Lack of power

[blueskiesdz]

Hi,
I've got an atom 500 stock motor, align 70esc and ar7200bx and have noticed sometimes it has no power from start to finish of flight. The lipo is checked prior to flight and fully charged. Today it wouldn't even fly a big loop without coming out due to loss of power. I've flown again and it's fine with the same type of battery with similar cycles.

Could the esc be causing this problem but I'm confused as its intermittent.


Any ideas please would be really helpful ,


Rik

[Vikki]

Crumbs! Could be anything from a flaky connection up to faulty motor or faulty esc.

If you take the blades off and just run it up does it exhibit the same problems? I ask this because if it does then it's easier to track down in situ. If not then it will likely be visual inspection of each connection and component in the line.

I hope someone on here has had similar and can point a finger straight at it.

[milly0812]

Is it with diff lipos ?

[PKNEC]

It sounds like it's going to be a process of elimination as anyone of the components could have that effect.
Start with the basics of checking all connections.
Then I can only think of removing the blades,paddles etc then bench testing to see if your getting a glitch on the receiver.
Is it doing it with all the batteries or just one?
If you can borrow an esc then test,motor then test,etc you should find the culprit.
sry cant be more helpful

[johnsandywhite]

I have the same problem with my 550FBL with the same age Lipos. 2 are not brilliant and 2 are. They have had quite a bit of flying on them and are only cheapo 30C Zippys. But very happy with them.

[Dave Rand]

I have a similar prob with my 500. And what cures it everytime is running throughout the esc setup mode Inc doing endpoints.

[Vikki]

I have a similar prob with my 500. And what cures it everytime is running throughout the esc setup mode Inc doing endpoints.

Sounds like the esc isn't remembering its setup between batteries.

[cjcj1949]

It is getting colder. Lipos will drop their volts more in cold weather when on load. Try warming them up to between 25 and 30 degrees C. They take along time to warm up, at least an hour. Or I have used internal heating,as advised on here, which is a lot quicker. Practice accurate hovering for a minute. Land for a minute, chance to warm hands, then fly normally. Next buy GensAce 30C from Electriflyer.

[Jamin_00]

It is getting colder. Lipos will drop their volts more in cold weather when on load. Try warming them up to between 25 and 30 degrees C. They take along time to warm up, at least an hour. Or I have used internal heating,as advised on here, which is a lot quicker. Practice accurate hovering for a minute. Land for a minute, chance to warm hands, then fly normally. Next buy GensAce 30C from Electriflyer.

Its not cold enough yet for this too be an issue and even on the coldest days in mid winter I have never had a flight where I have struggled to do a loop!!

First thing I would do is check motor insulation and solder connections on motor, ESC and batts. Then I would look at the ESC.

What brands are all the gear?

[cjcj1949]

It is making a big difference already. It depends on your lipos and how hard you are pushing them.

[Jamin_00]

It is making a big difference already. It depends on your lipos and how hard you are pushing them.

OK, Ive not seen any difference on my flights which are being logged. Everything exactly the same and I'd imagine Im pushing them harder than most?

What packs you using if they are being affected already?

[cjcj1949]

I'm going by measurements of the internal resistance of the packs using a Wane Giles meter. So it shows you how much more the volts are dropping under load. You may not be pushing your setup flat out. That doesn't mean your flying isn't that good, just that your setup is more powerful than you need which is as it should be. You are right that things get worse, but if you monitor the volts drop on your lipos you will find than your flight times will be down by about 20% already. Perhaps your lipos are warm when you use them? If you have a marginal setup it is possible that the temperature is pushing it over the limit. You can get away with a lot with a new 30C lipo in the cold as the Ir is still low. A poor old lipo is a different matter. You may well be right that the cold hasn't made a difference but I like to try the cheapest easiest things first. Testing the Ir with a Wayne Giles meter or estimating it from the change of voltage with charge current is another method.

[blueskiesdz]

As ever cheers for your responses it's much appreciated !!

The batteries are zippy 3000 20c all had about 15 cycles. The motor is the standard atom 1050 kv as an align 70 esc and ar7200bx with align servos. The weird thing is it only does it occasionally and when I increase the power there's nothing left in it !! I have never set the esc up as its been fine and just running the basic factory settings. It's just weird it's ok sometimes and then goes off power.

I did think there might be a glitch in the wiring but there's no noticeable change in the heli apart from the reduced power right from take off. All the kit is only a mth old slid be surprised that the lipos are on the way out already and if the esc is a problem why is it occasionally a problem ???


Very confusing !!!



Rik

[cjcj1949]

It's not weird. Just something we don't understand yet. Helis are very complicated things. Some faults make no difference and some do. Zippy 20C batteries won't be that good. Do you know about the 80% rule? How long do you run them for and how many mah do you take out? It would be useful if you knew how low the volts get on load. If you get a lipo alarm for £2 you can set it to beep at 3.6V. It is possible to destroy lipos very quickly if you use them to their full spec. Testing the lipos would be very useful. Measure the volts under load if you can or buy a good new battery. Extra batteries are always useful. Go for a 30C GensAce or Optipower 30C or Tipple 30C. You may also not be using the motor efficently if your pitch/throttle curve isn't the best. As Vikki said it could be almost anything.

If you are using a 70 amp esc and expecting 60 amps under load your lipos are on the limit of their C rating. I would imagine they get hot. The C rating is based on the lipo not catching fire. You need to be running at half the C rating for them to survive. At high amps a faulty soldered joint will mess things up.

[blueskiesdz]

The lipo's are just warm after use and I fly for 5 mins just mainly sport flying with a bit of soft 3d, they are coming down with around 3.86v in each cell so I think that's the 80% rule ? I may be wrong... . The throttle curve is 0,40,67,83,100 and idle up 1 is 100,85,75,85,100. Too be honest I'm never sure the best throttle curve so any hints would be useful.

What still confuses me is why does it do it on some batteries not others, internal resistance maybe ? I've checked all the wiring tonight and its fine. Maybe as you say 20c lipos are asking a bit much but why is it behaving that way occasionally ?