dragon_fire3k

Hi I am getting the AJ Extra 330 with the e-flite power 15 motor and an electrifly 45 amp speed controller and using 2 thunder power 2070 at once. My question is will the speed controller I have be big enough or do I have to run a seperate BEC. Thanks for any help.

mrasmm

the power 15 is rated at 34A cont with a 42A burst, so that esc should be fine for the motor, the BEC on that ESC is rated at 2 amps, I dunno what you need.

Are those 2 3s packs that you are running in parallel?

The motor is rated at 3 to 4s lipo's and the esc is rated the same

http://www.electrifly.com/powersyste...verseries.html

welcome to RCU =)

mrasmm

oh, afterwords I saw that there was a dual 45 ESC, and that one does not have a BEC, so if you have that one, then yes you will have to run a seperate BEC

dragon_fire3k

thanks for the help. I am getting the ESC without the dual battery connections. What would you need to know to know if the 2 amp BEC is enough.

mrasmm

it depends on how many servo's and what tourque they run at. Generally speaking that is enough for 3 or 4 regular sized servos =)

If you are running more than that you will need to get a seperate BEC, or a seperate receiver pack.

hope that helps

dragon_fire3k

I should be good then I am running 4 Hitec HS-81MG's. thanks for the help

dragon_fire3k

New question aobut the electronics. I put my first flight on it today had it in the air for about 2 min when I notice a decrease in power started to bring it down but before I could I had no motor power left and it lost airspeed and crashed. I was running 2 thunder power 2070 batteries and after it came down I checked the volts on the batteries and they both where at 11.64 so what could have made it loose power. It also didnt seem to have the power I thought it would from the start. I could tell from the power it had at the start that it wouldn't be able to hover or do any extreme 3D what could be the problem.

mrasmm

honestly I am not really sure. If those are 3s lipo's and they went down to 11.64v in 2 min, then you have way undersized packs on your plane. A c/13, which most TP's are, if you run the packs full out they should last atleast 4 min and 40 seconds, but at that rate would probably only last 50 cycles or less.

an 11.64v no load reading would be like 40% or so left in the packs. Basically what I think is either they weren't charged all the way to begin with, or for whatever reason your plane is drawing alot more than what those packs are rated for. You should be getting 12.6v to start with.

dragon_fire3k

Yes they are 3 cell batteries. The reason I am using these is because thats what they recommend for batteries with this plane. They recommend the E-flite power 15 with 2 3 cell thunder power batteries in parrell. here is the specs. on the battery. max continuous discharge 25c. sustain discharge 30c. max burst discharge 50c. max continous current 51A. max burst current 103A. 2070 mah. thanks for your help

mrasmm

continuous and sustain discharge are different values? that's kinda weird, I always thought those ment the same thing.

If the batteries were fully charged when you went out and were reading 12.6v, and went down to 11.64v in 2 min, then there is something seriously wrong. If the packs are new, take em back and tell them what happened. You can also read the individual voltages on the cells and see what you get. Sounds to me like you are well within spec and something real weird happened.

dragon_fire3k

I fly with the guys that own our local hobby shop they where there when it crashed. they couldn't figure out anything wrong electrical they think I might of had to small of a prop. I was running a 13 6.5. but that only explanes why it was slow at first not why I lost power completely. so now I have a 14-7 so we will see what happens there. They say 11.64 is still a good charge on the batteries for around 2 min it could have possably been a little longer time seems slow when your in the air but around 2 min. I've got it all back together what kind of ground tests should I do. I think I should just give it full throttle for awhile see what happens if it works fine I just fly it for about 1 min then land see how she does.

dragon_fire3k

Alright I figured it out. The reason it was slow from the start was the prop and the reason it shut off was the Y harness I have for the batteries had a bad connection when I wiggled it, it would turn on and off. the speed controller I have has to be rearmed by giving it full throttle then back to off so when I lost power for a split second the throttle had to be rearmed.

mrasmm

ahh =) good deal =) well not so good that you lost your plane over it, but good deal you found it =)

dragon_fire3k

Well I didnt completly lose the plane I was able to rebuild it. It doesnt look as good but it flys great.

mrasmm

hah, even better =)

GL with your flying

justin castillo

hi everyone i have got a power 15 e-flite motor and i wanted to use two 11.1volt lipos this will make the total volts 22.2 will thsi motor handel that amout of power.

mrasmm

no it will not =)

sounds like you need to learn how to google =) I found this info in about 30 sec or so
http://www.e-fliterc.com/Products/De...odID=EFLM4015A