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Old Jan 01, 2013, 08:52 PM
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I used two Zippy 3 cell 1600 20C for the static tests. I ran the first one until I noticed a power loss and switched to the second one. Come to think of it, I noticed the RPM problem after switching to the second battery. Also, I didn't know about not storing fully charged LiPo's and charged them when I got them about 3 weeks ago. Another thought: Could I have changed the throttle limit range by accident when changing batteries?
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Old Jan 01, 2013, 08:59 PM
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Originally Posted by delcie70 View Post
I used two Zippy 3 cell 1600 20C for the static tests. I ran the first one until I noticed a power loss and switched to the second one. Come to think of it, I noticed the RPM problem after switching to the second battery. Also, I didn't know about not storing fully charged LiPo's and charged them when I got them about 3 weeks ago. Another thought: Could I have changed the throttle limit range by accident when changing batteries?
If you have problems with throttle range, the easy solution is to wait a few seconds until the esc beeps after plugging in the battery. Don't move the throttle until it beeps.
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Old Jan 01, 2013, 09:30 PM
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If you have problems with throttle range, the easy solution is to wait a few seconds until the esc beeps after plugging in the battery. Don't move the throttle until it beeps
I just tried another test using a Zippy 3 cell 2200 25C battery and did as you suggested. Again, RPMs increased to maybe 70% of throttle range. No increase in RPM from there to WOT. However, judging from how hard the plane is to hold, the thrust may be at max for the motor at the 70& position. Is that possible?
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Old Jan 01, 2013, 10:01 PM
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Originally Posted by delcie70 View Post
I just tried another test using a Zippy 3 cell 2200 25C battery and did as you suggested. Again, RPMs increased to maybe 70% of throttle range. No increase in RPM from there to WOT. However, judging from how hard the plane is to hold, the thrust may be at max for the motor at the 70& position. Is that possible?
Since that didn't work, look up the manual for your esc and follow the steps to set the full throttle range. On the turnigy plush, dys, or any similar escs you usually plug in the battery while the throttle is at full and wait for two beeps. Then you move the stick down and the process is complete after a few more beeps.
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Old Jan 01, 2013, 10:27 PM
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Since that didn't work, look up the manual for your esc and follow the steps to set the full throttle range. On the turnigy plush, dys, or any similar escs you usually plug in the battery while the throttle is at full and wait for two beeps. Then you move the stick down and the process is complete after a few more beeps.
I turns out that the Dynam ESCs work the same way. I followed the instructions and I now have a full range throttle movement. Thanks for the help.

I am going to call it a night.

DLC
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Old Jan 01, 2013, 10:38 PM
Firepower
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Originally Posted by delcie70 View Post
I used two Zippy 3 cell 1600 20C for the static tests. I ran the first one until I noticed a power loss and switched to the second one. Come to think of it, I noticed the RPM problem after switching to the second battery. Also, I didn't know about not storing fully charged LiPo's and charged them when I got them about 3 weeks ago. Another thought: Could I have changed the throttle limit range by accident when changing batteries?
Here is how to do the throttle range but you only have to do it once as he is doing a multicopter with lots of speed controllers.
Throttle Range Setting (3 min 4 sec)


I have about 50 lipos and I keep mine charged all the time. I can go a month or more without using them and some even a lot longer. Maybe I am hurting them but I like to keep them ready just in case.

I fly my AXN nearly every time I go flying and I have not changed the servos. I changed the esc because I had a problem but turned out to be a c of g problem. Mine is an older one so I suspect the ESC and servos in the new ones are better and do not need changing.

I have never used mounting foam tape for my servos but if it is moving put some fiber glass tape over the servo and the bottom of the wing. You are brave just relying on the foam tape. Always good to put the fiber glass tape over the servo just to make sure you do not have problems.

You say "I tested the new ESC by running the motor at WOT for just a few minutes. (less than 5)" I guess that was in the air. I am not brave enough to do any at wot for more than two seconds on the ground to get a reading on the watt meter.
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Old Jan 01, 2013, 10:41 PM
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At least with the Turnigy Accucel 6 charger, you can put your lipos in storage mode to keep them from degrading.
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Old Jan 01, 2013, 10:56 PM
Firepower
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At least with the Turnigy Accucel 6 charger, you can put your lipos in storage mode to keep them from degrading.
I have three Turnigy Accucel 6 chargers and one Turnigy Accucel 8 charger but have never know anything about how long is too long before putting them in storage.

I have some good new big lipos so should look after them.
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Old Jan 01, 2013, 11:04 PM
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I have three Turnigy Accucel 6 chargers and one Turnigy Accucel 8 charger but have never know anything about how long is too long before putting them in storage.

I have some good new big lipos so should look after them.
Bruce from rcmodelreviews/xjet says that he puts his lipos into storage charge if they won't be used for more than a few days.
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Old Jan 01, 2013, 11:13 PM
Firepower
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Originally Posted by kovs View Post
Bruce from rcmodelreviews/xjet says that he puts his lipos into storage charge if they won't be used for more than a few days.
That sounds all right if you only have a few batteries. Just counted over 50 lipos not counting all the 1s lipos.

I'll look into it a bit more.

Thanks
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Old Jan 01, 2013, 11:24 PM
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That sounds all right if you only have a few batteries. Just counted over 50 lipos not counting all the 1s lipos.

I'll look into it a bit more.

Thanks
This might be the video I got that info from, but it could be from another video that he made about the accucel 6.

How to charge a lipo battery using a 4-button charger (17 min 8 sec)
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Old Jan 02, 2013, 05:07 AM
Firepower
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Originally Posted by kovs View Post
This might be the video I got that info from, but it could be from another video that he made about the accucel 6.

http://www.youtube.com/watch?v=kvr-25yGeVk
I'll check the video out after tea. Just been flying gliders on a local cliff this afternoon with a bloke who says he puts his lipos in storage if not being used for two or three weeks. Guess he should know a bit as he flies helicopters for a living and works in their factory in Singapore.

Some people have good jobs. I'll have to check out his heli videos on youtube.


EDIT: He is not bad. Some people can fly planes and helis great. Gavin Broadbent has dozens of videos on youtube about helicopters. Just put his name in youtube if you are into helicopters. Guess he would need to know about LiPos from flying the electric helicopters.
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Old Jan 02, 2013, 07:28 AM
Firepower
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Originally Posted by kovs View Post
This might be the video I got that info from, but it could be from another video that he made about the accucel 6.

http://www.youtube.com/watch?v=kvr-25yGeVk
Just watched the video and will have to go and put my big new LiPos on storage.

I have noticed some of my good LiPos have gone puffy after a while and I had not over discharged them or discharged them too fast. My 5800mah I have only been using on low current draw in my FPV base station has gone puffy because I did not put it into storage.

I usually fully charge my LiPos after using them. Guess I only need to charge my 3S LiPos to about 11.1v.

Thanks again.
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Old Jan 02, 2013, 08:42 AM
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My understanding is that the lifespan of LiPos is shortened by:
- usage (they all have a limited number of cycles in them)
- age (their capacity slowly decreases over time)
- charging above 4.2V/cell (this is unusual, as all LiPo chargers stop at that voltage)
- charging at high C ratings (especially if you go above and beyond their advertised rating)
- let their voltage drop too low (you will hear all sort of theories here, with numbers ranging from 2.9 to 3.3V/cell)
- store them fully charged (best would be to store them at about 3.8V/cell, most chargers have this ability)
- store them in warm places (apparently if you store them near freezing temperatures they lose a minimal fraction of their capacity)

Now, which ones of these factors has the biggest impact I do not know, but back then I contacted Outrage (NRG LiPo batteries) and they told me that leaving them fully charged for long periods of time is probably the worst thing you can do.
As a confirmation that this is at least something to avoid, Apple tells you that if you store your iSomething for long periods, it's better to do it with the battery charged between 50 and 75%, not 100%.

Based on the above, my personal recipe for long battery life is as follows:
- unless I'm in a hurry, charge them at 1 or 2C
- time my flights so that the resting voltage is around 3.7V/cell (I find this a better method, than the famous 80% capacity rule)
- store them partially discharged (as said, 3.7V/cell) and charge them only before using them
- store them in a cool place

Just to be clear, I do not have any hard evidence that this method is better than others, it's just my semi-educated guess.
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Old Jan 02, 2013, 11:16 AM
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Thanks to everyone who responded to my first post.

Quote:
I have never used mounting foam tape for my servos but if it is moving put some fiber glass tape over the servo and the bottom of the wing. You are brave just relying on the foam tape. Always good to put the fiber glass tape over the servo just to make sure you do not have problems.
I didn't change the wing servos; I changed the rudder and elevator servos in the fuse and stuck them to the inside of the fuse with double sided tape... Those are the servos that are moving.

Quote:
You say "I tested the new ESC by running the motor at WOT for just a few minutes. (less than 5)" I guess that was in the air. I am not brave enough to do any at wot for more than two seconds on the ground to get a reading on the watt meter.
I guess I made a newbie mistake.... No, I didn't test the new ESC in the air. I held the fuse in my hand with the ESC and battery just laying on the bench. That might explain why the ESC got hot. (no air flow over it), but why did the motor get almost too hot to hold?

Wait a minute: I think I just thought of the answer to my own question. By holding the plane while running at WOT the motor is really pulling more amps because of increased air resistance because it is not moving forward. The prop has to pull static air through it instead of cutting through the air. Relative wind, etc,etc. Also, in a static situation, a tractor motor would be somewhat cooled by it's own prop wash while a pusher motor doesn't have much movement of air around it. Make sense?

DLC
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