Battery Protection Circuit on 2700mAh 7.4v Hubsan Batteries. Please Explain

[justjarhead]

There seems to be a concern on Facebook in the Hubsan H501 / H502/ H122 forum regarding the Overload protection circuit that has been added to the battery some time in the last 18 months.

The concern is that the Overload Protection circuit is tripping unexpectedly while flying an unmodified H501 series Quad. This brick effect can be deadly to an H501 quad when flying over water or at any high altitude. If the Overload Protection trips while in flight the Quad shuts down and will fall to the earth like a brick without ability to recover. Lose a H501 or have LIPO fire.

I believe the Overload Protection circuit is to deal with conditions that can result in a LIPO fire or explosion. Is this correct?

Why did Hubsan add the Overload Protection Circuit to its battery design?

What are the typical conditions that trip and crowbar the Overload Protection Circuit?
How do you avoid these conditions?
When was Overload Protection Added to the Battery Design?

There seems to be a misconception that this happens only when battery is low. It has happened to me twice with battery at 70% or higher while aggressively flying in GPS mode with full throttle high yaw and high forward turn movement ( left stick full top left and right stick full top left) Thank god I was at around 10 meters or less in altitude and not over water.

In the last day or so after Tom Dudley posted a youtube video about the circuit people on both sides of the fence became pretty vocal.

I hope Hubsan can enlighten us and make recommendations re: interaction with this issue!

[SomeGuy]

Personally I think this is a bunch of BS by those that want to sell batteries. If this were a legitimate problem H501S quads would be dropping out of the sky like rain. For a couple days now I have been searching the net on blogs and forums for this type of incident during the last 6 months and have not found a single report of a 501S just dropping from the sky. Not saying it can't happen because if you lose a motor and possibly other catastrophic failures the quad is going to go down. Besides, how aggressively can one fly the 501S in GPS Mode? Unless you are deliberately trying to crash the FC firmware. Now, flying aggressively with GPS off or in full manual, now that is something else entirely.

You say this has happened to you twice. If this is the case then it can be repeated so do the entire Hubsan community a big favor and repeat it while recording video on your phone and post to YouTube.

[justjarhead]

Personally I think this is a bunch of BS by those that want to sell batteries. If this were a legitimate problem H501S quads would be dropping out of the sky like rain. For a couple days now I have been searching the net on blogs and forums for this type of incident during the last 6 months and have not found a single report of a 501S just dropping from the sky. Not saying it can't happen because if you lose a motor and possibly other catastrophic failures the quad is going to go down. Besides, how aggressively can one fly the 501S in GPS Mode? Unless you are deliberately trying to crash the FC firmware. Now, flying aggressively with GPS off or in full manual, now that is something else entirely.

You say this has happened to you twice. If this is the case then it can be repeated so do the entire Hubsan community a big favor and repeat it while recording video on your phone and post to YouTube.

If your going to quote me, quote me correctly. I never said I could repeat it I said it happened to me twice. Personally I wouldn't attempt to purposely brick my H501A in the first months of ownership.

As far as H501 series drones falling out of the sky I have the same feeling with my 2 exceptions that have not happened since. At the time they occured all I saw was LEDS go out and my H501A fall from the sky.

I asked for an explanation of the Overload Protection circuits so I don't cause an Overload. I personally would rather have them there vs LIPO fire or explosion.

SomeGuy cool your jets.

[SomeGuy]

If your going to quote me, quote me correctly. I never said I could repeat it I said it happened to me twice. Personally I wouldn't attempt to purposely brick my H501A in the first months of ownership.

As far as H501 series drones falling out of the sky I have the same feeling with my 2 exceptions that have not happened since. At the time they occured all I saw was LEDS go out and my H501A fall from the sky.

I asked for an explanation of the Overload Protection circuits so I don't cause an Overload. I personally would rather have them there vs LIPO fire or explosion.

SomeGuy cool your jets.

I did not mean to infer that you could repeat the event. You were very specific as to what you were doing with the controls when the event occurred so that would indicate that the event could likely be repeated. I have flown my 501SS very aggressively with GPS off and believe me they are much faster and more responsive and I had no problems and that was before I even knew about any protective battery circuits. My quad is black and it was 97 deg. bright sun, middle of the day. The battery was so hot when done I could hardly hold it but no power problems. Protective circuits are very common in li-po batteries. If you Google "lipo protection circuit" you should find the answers to any questions you may have. I do know that the Hubsan battery will cut off if either cell drops below 3 volts in order to prevent over discharge of the battery so my best practice is to keep an eye on the voltage and always land before the voltage drops to 6.7 volts. If your quad is still in the air when you get the Aircraft Low Battery warning I would land ASAP and hopefully the quad is not too far from the Home Point. From my observations, you don't have a lot of time from the Low Battery warning to the quad getting less responsive. Hubsan advertises 20 min flight time but I think 18 min is more realistic. I prefer using a battery that is equipped with this circuitry as many battery experts say you are pushing the envelope of battery safety by using batteries without it. Even the DJI Phantoms use protection circuits in their batteries although far more sophisticated.

Happy Flying

[SomeGuy]

There seems to be a misconception that this happens only when battery is low. It has happened to me twice with battery at 70% or higher while aggressively flying in GPS mode with full throttle high yaw and high forward turn movement ( left stick full top left and right stick full top left) Thank god I was at around 10 meters or less in altitude and not over water.

I hope Hubsan can enlighten us and make recommendations re: interaction with this issue!

Hey, Still interested in your drone episode because I want to have confidence in the drone if I am going to fly long range a lot and from my observations and lots of reading I don't think there should be any concern using the Hubsan battery in the 501S. Anyway, something just hit me. The most voltage you should have from the Hubsan battery if not overcharged is 8.4V. If you were at 70% or possibly higher you could have been close to the low voltage cutoff. 70% of 8.4 = 5.88. 75% of 8.4 = 6.3. Depending on the accuracy of the controller volt readout, it's possible you hit the low voltage threshold.

The very least Hubsan should do is post the Battery Data Sheet. I would imagine there is a requirement to provide one if requested.

[justjarhead]

Thank you for the response. I do have a base understanding of Protection circuits but wanted some specifics from Hubsan on theirs.

I actually agree that they should be implemented I just wanted some more info so I don't brick.

The search term you suggested is a great idea. Thanks.

Happy Hubsan Flying

[justjarhead]

There seems to be a misconception that this happens only when battery is low. It has happened to me twice with battery at 70% or higher while aggressively flying in GPS mode with full throttle high yaw and high forward turn movement ( left stick full top left and right stick full top left) Thank god I was at around 10 meters or less in altitude and not over water.

I hope Hubsan can enlighten us and make recommendations re: interaction with this issue!

Hey, Still interested in your drone episode because I want to have confidence in the drone if I am going to fly long range a lot and from my observations and lots of reading I don't think there should be any concern using the Hubsan battery in the 501S. Anyway, something just hit me. The most voltage you should have from the Hubsan battery if not overcharged is 8.4V. If you were at 70% or possibly higher you could have been close to the low voltage cutoff. 70% of 8.4 = 5.88. 75% of 8.4 = 6.3. Depending on the accuracy of the controller volt readout, it's possible you hit the low voltage threshold.

The very least Hubsan should do is post the Battery Data Sheet. I would imagine there is a requirement to provide one if requested.

The percentage I am referring to is the percentage of useable battery as displayed by the Hubsan APP. It does not display voltage but percentage of useable battery left. When at 20% useable battery you had better have landed. 10% useable battery is in the neighborhood of 6.8v. The HT011A and the APP behave differently than the H901A or H906A.

Good luck getting Hubsan to provide battery data.

[gjvo]

In short...
Bullshit.
I have a battery 2700 mAh 2S from the Hubsan H507M and there is nothing inside.
No protectioncircuit at all.
There is only the 2 wires to the EC3 connector and a balance (charge) connector.
That is soldered direct on the solderlips.
I can make a picture of it but i cannot post it here.

I made a lot of lipo packs for my modelplanes so i know what i am talking about.

Sometimes a lipo battery just stops working, if 1 cell stops than you loose everything, maybe that causes the problem.
And another thing:
A lipo fully charged is 4,2 Volts per cel, if you start the motors the voltage drops in seconds to 3.9 per cell or if you draw more current it drops to 3.7 volts per cel.
So if you see 100% in your display the voltage is about 8 Volts, you better stop flying if it get less than 40%.
Than the voltage per cel is under 3.2 Volt per cel, lower than that damages your cells.
You can get a bit more flying time if you heat the lipo for an hour at 38 degree Celcius.

In my modelplanes i drew currents of 400-450 Amps, if you dont heat up your cells than they dont work anymore, you can throw them away.

Gert-Jan

[justjarhead]

In short...
Bullshit.
I have a battery 2700 mAh 2S from the Hubsan H507M and there is nothing inside.
No protectioncircuit at all.
There is only the 2 wires to the EC3 connector and a balance (charge) connector.
That is soldered direct on the solderlips.
I can make a picture of it but i cannot post it here.

I made a lot of lipo packs for my modelplanes so i know what i am talking about.

Sometimes a lipo battery just stops working, if 1 cell stops than you loose everything, maybe that causes the problem.

Gert-Jan

There are two versions of the 2700mAh 7.4v 10C battery.

One with Overload Protection and One without.

Most new Hubsan batteries have the protection circuit and that is why the question was asked. All that is being asked for are the specifications and guidelines & limitation of the Overload Protected Battery.

Sorry to rain on your parade.

[gjvo]

So than i have an old battery?
I received the H507M 2 weeks ago.

I looked at some pictures in RCgroups.
It is not a protection circuit, it is for charging.
Some chargers are not real lipo chargers, they just deliver a voltage (about 5 Volt and a current.
The circuit balances the cells and protect them for overvoltage during charging.

In the normal world it is called a battery control circuit.


GJ