I have the power module, but the voltage of the battery keeps going up and down non stop. Every second its different. One second 11 volts, the other 10.6, the other 11.1 and so on. My quad did 2 landings because of low battery when i have set it to 3.5/cell and the voltage was 3.75. But because of the up and downs it decided to land. Why is that?

Views: 536

Reply to This

Replies to This Discussion

How many users does this forum has? This is the third time i post a topic with 0 reply. Letter from a dead man...

You can change another 3S Lipo battery and test if everything goes well, if the voltage still going up and time, maybe the question is your quad.

I tested it with 2 batteries. I have battery monitor connected on the side and its stable. Can it be bad power module?

Diven Parker said:

You can change another 3S Lipo battery and test if everything goes well, if the voltage still going up and time, maybe the question is your quad.

As my batteries get old the internal resistance of them go way up.  So when I fly the voltage is all over the place.

I try not to push it as this will cause it to go below fail save and Land.

Otherwise you have too small a battery as the unit is drawing more power than the battery or wires can handle.

Also motor feed back could be an issue.

I have rctimer 5010 motors with 17 inch propellers, 10000 mah 3s battery. The current is 11 A at hover and 15A at flight. Im uploading the graph of the battery voltage

Attachments:

I have a new build that this is happening too (voltage fluctuating 1.5 to 2 volts)... my 4 other quads do not fluctuate as much as the new build is doing, so I am inclined to think the power module I am using is the culprit.  I have not used this power module before and have to list it as 'other' on the Battery Monitor setup page.  I typically use the Atto or 3DR power module.  The new power module was ordered on Amazon and I don't remember what brand (if it had a brand).  If interested, I'll post my finding if I swap it out.

If you do so, pls post the results.

TechSully said:

I have a new build that this is happening too (voltage fluctuating 1.5 to 2 volts)... my 4 other quads do not fluctuate as much as the new build is doing, so I am inclined to think the power module I am using is the culprit.  I have not used this power module before and have to list it as 'other' on the Battery Monitor setup page.  I typically use the Atto or 3DR power module.  The new power module was ordered on Amazon and I don't remember what brand (if it had a brand).  If interested, I'll post my finding if I swap it out.

This is normal.

The minimum voltage is under load.  As you raise your throttle the current or Amperage increases, this causes the voltage to lag, or go lower.  How much lower?  That's individual.  I'm accustomed to seeing .5v to 1.5v lower when drawing current.  As the amperage go's up the voltage go's down.  It's not uncommon to damage the lipo batteries be running the voltage down to far.  Only a very short time ,like seconds, under load, below 3v/cell will damage your battery, by a 20% reduction in capacity, or potentially make it a brick.

Voltage lag is serious,  as a demonstration, watch your voltage, or have someone else stare at the display as you power up and take off.  The voltage will dip significantly.  Land and disarm, the voltage comes back up by the amount of lag.

Current never stops changing, so the voltage is responding

Thats is true and also not true. True that the current never stops changing. Also true that the voltage drops under load, BUT when it drops, its constant in the range of 0.2 Volts and it does not change every second. In my case the voltage is all over the place in the range of 0.6 - dropping from 11.1 to 10.5, then 11 and so on and thats every second. Thats not normal.  My pixhawk did 2 landings becasue of low voltage protection, when i was flying for only 5 min and the voltage was 11.4 when landed. Since i disabled this option, there is no problem and i fly for 20 min.

There are hundereds of videos in youtube where you can see that the Voltage is almost constant under load, not like mine. I will post just 2 to see

https://www.youtube.com/watch?v=CKy8SJgK5dQ

https://www.youtube.com/watch?v=SFb3A6MqPcY&t=35s

Harry Courter said:

This is normal.

The minimum voltage is under load.  As you raise your throttle the current or Amperage increases, this causes the voltage to lag, or go lower.  How much lower?  That's individual.  I'm accustomed to seeing .5v to 1.5v lower when drawing current.  As the amperage go's up the voltage go's down.  It's not uncommon to damage the lipo batteries be running the voltage down to far.  Only a very short time ,like seconds, under load, below 3v/cell will damage your battery, by a 20% reduction in capacity, or potentially make it a brick.

Voltage lag is serious,  as a demonstration, watch your voltage, or have someone else stare at the display as you power up and take off.  The voltage will dip significantly.  Land and disarm, the voltage comes back up by the amount of lag.

Current never stops changing, so the voltage is responding

I had a similar problem like that.  It looked fine on the bench but when I went to fly it dipped a lot and caused it to fail safe and land.  I later determined that it was caused by a damaged power module.  The module providing power was not damaged but the electronics that was detecting the voltage was bad.

I ended up replacing the power module and all was well again.  I think what happened was that one of the pins shorted to the current pin and damaged the output reading.  After fixing this issue the voltage reading were never right.

So it could be just a bad voltage monitor.

Well a bad power module is better than voltage lag creating your problem.

Have you measured your current during a flight from an independent source?

Why are you using 70A esc's when you hover at 10A?

I havent. And i dont think i have mentioned what ESC im using :) Im using 20A esc. I guess i will just order new power module and wait for it.

Harry Courter said:

Well a bad power module is better than voltage lag creating your problem.

Have you measured your current during a flight from an independent source?

Why are you using 70A esc's when you hover at 10A?

Reply to Discussion

RSS

© 2017   Created by Chris Anderson.   Powered by

Badges  |  Report an Issue  |  Terms of Service