Recommend a battery for this motor/esc combo???
11-16-2009, 08:48 AM
#1
Junior Member
Thread Starter
Join Date: Nov 2009
Location: Collierville, TN
Posts: 5
Likes: 0
Received 0 Likes
on
0 Posts
Recommend a battery for this motor/esc combo???
Hey guys,
Need a little help with a battery selection. Purchased an Ultrafly Frio 10 1050kw/ESC combo on sale from the local hobbyshop yesterday. Figured a combo would be a safe way to get started and havethe right motor and esc pairing. However, I'm starting to question whether the esc is big enough. It's their Apollo 12. According to their instructions, the battery should be a 3S or 10 cell pack. Everything I'm looking at in the 1250 mah range with 3s looks like it needs a bigger speed control.
The setup is going on a 3ch, high wing model I'm converting over from a throttled 049. Very similar to the Lil Rascal in size. All up weight is 16ozwith a wing area around 270sq in. Performance was good enough to do some aerobatics, but really was set up for a sunday afternoon park flyer. Originally was looking at an eflite or super tigre brushless 400 until I saw the combo. I've got a little experience with the electrics and nill with the lipo's so I thought I'd throw this out there. Prop recommendations all seem to be in the 9-6SF range.
Should I ditch the 12 and bump up to the 25 ecs for the bigger battery or do you think a 2S or 900mah battery would be sufficient?
Thanks for the help. Mike
Need a little help with a battery selection. Purchased an Ultrafly Frio 10 1050kw/ESC combo on sale from the local hobbyshop yesterday. Figured a combo would be a safe way to get started and havethe right motor and esc pairing. However, I'm starting to question whether the esc is big enough. It's their Apollo 12. According to their instructions, the battery should be a 3S or 10 cell pack. Everything I'm looking at in the 1250 mah range with 3s looks like it needs a bigger speed control.
The setup is going on a 3ch, high wing model I'm converting over from a throttled 049. Very similar to the Lil Rascal in size. All up weight is 16ozwith a wing area around 270sq in. Performance was good enough to do some aerobatics, but really was set up for a sunday afternoon park flyer. Originally was looking at an eflite or super tigre brushless 400 until I saw the combo. I've got a little experience with the electrics and nill with the lipo's so I thought I'd throw this out there. Prop recommendations all seem to be in the 9-6SF range.
Should I ditch the 12 and bump up to the 25 ecs for the bigger battery or do you think a 2S or 900mah battery would be sufficient?
Thanks for the help. Mike
11-22-2009, 09:28 AM
#2
My Feedback: (4)
Join Date: Jul 2004
Location: Lakeland,
FL
Posts: 7,906
Likes: 0
Received 0 Likes
on
0 Posts
RE: Recommend a battery for this motor/esc combo???
Mike you are a little confused. The battery size does not really determine the esc size. The motor/ prop draw in amps is what determines the esc size and to a point the pack size.
Volts is volts, any 3S or 3 cell lipo will have the same voltage, but the numbers after the cell count are what you need to look at. The higher the first set of numbers is the capacity, or how big of a fuel tank you have. Like this, a 3S1250 is half the capacity of a 3S2500, but still both are the same voltage.
The second set of numbers is the C rating or discharge rating, higher the number the higher the amount of amps the pack can handle. Like this, the 3S2500 lipo at a 10C rating is good for a MAXIMUM of 25 amp draw, same pack at a 20C rating is good for 50 amp draw. Think of the C rating as to how big the fuel hose is for your batteries fuel tank.
Now all that said you need to buy a Watt meter, for electrics it's a must have. Without it you are guesssing what your system is doing, and that can get expensive fast if you guess wrong.
I don't have the Frio motors in my data base so I used a similar spec AXI. According to MotoCalc your set up will pull around 10 amps. Now rule of thumb with lipos is to limit your draws to 80% of the lipo's capability. So you need minimum a 3S1250-10C pack for a bare minimum. The 900 would work but your flight time would be pretty short.
Again according to MotoCalc, with your set up and the 3S1250-10C pack you would get approx 16 oz of thrust, around 36 mph, and 8 minutes flight time.
Also it shows approx 60 watts per pound which is about where you want to be for a trainer.
I'd say this bird will leap off the ground at 1:1 thrust to weight ratio, real close to hover ability, and should do some decent aerobatics, thou it's not going to be very fast.
If you need more speed, drop down to an 8x6 prop from the 9x6. Will drop the thrust a little, will also drop the amp load, but speed will be closer to around 45 mph.
Hope this helps.
Volts is volts, any 3S or 3 cell lipo will have the same voltage, but the numbers after the cell count are what you need to look at. The higher the first set of numbers is the capacity, or how big of a fuel tank you have. Like this, a 3S1250 is half the capacity of a 3S2500, but still both are the same voltage.
The second set of numbers is the C rating or discharge rating, higher the number the higher the amount of amps the pack can handle. Like this, the 3S2500 lipo at a 10C rating is good for a MAXIMUM of 25 amp draw, same pack at a 20C rating is good for 50 amp draw. Think of the C rating as to how big the fuel hose is for your batteries fuel tank.
Now all that said you need to buy a Watt meter, for electrics it's a must have. Without it you are guesssing what your system is doing, and that can get expensive fast if you guess wrong.
I don't have the Frio motors in my data base so I used a similar spec AXI. According to MotoCalc your set up will pull around 10 amps. Now rule of thumb with lipos is to limit your draws to 80% of the lipo's capability. So you need minimum a 3S1250-10C pack for a bare minimum. The 900 would work but your flight time would be pretty short.
Again according to MotoCalc, with your set up and the 3S1250-10C pack you would get approx 16 oz of thrust, around 36 mph, and 8 minutes flight time.
Also it shows approx 60 watts per pound which is about where you want to be for a trainer.
I'd say this bird will leap off the ground at 1:1 thrust to weight ratio, real close to hover ability, and should do some decent aerobatics, thou it's not going to be very fast.
If you need more speed, drop down to an 8x6 prop from the 9x6. Will drop the thrust a little, will also drop the amp load, but speed will be closer to around 45 mph.
Hope this helps.
11-22-2009, 08:45 PM
#3
Junior Member
Thread Starter
Join Date: Nov 2009
Location: Collierville, TN
Posts: 5
Likes: 0
Received 0 Likes
on
0 Posts
RE: Recommend a battery for this motor/esc combo???
Thanks. I've figured out a little more since posting my question and I probable. Your post make me feel like I'm on the right track with the 3s1250mah I just picked up. Waiting on my charger to get here so I can see how the setup works. I'm not worried about it leaping off the ground or a ton of top end speed. The plane is a being converted over from a throttled 049 and was usually flown throttled back and just buzzing aroud low. I'll admit the 3 cell 1250 was bigger than I expected, but shouldn't fit right into the radio compartment.
On another note, being that this is a converted a/c, how much ventilation do I need to add to give the battery and ecs some airflow? I was thinking of cutting some vents in the bottom of the fuse where the fuel tank used to be. I've also opened up the bulkhead between the old tank area and the radio compartment under the wing. Any suggestions as to what I can do to help keep the battery and esc cool?
Mike
On another note, being that this is a converted a/c, how much ventilation do I need to add to give the battery and ecs some airflow? I was thinking of cutting some vents in the bottom of the fuse where the fuel tank used to be. I've also opened up the bulkhead between the old tank area and the radio compartment under the wing. Any suggestions as to what I can do to help keep the battery and esc cool?
Mike
