Hi all, Please tell me how much battery load an 80A ESC can take? If 5000mah 5S 30C lipo can be safely used?

Motor specs are as per HK site
Kv: 580rpm/v
Turns: 5
Resistance: 16
Idle Current: 1.5A
Shaft: 8mm
Weight: 329g
Rated Power: 1580w
ESC: 80A
Cell count: 4~8 Lipoly
Suggested Prop: 12*6, 13*8, 14*7, 15*9

Simple Physics + Math.
Say you 5S Lipo and 80 Amp ESC.

Watt = V * A
        = 18.5 * 80
        =   1480.....................(1)
which is almost peak the motor can deliver.

Now the LiPo must provide 80A (at least in burst)..............(2)

LiPo :  5000mAh 30C 
         5Amp , 30C
So max burst current sustainable by the LiPo is
          5 * 30 =  150Amp ..............................................(3)
Usually LiPos deliver 60% -80% of  Rated C
       
Final  burst current = 150 * 0.6 =  90 ..............................(4)
Now from  (2), 90Amp > 80Amp



Assuming the ESC is rated 5+ LiPos, your setup is good to go.

BTW, what on earth you are planning to airborne with 1500Watts ?

Dear Ujjwaana Sir, Thx for a nicely detailed reply. some questions though

Quote from: ujjwaana on September 14, 2010, 12:51:55 AM
Now the LiPo must provide 80A (at least in burst)..............(2)
LiPo :  5000mAh 30C 
         5Amp , 30C
So max burst current sustainable by the LiPo is
          5 * 30 =  150Amp ..............................................(3)
Usually LiPos deliver 60% -80% of  Rated C

If lipo is delivering 150A, wont it burn my ESC which is 80A only. I use turnigy lipos but i think nanotech lipos will be better. what say?

Quote from: ujjwaana on September 14, 2010, 12:51:55 AM
Assuming the ESC is rated 5+ LiPos, your setup is good to go.

ESC is upto 6S lipo.

Quote from: ujjwaana on September 14, 2010, 12:51:55 AM
BTW, what on earth you are planning to airborne with 1500Watts ?

Please tell if 1500 watts is less or more i need? This setup is for my .46 size high wing trainer which i converted into electric. Test flights are already done with 3S 4400 and 6S 2200mah lipos (using two 3S in parallel and series). the 6S 2200 setup doesn't give much flight time so used 3S 4400. it doubled the flight time but power is low. if there is no wind the plane wont take off which happened today morning so went again for 6S using series cable.
now i want to purchase a 5S lipo 5000mah so it will solve both the problems. longer flight time + more power. if there is a better way please let me know. what will the best battery for this setup? shud be 6S or less/4000-5000mah/20-30C. Thx again

Dear Crazy Pilot,
                      It would be great if you give a cost breakdown that you incurred of the final configuration. This will help in nitro to EP conversion and advantages/disadvantages as YOU experienced. Will be good for the RC community.
Best of luck,
                Rajat Verma

Dear Gp Capt. Sir, Prices are given below.

Motor = 50$ (Turnigy Aerodrive. specs are give in first post.)
ESC   =  75$ (Hobbywing Platinum 80A) Turnigy and HK Esc are also equally good which cost around 40$.
Lipo   =  15$ (for one 3S 2200mah battery. 5S 4000mah is for 45$).

Advantage- no fuss just switch on the power and off you go.
Disadvantage- you have to buy extra batteries if you dont want to wait for next flight.

A decent setup (with 3+ Batteries) would be costing $200. This is just too too much. I would completely agree with Rajat that EP is not economical fro larger setup.  Economies work well till 400-600 sizes (0.25  Glow equi).

For 0.46 and above, Nitro and Gasser work well. A 26cc RCG Gasser from Hobby king would cost you $135. even a 0.46 OS costs little over 6K (ASP ones are lot cheaper). If you add Starter and Glow Lighter, at $200, you would have a decent setup.

As far as 'On the Go' goes, IC engines win. You just need to refuel on the field and not carry lots of battery or do charging on the field.

If you have not already brought the power system, give a second thought. Nitro is messy, but its fun. Gasser are good if you have short supply of nitro-methane in your city.

Quote from: ujjwaana on September 14, 2010, 01:17:55 PM
A decent setup (with 3+ Batteries) would be costing $200. This is just too too much. I would completely agree with Rajat that EP is not economical fro larger setup.  Economies work well till 400-600 sizes (0.25  Glow equi).

For 0.46 and above, Nitro and Gasser work well. A 26cc RCG Gasser from Hobby king would cost you $135. even a 0.46 OS costs little over 6K (ASP ones are lot cheaper). If you add Starter and Glow Lighter, at $200, you would have a decent setup.

As far as 'On the Go' goes, IC engines win. You just need to refuel on the field and not carry lots of battery or do charging on the field.

If you have not already brought the power system, give a second thought. Nitro is messy, but its fun. Gasser are good if you have short supply of nitro-methane in your city.

Dear sir, I already have glow, gas, electric systems. i am tying to switch to EP because of all the mess as u mentioned. HK offers very good rates for electrics so the cost is same or below gas engine.

Found an interesting article on electric. hope this helps--

Here's 18 reasons why electric-powered planes are better than glow-powered planes:

1. Safer - With glow engines, usually an electric starter is used. If not, then a chicken-stick, or worse, flipping the prop by hand. All these methods have hands and fingers close to the rotating propeller. With an electric, there's no need to have your hand near the prop, it's always remote starting. Also, there's no needle valve adjustments required with electric planes, so there's no reason to have fingers near the prop.

2. Cleaner - Since electric planes don't use glow fuel, the plane isn't slimed with oil after each flight. Therefore, a larger variety of finishes can be used with electrics, including non-fuel-resistant paints.

3. Last Longer - Since electric planes don't use glow fuel, the wood doesn't get soaked with oil over time. Therefore, electric planes can last a lot longer than their glow-powered counterparts.

4. Improved Scale Appearance - Since electrics don't have a cylinder head or muffler sticking out, scale subjects can be modeled more scale. Also, since the spinner of an electric plane never needs to be touched by a starter, scale appearance can be enhanced by painting the spinner (olive drab, for example), if the scale subject requires it. A starter would eventually wear the paint away.

5. More aerodynamic - For the same reasons as improved scale appearance, electrics can be built more aerodynamically efficient, since no cylinder or muffler sticks out into the airflow. Electrics with a spinner allow a smooth transition of airflow from the spinner onto the fuselage at all points.

6. Inexpensive to build - The electric planes I'm involved with are small Speed 400 and 05 can motor powered. They don't take much in materials to construct. And since they're smaller, they take less room to store in the garage, and take less room to transport. I don't have to put the plane in the truck bed, it will fit on the seat in the cab next to me.

7. Inexpensive to fly - Electrics can be viewed as less expensive to operate since fuel at $15 or more per gallon doesn't have to be bought, and glow plugs will never burn out.

8. More reliable - There's no needle valves to tweak on electrics. You never have a poor engine run with electrics. You never have an electric motor go lean or rich. For multi-engine electric planes, you never have one motor quit, and the motors always run at the same RPM. Even counter-rotating props are possible with a simple polarity change.

9. More power - Theoretically, you can pump volts (by increasing the number of cells) into an electric motor until it blows apart. With glow engines, they peak at a certain horsepower, and there isn't much you can do to get more.

10. Limited support equipment - When I fly electric, this is the stuff I can leave at home: Field box, almost all tools, bottle of glow fuel, fuel pump, starter battery, power panel, glow starter, engine starter, cleaning spray, paper towels. When I fly electric, all I need is the plane, the transmitter, and the battery charger (which I attach to my car's battery).

11. Quieter - Electric planes are generally much quieter than internal combustion engines, either glow or gasoline. This is increasingly becoming an issue at flying fields. Many clubs must now follow noise level limitations. When people say "The future is electric", they may be right.

12. No emissions - Since fuel isn't burned in an electric motor, there's no emissions released into the environment.

13. Less charging - When I fly glow powered planes, I have to remember to charge the transmitter, receiver pack, glow starter, and starter battery. With electrics, all I have to do is charge the transmitter, since the motor / receiver battery is charged at the field in just a few minutes.

14. Peace of mind - I never have to check the receiver battery in an electric plane. I never have to wonder if I have enough juice left for that last flight of the day. With BEC in electric planes, when battery power is low, the motor will not run, since it conserves what remains and dedicates it to the receiver. Unless I'm flying a glider stuck in a thermal!

15. Indoor Capability - Because electric-powered planes are quieter and have no emissions, they can be flown indoors, and often are.

16. Gearboxes - Electric motors can be fitted with gearboxes of various ratios to make a wider range of propellers available, and to make thrust more efficient. Overall, providing greater versatility.

17. CG Problems - Sometimes glow planes have issues with fuel draw and center of gravity. For example, with a glow pusher you may have CG changes as fuel is consumed, and fuel draw problems if the fuel lines are too long or if the tank is too low. None of this happens with electrics.

18. Multi-engine planes - Electric motors are ideal for multi-engine planes, whether with two, three, four, or more engines. You never have to worry about one engine quitting in flight, you never have to worry about the motors not being "sync'd" (not running at the same RPM). Plus, can you imagine the oil slime caused by FOUR glow engines? And, electric motors spinning in harmony still has a great sound!

Here's a few things that people typically say about electric planes:

"You have to charge it every time." Well, yeah, you have to fill a fuel tank with fuel every time too, right?

"They take too long to charge." Not really. It's probably about as long as it takes to fuel a glow plane and check to make sure everything is still tight, since the glow plane is shaking itself apart from vibration, helped along by a generous oil slime. Besides, if you have several battery packs you can charge one while you're flying the other.

"They don't fly long enough on a charge." How does near an hour flight time sound? This is what you can get with the newer lithium-polymer batteries. How long does the typical glow plane fly? Maybe 10 minutes? Don't you want to land after all that time?

"I don't know enough about them." That part is up to you. If you want to know about them there are many resources available, especially with the popularity explosion of electrics. But if you think ignorance is bliss, then just keep flying glow planes.

"They're not as powerful as glow planes." What BS! Electric planes with brushless motors can hover and perform "3D" aerobatics just like glow planes.

"They're too expensive." Do you want to spend $10 on a good performing electric motor (ferrite Speed 400) or near $100 for a glow engine? But, like everything, you get what you pay for. You could spend thousands on glow or electric - it's your choice. You can buy a GWS Slow Stick kit for about $35 which includes the motor and prop, throw in a little battery pack and ESC, and have a great flying fun plane that can out-perform some glow planes. What do you think about that?

"They're too small, I can't see them to fly them." More BS. Haven't you seen giant-scale electrics?

"Electric planes are just toys." Wake up! What do you think glow planes are?

"Electric planes don't sound realistic." One of many good things about electric planes is that they're relatively quieter than glow planes. That's a strength, not a weakness. In many parts of the world there are noise restrictions, and noise has even shut down some flying sites. Hey, that glow plane doesn't look realistic, it has a big un-scale muffler sticking out the side and it has oil all over it!

"When are you going to quit the electric crap and fly "real" planes?" I'm going to fly "real" planes someday when I pass the FAA exam and get my private pilot's license. Here's a newsflash for you - a model airplane with an internal combustion engine isn't any more "real" than a model airplane with an electric motor!


PS- U havnt answered my questions in post no. 3.

electric all the way.

double power or more compared to nitro