I have 6 CH BlitzRCWorks Fun Scale Flight Trainer RC Trainer Airplane ARF. With a 45amp ESC (Topfire tp-e03-0045), and a 3648 - 600KV brushless outrunner motor

I can't find any info(spec's) on the ESC or the motor. That's after many hours of searching. What I want to do is run a 5S LiPo in it.

Most reviews say this plane fly's great. But is just a little under powered. Instructions say to use 4S.

I'm thinking of using a 5S I'm also thinking I could back off the throttle % a bit. so the max output voltage to the motor is lower than max for 5S, but a little higher than max for a 4S. Like 15.5 volts output. So is this a good idea, or am I going to toast my ESC, and motor like a fool. Oh ya. The radio is a 7ch Futaba

Just a little background for ya. I'm not new to RC planes. I started flying nitro in 1997. I have flown peanut scale to giant scale, and everything in between. But this is my first electric.

I'm thinking of using a 5S I'm also thinking I could back off the throttle % a bit. so the max output voltage to the motor is lower than max for 5S, but a little higher than max for a 4S. Like 15.5 volts output. So is this a good idea, or am I going to toast my ESC, and motor like a fool.

Nope, nope, nope.

Adding a little voltage (one cell's worth) will result in a big change in the current drawn by the motor. Even if the ESC (or more specifically, the BEC inside it that's powering your radio and servos) can handle the additional voltage, it most likely will not be able to cope with the increased current flowing through it and will fry in short order. Same goes for the motor.

You also can't limit the system with reduced throttle. In fact, running lower throttle causes the ESC to heat up MORE than full throttle, and with the added current due to the increased voltage you get even more heat... You see where this is going, no? Side note: A 4S, "14.8V" lipo pack actually charges to a full voltage of 16.8V. Lipo cell voltage is 3.7V nominal and 4.2V full.

There's a solution to an underpowered plane, though: Bigger prop. That's all there is to it. A little bit of an increase in prop size (pitch, diameter, or both) can mean a big increase in performance in the air. You just have to make sure the bigger prop isn't .... too much bigger... because then stuff will fry. If you don't have a wattmeter, get one.

There are more solutions, too, but I'll let you chew on this one for a bit.

Thanks. I was afraid of that. I will be doing prop tests.

Thanks again for the help

I have that same plane. I broke the prop shaft over tightening the prop so I change to a 4250 500kv motor and a 60A ESC for the time being. The plane flies better with the heavier motor. Before it would be flip flopping in the air.

Right now I'm flying mine with a 14x12 prop making about 450 watts @ 32 A. I have a 1000w 860 kv motor I'm gonna put in tonight with a 10x6 prop. According to my test data, it should be making 730 watts with a 10x7 prop on 4S

OK. So we start prop testing. That is bringing up more questions. How do I use a watt meter and what is it telling me?

Originally Posted by gom

OK. So we start prop testing. That is bringing up more questions. How do I use a watt meter and what is it telling me?

You connect the watt meter between your battery and esc. Make sure the plane is restrained and run it to full throttle with the prop on while looking the watt meter. It will tell you how much amps you are pulling and how much watts you are making.

Since the flying weight of the plane is about 5.5 lbs, you need to be making atleast 500 watts to do mild aerobatics. For 3d flying its about 150 watts per pound.

Mine is making about 450 watts. The plane flew fine but it is underpowered

I installed the motor last night and went out this morning. I flew it with a 25c GensAce 3300 mah 4S battery and 11x5.5 prop. It was making 681 watts @ 41A.

I flew for about 5 mins mostly at WOT. Battery came down at 14.75 v

wow sounds like that worked out well. grats man

OK I got another question for ya. what kind of flight time can I expect from a 2200mah batt with this plane. on the stock setup?. Instructions say, and RTF comes with a 3300mah. I can shave about a pound and a half. With the lighter batt

Also tech support got back to finely. This is what they said

Thank you for contacting Banana Hobby. For 2 Bladed props, you can use a 14 X 7 or 15 X 6. Additionally, the manufacturers do not recommend going higher than 4s as anything higher will fry the electronics. If you wish to install a 5s or 6s battery, I recommend changing out the ESC and Motor a stronger ones. Lastly, the voltage input of the stock motor is rated for 4s only. Any higher and the electronics will fry.

Originally Posted by gom

OK I got another question for ya. what kind of flight time can I expect from a 2200mah batt with this plane. on the stock setup?. Instructions say, and RTF comes with a 3300mah. I can shave about a pound and a half. With the lighter batt

Also tech support got back to finely. This is what they said

Thank you for contacting Banana Hobby. For 2 Bladed props, you can use a 14 X 7 or 15 X 6. Additionally, the manufacturers do not recommend going higher than 4s as anything higher will fry the electronics. If you wish to install a 5s or 6s battery, I recommend changing out the ESC and Motor a stronger ones. Lastly, the voltage input of the stock motor is rated for 4s only. Any higher and the electronics will fry.

Depending on how you manage your throttle, you should be getting about 3-4 mins with the stock setup. I think it best if you use a bigger battery which will help it to penetrate the wind plus longer flight times.

THX Yeah that's not going to be long enough. My bro inlaw has the same plane, with the factory batt. Going to test it this weekend to see what kind of flight time we can get from it. That's the one we just finished building. Mine is still in the mail. Should be here in the next day or so. It seems like a great buy for $100.00.