Set-up lacking in power......

[Ion01]

I have been using the same ESC, 3 cell lipo, and park400 motor for a couple of years now. I started with it on a ef ultimate fx and had more than enough power! Well, after so long I now have it on a reflection and built it very light using little of the hardware it came with. It is my third reflection so I know what it should fly like. Anyways, I barely have enough power to pull out of a hover! The more I fly the less and less power it has, slowly getting weaker each flight. I know the batteries and the motor won't last forever but how do I know which one to replace? Thanks.

[F3AFlyer7]

Well it can be one of two things.

A: (most likely) you battery is getting weaker.

B: (not likely) something in the motor is going bad causing the motor to drain the battery much faster than normal. This is pretty unlikely because you would notice the speed controller getting much hotter because there would be a big increase in amp draw from the faulty motor part.

What type/specs are your batteries??

[Uncle Brett]

Scott's right, most likely your battery is on its last legs. If you can, hook up a wattmeter and give it full throttle with a fully charged battery, wait about 5 seconds, and see what the meter says. A good battery should not drop below 3.4 volts per cell under load, i.e. a 2s battery not below 6.8 V, a 3s battery not below 10.2 V etc. Lipos have a shelf life, it could be time to replace yours.

[Ion01]

I will get all the details of my set up tonight. I am at work so I don't have it with me. I figure its the battery as the power is unchanging during flight which I would think to mean the max output of the battery is getting less and less. I will also check it out with a wattmeter which should tell me exactly.
Assuming it is the battery, can I send it back to get it "refurbished" or does it just go to the trash? Also, is there a place to buy cheap batteries?

[F3AFlyer7]

About getting it replaced, well it depends on the brand of battery and how well they treat their customers, and how many flights you have on the pack. If you have like 200 or so cycles I doubt anyone is going to replace it. If it's only 50 then you may have a shot.

Also, CHEAP batteries are just another way of not spending money now that is going to cost you in the future. I know the packs are a little more expensive, but if you buy from a well respected company you can assure yourself that they are providing you with the best cells the market has to offer. I would say stick with any of these three: Flightpower, Tanic, TP.

[Uncle Brett]

Lipos can't be refurbished, they will have to be replaced. You can save them to use in a trainer type plane or a plane with a real light wing loading where performance is not the main thing, just circle flying. Once that plane can't get off the ground, then you'll know it's time to throw them away.
There's a lot of places that sell "cheap batteries". If performance and longevity aren't as important to you as the price, then there's quite a few options. Here's a Chinese company that sells cheap lipos (Hextronics) that has been getting mixed reviews http://www.unitedhobbies.com/UNITEDH...6&ParentCat=85
I haven't dealt with this company or used any of their batteries, I'm only going by what I've read.
Up to last year I've spent a lot of money trying to find "cheap" lipos that perform like the premium "expensive" lipos. I haven't been able to. Now, when it comes to lipos I live by the motto: "Buy cheap, buy twice". So now I only buy batteries from Flight Power or Thunder Power. That's just my personal experience and many have had good luck with the cheap batteries.
The main thing that I've figured out over the years to get the most out of my batteries is this: HEAT KILLS LIPOS!
IMO, if after a flight the battery's temp is over 110*F your killing it. We should be able to get well over 200 cycles out of a good quality lipo before it starts to degrade. Here'a a few things that I feel are important to get the max life out of my batteries:
1) Break in new batteries: For the first 3-5 cycles on a new battery never exceed half the battery's continious rating. This can be done either static on a bench in the plane (make sure there's good airflow over the ESC) and using a wattmeter. Or fly the plane with a small prop so at WOT the amp draw is less than half the cont. rating.

2) After the break in, make sure the power system only draws 70-80% of the battery's continious rating. This can be done by propping down or, if you have a specific size prop you want to use, change the gear ratio if you're running an inline gearbox or get a lower Kv motor if it's an outrunner.

3) Try to leave at least 20% juice in the battery after a flight, which translates into 3.7 volts per cell resting (no load). So a 3s lipo should still have 11.1 volts in it after a flight, a 2s lipo should be at 7.4V, a 4s lipo should have 14.8V etc. The reason for this is that when you start drawing the last 20% of the battery's power, this is when the internal resistance of the battery really starts to build up and produce heat. Time your flights, don't wait for the low voltage cut off of your ESC, it will be too late.

4) Good airflow over the battery.

5) Don't store your batteries at full charge for longer than a week. Store them at 50-60% if you're not going to be flying for a while.

Like I said, these are things that work for me and all my points are debatable, but through trail and error I'm now getting the life out of my batteries that I expect.
Sorry about the rambling, I hope this helps.
Brett

[Ion01]

Thanks brett! that is great info! I am using a thunderpower 1320 mah/11.1v 3 cell. I have had it a couple of years and is the only battery I have so it has had a ton of use. Looks like I will be replacing it.

[Matchless]

	Quote:
	5) Don't store your batteries at full charge for longer than a week. Store them at 50-60% if you're not going to be flying for a while.

Brett, that one is a new one for me. What is the line of thought/reasoning behind that suggestion and where did it come from?

[Ion01]

I ran some tests with a voltmeter a couple days ago. All test concerning the battery indicated the battery was good. However, while testing I noticed that when I ran the motor up to higher rpm's the motor began to slightly seperate. Come to find out my problem is that the retainer on the back of the park 400 brushless motor has somehow gone missing. I have emailed e-flite but about getting a replacement washer and retainer but have not recieved a response. Does anyone have any ideas on what I can do?

[F3AFlyer7]

You may be able to find one at a really good hardware store. That's very odd that it is doing that, I would think that the strength of the magnets should hold it together. I doubt E-flite has any of those retainer clips lying around as they probably just get the motors from china, package them, and send them out. I would say call them up and see if you can get a replacement motor.

[Ion01]

The stength of the magnets does keep the motor from just flying apart but at maximum throttle it does begin to seperate to a certain degree. Anyways, I will give them a call and see what I can find out. thanks.

[Ion01]

Just got off the phone with E-flite. They are sending the retainer. As soon as I get it I will test the motor to be sure thats the problem. thanks for all your help guys!