used?

    Thanks for the great writeup!

  2. aktiondan says:

    I pulled out the 1 jumper just above the the connectors for the ATC (which I also removed). This sets the LVC to about 9.0V, which is where you want it for the 3S lipo. With the jumper imstalled I think the LVC is like 6-7VDC, which is way too low for a 3S lipo.

    The charger is the Duratrax Intellipeak Ice, available from most LHS’s or where I got mine, http://www.towerhobbies.com The 3S lipo I bought on sale from http://www.cheapbatterypacks.com for $22. Most 3S packs run about $40, and some of the brand-name ones, TP, can run $60. I wouldn’t know the difference though. This pack runs great, only downside is the motor does get hot, but I tend to run full throttle the whole time I’m flying. I’m sure the lifespan of the motor will be shortened, but it’s well worth the performance!

  3. Dave says:

    Do you think a charger that is cheaper than the Intellipeak will be as effective and safe? I am a little concerned about Lipo fires, having seen some pretty scary videos online of blazing battery packs. I’m really hoping to stay under $100 to go lipo, really under $70 would be best, as I’m also saving for the Spektrum DX6 radio… :)

  4. Dave says:

    Oh, and one more question: What did you do about connectors? Were you able to keep the connectors compatible with the Rx’s current connectors?

  5. aktiondan says:

    I suppose any li-po compatible charger would do. If you don’t need the features of the ICE, then something else should do fine. Just make sure you monitor the pack during every charge, it shouldn’t explode, but I know how you feel, I’m completely paranoid every time I plug it in to charge. So I just watch it the whole time, make sure it doesn’t get too warm.

    I changed out the connectors to Deans Ultras. You can still use the small male Tamiya plugs, but they aren’t very good and after several disconnects they get worse, the sockets open up and don’t make good contact anymore. With more voltage comes more current, and the Deans really deliver and they last forever.

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