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Here's a new one....

Old 01-21-2013, 12:48 PM
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smcharg
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Default Here's a new one....

OK. This is going to sound crazy but I SWEAR, it's true...


Two weeks ago, I was flying my De Ja Vu and I pushed from inverted to vertical. Half way up the line, the plane cuts off. So, I swing around quickly and head for the runway. On approach, I'm able to "refire" the motor by turning the motor switch off and back on from the transmitter. The motor comes back to life but you can hear it cutting on and off. I land safely and take it to the pits. This was a fully charged 50 flight battery and I was only in the first 1/4 of the sequence.

Since this has happened before on my Passport, I was thinking it was the Anderson Pole arming plug. I removed the plug to look at the metal contacts and the positive side seemed like it was about wore out. Removing the arming plug from the plane and plugging the battery directly into the ESC, I checked again and the problem was gone. I marked it up to the arming plug and used the remaining two batteries to fly the rest of the day without the plug.

Fast-forward to yesterday. I had replaced the Anderson Pole plug with Dean's connectors as they actually handle high voltage much better. I stuck in my Sky Lipo 4400 mah pack and took off, turned downwind and flew out of the box for my turn-around to enter the box and begin the sequence. I pulled vertical and half way up the line, the plane dies again in exactly the same fashion. Needless to say, I was a little beside myself. Once again, no problem getting the plane back to the runway and on to the pits. I thought to myself that maybe I hadn't done a good job wiring although I'm pretty maticulous when it comes to electronics. I had one of the guys hold the plane up vertcially and I ran up the throttle. The first time, everything worked fine but then he did it again and the plane cut off. I checked all my wiring and thought oh boy, now I have to come up with another ESC. I decided to try it again with a different battery pack and could not get it to repeat no matter what I did. I even had the guy shake the airplane with the throttle up and it wouldn't even hesitate. It's the battery! But how...how is this possible? It did this before switching out the arming plug.

It then dawned on me. I had the same pack (1 of 4 packs I have) in it both times this happened. The reason it didn't repeat the first time after removing the arming switch is I didn't use that battery again for the day. When I tested the first time, two weeks ago, I had switched the battery out at the same time I removed the arming switch. Here's where it gets really weird.....

I took that battery and put a volt meter on it. The battery was laying horizontally and the voltage was correct. I, literally, stood the battery up and the voltage started jumping all over the place. I laid it back down on the table and the voltage stabilized and remained. This time, being very careful not to move discharge leads, I stood the battery up again and had the same thing happen! We decided that it was the clunk line in the battery and to discard it as normal.

I can only attribute this to some connection between the cells inside the battery shorting out. It still made very little sense though.....taking a battery (especially in a plane) and changing it from horizontal to vertical should not have this type of thing happen. It seriously was like a stuck clunk in a fuel tank. I guess I"m not really looking for anything since it was just a Sky Lipo as far as answers but it does bring up speculation that you may have fun with. Two things though: A. You get what you pay for (50 flights out of both my Sky Lipo packs and they're dead vs. 125+ flights so far on my F3A Unlimited packs or 300+ from my Hyperions). B. NEVER change two things at the same time when trouble shooting. Yes, I should have known that. I was just certain it was the arming plug since this happened on my Pass-Port a few years ago and the fact the Anderson plug on the positive side looked so worn out. Still, the battery thing makes zero sense especially when strapped down inside the aircraft. I checked for moving wires as well. Just weird I guess.

Old 01-21-2013, 04:22 PM
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Default RE: Here's a new one....

I flew with Sky Lipo Batt. for 1 year same packs never have any problem but I have friends they have Thunder Power BAtt with maybe 75 flights and they are goin bad even expensive batt they go bad the good think is Thunder Power have 2 year warranty and 50% after that for replacement
ORIGINAL: smcharg

OK. This is going to sound crazy but I SWEAR, it's true...


Two weeks ago, I was flying my De Ja Vu and I pushed from inverted to vertical. Half way up the line, the plane cuts off. So, I swing around quickly and head for the runway. On approach, I'm able to ''refire'' the motor by turning the motor switch off and back on from the transmitter. The motor comes back to life but you can hear it cutting on and off. I land safely and take it to the pits. This was a fully charged 50 flight battery and I was only in the first 1/4 of the sequence.

Since this has happened before on my Passport, I was thinking it was the Anderson Pole arming plug. I removed the plug to look at the metal contacts and the positive side seemed like it was about wore out. Removing the arming plug from the plane and plugging the battery directly into the ESC, I checked again and the problem was gone. I marked it up to the arming plug and used the remaining two batteries to fly the rest of the day without the plug.

Fast-forward to yesterday. I had replaced the Anderson Pole plug with Dean's connectors as they actually handle high voltage much better. I stuck in my Sky Lipo 4400 mah pack and took off, turned downwind and flew out of the box for my turn-around to enter the box and begin the sequence. I pulled vertical and half way up the line, the plane dies again in exactly the same fashion. Needless to say, I was a little beside myself. Once again, no problem getting the plane back to the runway and on to the pits. I thought to myself that maybe I hadn't done a good job wiring although I'm pretty maticulous when it comes to electronics. I had one of the guys hold the plane up vertcially and I ran up the throttle. The first time, everything worked fine but then he did it again and the plane cut off. I checked all my wiring and thought oh boy, now I have to come up with another ESC. I decided to try it again with a different battery pack and could not get it to repeat no matter what I did. I even had the guy shake the airplane with the throttle up and it wouldn't even hesitate. It's the battery! But how...how is this possible? It did this before switching out the arming plug.

It then dawned on me. I had the same pack (1 of 4 packs I have) in it both times this happened. The reason it didn't repeat the first time after removing the arming switch is I didn't use that battery again for the day. When I tested the first time, two weeks ago, I had switched the battery out at the same time I removed the arming switch. Here's where it gets really weird.....

I took that battery and put a volt meter on it. The battery was laying horizontally and the voltage was correct. I, literally, stood the battery up and the voltage started jumping all over the place. I laid it back down on the table and the voltage stabilized and remained. This time, being very careful not to move discharge leads, I stood the battery up again and had the same thing happen! We decided that it was the clunk line in the battery and to discard it as normal.

I can only attribute this to some connection between the cells inside the battery shorting out. It still made very little sense though.....taking a battery (especially in a plane) and changing it from horizontal to vertical should not have this type of thing happen. It seriously was like a stuck clunk in a fuel tank. I guess I''m not really looking for anything since it was just a Sky Lipo as far as answers but it does bring up speculation that you may have fun with. Two things though: A. You get what you pay for (50 flights out of both my Sky Lipo packs and they're dead vs. 125+ flights so far on my F3A Unlimited packs or 300+ from my Hyperions). B. NEVER change two things at the same time when trouble shooting. Yes, I should have known that. I was just certain it was the arming plug since this happened on my Pass-Port a few years ago and the fact the Anderson plug on the positive side looked so worn out. Still, the battery thing makes zero sense especially when strapped down inside the aircraft. I checked for moving wires as well. Just weird I guess.

Old 01-21-2013, 05:00 PM
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Default RE: Here's a new one....

I have had similar issues with 2 of the TP5000 10cell bricks in the past.2 separate packs purchased at different times
and experienced sudden loss of power (as in none) in flight. On both occasions I managed to get the plane back safely
and after removing the canopy & with model restrained, working the throttle and moving the battery wires power came
back and sparks came out of the packs.

The packs were retured to TP under warrany and had new wires welded on. I was told that they had a known QC issue.

Simon
Old 01-21-2013, 11:47 PM
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Default RE: Here's a new one....

I've had issues with the plates that the power wires are soldered to delaminating, and causing an intermittent connection. THe wierd thing is it appeared to have delaminated between the base metal of the contact and the solder, which mean it could be stuck back on again.

Thankfully this was for an RC, so I didn't get too upset, and the pack had had a haaard life.
Old 01-22-2013, 08:08 AM
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Default RE: Here's a new one....

Scott, have you checked the pressure pump in the ESC? Could be a bad plunger spring or diaphragm? ;-)

Woodie
Old 01-22-2013, 11:50 AM
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Default RE: Here's a new one....

Could also be balance taps shorting, I have one HK pack that does that, fortunately I caught the problem on my charger, not in my plane.

Peter+
Old 01-22-2013, 12:11 PM
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Default RE: Here's a new one....


ORIGINAL: pvogel

Could also be balance taps shorting, I have one HK pack that does that, fortunately I caught the problem on my charger, not in my plane.

Peter+
So, I actually don't know the answer to this although logic dictates that if there's a short, the short will show itself at all points. But, if the short is in the balance leads and the leads aren't connected to anything in the airplane, can that still affect the discharge lead? Also, let it be known that I charge my batteries in the "vertical" position. Nothing showed on the charger as being bad.

Old 01-22-2013, 03:37 PM
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Default RE: Here's a new one....


ORIGINAL: woodie

Scott, have you checked the pressure pump in the ESC? Could be a bad plunger spring or diaphragm? ;-)

Woodie
I don't think the pump's the problem.

Sound to me like there's a pinhole leak (or something) in the supply wiring and the bubbles are causing an airlock in the pump.
Old 01-22-2013, 04:16 PM
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Default RE: Here's a new one....

I suspect that one or both of your packs are nearing EOL and when you pull vertical the voltage drops under that load to below your LVC. Either that or it's going lean on the uplines.

As for your bench results, there is no explanation that I can think of. I use APP on everything now. Mine are never even warm to the touch in my pattern plane or helicopters.
Old 01-23-2013, 04:15 AM
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ORIGINAL: Silent-AV8R
...I use APP on everything now. Keep in mind that the rating for the APP is 45 amps at 600 volts. So at 42 volts they can handle way more load than what we will ever see. .....
I might be reading that wrong but are you suggesting that APP can hande 45A @600 volts so they should be able to handle more current when used in a lower voltage system ie. 90A @300v or 450A at 60 volts??? If so I'm not sure that's quite how it works...

Old 01-23-2013, 06:29 AM
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Default RE: Here's a new one....

ORIGINAL: bjr_93tz

I might be reading that wrong but are you suggesting that APP can hande 45A @600 volts so they should be able to handle more current when used in a lower voltage system ie. 90A @300v or 450A at 60 volts??? If so I'm not sure that's quite how it works...


The attached shows the APP technical information. It shows that the rating is 45 amps @ 600 volts (unless I read that wrong). The sheet may mean either/or and not <and>. If so, then I'm all wet.

This video also shows the ultimate failure point at 16 volts (it's a heli guy) and 380 amps

http://www.youtube.com/watch?v=QeTTw...layer_embedded

http://www.powerwerx.com/techdata/PP45.pdf
Old 01-23-2013, 06:42 AM
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Default RE: Here's a new one....

Just so it's clear, I am not blaming the connectors at all. I merely noted that the one side of the APP connector at the connection point of the arming plug was worn (I guess I shouldn't say "positive" side since both sides of the arming plug are positive). This would be where the arc would happen as well in the setup so wear is normal. This is why I attributed the initial failure to this. I switched to Deans because this "would have" been the second failure that caused the motor to quit in two airplanes with APP had that been the ultimate cause. The Passport definitely had that as a failure point. The DJV was pretty worn but probably had a little life left. To be honest, I'm not 100% positive I had the Sky Lipo pack in there the first time it failed but fairly certain.
Old 01-23-2013, 08:22 AM
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Default RE: Here's a new one....

Sorry, I was not trying to hijack the thread. Just relating my experience with the APP. As I said above, I think your cells are crapping out under load on up lines. And I have no idea why your bench tests show similar when the cells are vertical.
Old 01-23-2013, 08:28 AM
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Default RE: Here's a new one....

That definitely makes sense. No need to apologize. Most of the time, these conversations lead to new thoughts and answers. Hijack away!

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