[Waddiewadkins]

I am not from QUDELIX, but if you agree, I can explain something.

The charger is inside the device, always.
What we call 'USB chargers', in reality it would be more correct to call them USB power supplies.

If they are compatible with the PD or QC standards, they are able to supply a voltage greater than the standard 5V. But this supply of greater voltage occurs exclusively upon request of the device being charged, after specific negotiation.
In the case of the 5K, it does not occur, and therefore any USB power supply supplies the standard 5V.

Regarding the 80% charge limit, it actually has value and protects the internal cell, especially if it is left for many hours in a fully charged state.

In other words, the cell left charged at 100% rather than 80%, undergoes greater degradation.

But these are known recommendations, which are valid for practically every device equipped with lithium cells.

Less subject to this type of ‘degradation’ are lithium iron phosphate (LiFePO4) cells, but they are rarely used as single cells in electronic devices, for various reasons, one of which is their lower nominal voltage (3.3V instead of 3.7-3.8V).

So the 80% limit is to protect against a Qudelix if left in plugged in charging, unattended? Or is the 80% going to protect it in all scenarios... I mean if I charge to 100% and I am unplugging it straight away, or 10 mins later, it's actually OK on the battery?

 

[Hypops]

Just out of curiosity, does Quedix drain battery of the phone or the Quedix when in usb mode to the phone?

God I miss the headphone jack on the our phones. Life was so much more convenient.

There's an adjustable setting to choose how/when you want the Q5K to be charged. As for phones, yes. But there are also DAPs which are every bit as convenient as phones used to be when they had built in DACs, amps, and 3.5mm connections.

I am not from QUDELIX, but if you agree, I can explain something.

The charger is inside the device, always.
What we call 'USB chargers', in reality it would be more correct to call them USB power supplies.

If they are compatible with the PD or QC standards, they are able to supply a voltage greater than the standard 5V. But this supply of greater voltage occurs exclusively upon request of the device being charged, after specific negotiation.
In the case of the 5K, it does not occur, and therefore any USB power supply supplies the standard 5V.

Regarding the 80% charge limit, it actually has value and protects the internal cell, especially if it is left for many hours in a fully charged state.

In other words, the cell left charged at 100% rather than 80%, undergoes greater degradation.

But these are known recommendations, which are valid for practically every device equipped with lithium cells.

Less subject to this type of ‘degradation’ are lithium iron phosphate (LiFePO4) cells, but they are rarely used as single cells in electronic devices, for various reasons, one of which is their lower nominal voltage (3.3V instead of 3.7-3.8V).

Huh. I assume this is the reason so many USB charged devices only come with a cable, but not an actual wall wart transformer?

 

[SilverEars]

I am not from QUDELIX, but if you agree, I can explain something.

The charger is inside the device, always.
What we call 'USB chargers', in reality it would be more correct to call them USB power supplies.

If they are compatible with the PD or QC standards, they are able to supply a voltage greater than the standard 5V. But this supply of greater voltage occurs exclusively upon request of the device being charged, after specific negotiation.
In the case of the 5K, it does not occur, and therefore any USB power supply supplies the standard 5V.

Regarding the 80% charge limit, it actually has value and protects the internal cell, especially if it is left for many hours in a fully charged state.

In other words, the cell left charged at 100% rather than 80%, undergoes greater degradation.

But these are known recommendations, which are valid for practically every device equipped with lithium cells.

Less subject to this type of ‘degradation’ are lithium iron phosphate (LiFePO4) cells, but they are rarely used as single cells in electronic devices, for various reasons, one of which is their lower nominal voltage (3.3V instead of 3.7-3.8V).

You sir explain it a lot better than I can. I thought the reason for limiting the charge to 80% is due to heat released when charging to higher capacity, which degrades the battery. High heat is bad for battery life. I see people bringing in wireless earphone, or cell phones to the sauna all the time and shake my head.

There's an adjustable setting to choose how/when you want the Q5K to be charged. As for phones, yes. But there are also DAPs which are every bit as convenient as phones used to be when they had built in DACs, amps, and 3.5mm connections.


Huh. I assume this is the reason so many USB charged devices only come with a cable, but not an actual wall wart transformer?

I have to use phones for calls, but phones these days do not have a headphone jack, that's the big inconvenience for me. Having to charge another device, etc.. I don't like to use TWS because the mic sucks on them. I prefer inline mic, which is the reason why I'm going for bt device instead.

 

[Ferdinando1968]

So the 80% limit is to protect against a Qudelix if left in plugged in charging, unattended? Or is the 80% going to protect it in all scenarios... I mean if I charge to 100% and I am unplugging it straight away, or 10 mins later, it's actually OK on the battery?

The 80% limit forces the QUDELIX internal charger to deactivate the cell charge as soon as it reaches 80% of its maximum charge voltage (which in the case of the 5K is about 4.30-4.35V).

This voltage limit is never exceeded even if the device remains connected to the USB power supply.

Personally, if I know that I will have to leave the device unused for a long period (>2 weeks), I try to leave the battery charged at a percentage lower than 80% (say 50-60%), because a lower percentage is even more cautious than 80%.

80% was probably chosen as a compromise value between a certain degree of protection of the internal battery and a sufficient energy reserve to allow a reasonable autonomy of use of the device.

If I know for sure that I will use the device immediately after charging, I charge it to 100%, because I know that the cell will not remain in that state for a long time, as it will be discharged by the imminent use.

In essence ‘degradation’ occurs due to the maximum charge maintained for a prolonged time.
(time plays an important role in this context)

Huh. I assume this is the reason so many USB charged devices only come with a cable, but not an actual wall wart transformer?

I think that choice is more dictated by the need to avoid unnecessary environmental pollution, caused by the construction of useless equipment, because it is assumed that everyone already has a USB power supply that meets their needs.
It is a questionable thought obviously, because the assumption is not necessarily true.

Another reason is obviously of an economic nature, because it saves those who sell the cost of the power supply

 

[Waddiewadkins]

The 80% limit forces the QUDELIX internal charger to deactivate the cell charge as soon as it reaches 80% of its maximum charge voltage (which in the case of the 5K is about 4.30-4.35V).

This voltage limit is never exceeded even if the device remains connected to the USB power supply.

Personally, if I know that I will have to leave the device unused for a long period (>2 weeks), I try to leave the battery charged at a percentage lower than 80% (say 50-60%), because a lower percentage is even more cautious than 80%.

80% was probably chosen as a compromise value between a certain degree of protection of the internal battery and a sufficient energy reserve to allow a reasonable autonomy of use of the device.

If I know for sure that I will use the device immediately after charging, I charge it to 100%, because I know that the cell will not remain in that state for a long time, as it will be discharged by the imminent use.

In essence ‘degradation’ occurs due to the maximum charge maintained for a prolonged time.
(time plays an important role in this context)


I think that choice is more dictated by the need to avoid unnecessary environmental pollution, caused by the construction of useless equipment, because it is assumed that everyone already has a USB power supply that meets their needs.
It is a questionable thought obviously, because the assumption is not necessarily true.

Another reason is obviously of an economic nature, because it saves those who sell the cost of the power supply

Wow , so even if plugged out, just having the charge held in the battery without being discharged for a prolonged period is degrading.. Thanks for info, my mind at ease, will continue to use freely daily 100% charge and use without worry.

 

[Eric0]

Thanks for info, my mind at ease, will continue to use freely daily 100% charge and use without worry.

When the Q5k reaches the desired charge, it turns off charging.

I don't usually leave mine charging overnight. Occasionally, I'll forget. Last night was an example.

I have it set to stop at 80%. But that really means about 70%. It was left on and plugged in. It stopped at a 70% charge and then because it was on, it slowly used power for 10 hours or so. It was at 60% when I wanted to use it this morning.

This is a good thing. It means it isn't constantly charging as it uses power. It charges, and then stops. Many phones will just keep charging as long as they are plugged in.

 

[kalibri]

God I miss the headphone jack on the our phones. Life was so much more convenient.

The good news is that there are still phones with jacks, like my Asus Zenfone 10 (the output is really good quality) and some Sony Xperia models. But not many unfortunately.

 

[Waddiewadkins]

When the Q5k reaches the desired charge, it turns off charging.

I don't usually leave mine charging overnight. Occasionally, I'll forget. Last night was an example.

I have it set to stop at 80%. But that really means about 70%. It was left on and plugged in. It stopped at a 70% charge and then because it was on, it slowly used power for 10 hours or so. It was at 60% when I wanted to use it this morning.

This is a good thing. It means it isn't constantly charging as it uses power. It charges, and then stops. Many phones will just keep charging as long as they are plugged in.

Right son just in general setting it to 80% is just healthier for battery across the board?

 

[Eric0]

Right son just in general setting it to 80% is just healthier for battery across the board?

That's my understanding. The engineers have arbitrarily created 109% at a level they believe balances useful time before needing to charge and the overall battery health. 100% isn't the max which the battery will theoretically hold. It's the max which the engineers set.

It's just that charging slightly below that should extend the overall lifetime of the battery. If that gives you sufficient charge for each use, might as well use 80% because it's not hurting anything and is potentially helping.

 

[Waddiewadkins]

That's my understanding. The engineers have arbitrarily created 109% at a level they believe balances useful time before needing to charge and the overall battery health. 100% isn't the max which the battery will theoretically hold. It's the max which the engineers set.

It's just that charging slightly below that should extend the overall lifetime of the battery. If that gives you sufficient charge for each use, might as well use 80% because it's not hurting anything and is potentially helping.

And the red light goes off quicker too!

 

[kalibri]

The engineers have arbitrarily created 109% at a level they believe balances useful time before needing to charge and the overall battery health.

Nah, the 5k is a very simple device and doesn't have such logic.

The numbers you're seeing in the app are NOT accurate because they represent voltage, the 5K seems to have a very poor/cheap/simple BMS (battery management system) which doesn't measure the actual battery capacity but estimates based on voltage, which is not precise at all (because voltage drops under load).

E.g. during charging, higher voltage at the source is how charge is "pushed" into the battery and the number showed is either the source voltage (likely) or the battery voltage (unlikely because LiPo batteries have distinct CV (constant voltage)/CC (constant current) phases which are followed by every BMS out there. So you see voltages higher than the max voltage of the battery, hence capacities which can seem higher than the battery can hold, because the 5k BMS is a very very basic one.

So my advice would be to just use it, ignore the numbers and if you want long battery health enable the 80% limit (which is more like 70% due to how the voltage is measured when the source is connected so higher than the actual battery voltage).

 

[Ferdinando1968]

Nah, the 5k is a very simple device and doesn't have such logic.

The numbers you're seeing in the app are NOT accurate because they represent voltage, the 5K seems to have a very poor/cheap/simple BMS (battery management system) which doesn't measure the actual battery capacity but estimates based on voltage, which is not precise at all (because voltage drops under load).

E.g. during charging, higher voltage at the source is how charge is "pushed" into the battery and the number showed is either the source voltage (likely) or the battery voltage (unlikely because LiPo batteries have distinct CV (constant voltage)/CC (constant current) phases which are followed by every BMS out there. So you see voltages higher than the max voltage of the battery, hence capacities which can seem higher than the battery can hold, because the 5k BMS is a very very basic one.

So my advice would be to just use it, ignore the numbers and if you want long battery health enable the 80% limit (which is more like 70% due to how the voltage is measured when the source is connected so higher than the actual battery voltage).

The reasons why the cell voltage, shown during charging, is higher than the voltage shown when charging is complete, are (as a first approximation) 2:

1. the cell has an internal resistance (which increases as the cell is ‘worn’), a resistance on which a voltage falls given by the product of the charging current by the internal resistance (V=RxI)
This voltage drop is added to the actual voltage of the cell

https://en.wikipedia.org/wiki/Internal_resistance

https://data.energizer.com/pdfs/batteryir.pdf

2. the voltage measurement is NOT performed with the
4-wire method (so-called Kelvin measurement)

https://en.wikipedia.org/wiki/Four-terminal_sensing

so when it is charging, there is a voltage drop on the wires that is not compensated, and is added to the cell voltage


There are also other phenomena that produce a
a ‘relaxation’ of the voltage delivered by the cell following a certain rest period after charging (which has nothing to do with the phenomenon of self-discharge, the effect of which is eventually added).

And yes, it is true, the cell voltage is not a reliable indicator of what in jargon is called SoC (state of charge), to measure which it would be necessary to measure the charge (Coulomb) actually introduced into the cell; however, it is a widely used method, which if moderated by appropriate software algorithms, is sufficiently reliable for common purposes.

 

[Rienm]

Qudelix and FiiO LT-LT2, does not work..
I’am listening my hires music from my iPhone-> Qudelix via lightning-> USB c , using the Apple camera connection kit. It is a bit clumsy, so I did search for an other solution. Read that I have to buy an OTG cable, so I bought the FiiO Lt-Lt 2. But……..it does not work at all. Charging is “Off”
I don’t understand it. Faulty cable????

The next day I found out that the problem is not the cable, but the connection to the lightning port. Or the port on my iPhone 12 Pro or the lightning connector from the Lt-Lt2… on the other hand, the connection from Apple’s camera connection kit is too not stable, small movements will cause a disconnection… perhaps cleaning the lightning port with alcohol will help…

 

[Alex34]

So, I've "upgraded" my phone from Samsung Galaxy Note 9 to the Galaxy S24 Ultra.

As soon as I plugged my 5K into the S24 Ultra and started playing music, I was immediately disappointed. Music sounds harsh and bright on the S24 Ultra, and nowhere near as good as it did on my Note 9. I was a bit surprised by this, as I thought USB DACs would have more control over the end result than the phone would.

I've spent hours checking and changing settings on the S24 Ultra but nothing helps. Before I send this phone back, is there anyone that can possibly help? Maybe I am overlooking something? I thought the sound quality produced by the 5K would be the same no matter the phone?

 

[Waddiewadkins]

So, I've "upgraded" my phone from Samsung Galaxy Note 9 to the Galaxy S24 Ultra.

As soon as I plugged my 5K into the S24 Ultra and started playing music, I was immediately disappointed. Music sounds harsh and bright on the S24 Ultra, and nowhere near as good as it did on my Note 9. I was a bit surprised by this, as I thought USB DACs would have more control over the end result than the phone would.

I've spent hours checking and changing settings on the S24 Ultra but nothing helps. Before I send this phone back, is there anyone that can possibly help? Maybe I am overlooking something? I thought the sound quality produced by the 5K would be the same no matter the phone?

So, I've "upgraded" my phone from Samsung Galaxy Note 9 to the Galaxy S24 Ultra.

As soon as I plugged my 5K into the S24 Ultra and started playing music, I was immediately disappointed. Music sounds harsh and bright on the S24 Ultra, and nowhere near as good as it did on my Note 9. I was a bit surprised by this, as I thought USB DACs would have more control over the end result than the phone would.

I've spent hours checking and changing settings on the S24 Ultra but nothing helps. Before I send this phone back, is there anyone that can possibly help? Maybe I am overlooking something? I thought the sound quality produced by the 5K would be the same no matter the phone?

Gpt says:

Gpt says..
You're correct that, in theory, the phone itself shouldn't affect the sound quality of the Qudelix 5K when it's operating in USB DAC mode. In this mode, the phone acts purely as a digital source, sending data to the Qudelix, which handles the digital-to-analog conversion and amplification. However, there are a few factors that could explain the perceived change in sound:

1. Audio Source Quality:
The new phone might use a different music player app, settings, or audio codecs, which could influence the quality of the digital signal being sent to the Qudelix.


2. USB Signal Integrity:
If the new phone has issues with USB signal stability or uses a lower-quality cable, it could lead to jitter or errors in the digital signal, potentially impacting audio quality.


3. Output Settings:
The new phone might have different USB audio settings (e.g., sample rate, bit depth, or default volume), which might influence the sound or require manual adjustment in the Qudelix app.


4. Psychological Bias:
If the user expects a difference in sound quality due to the new phone, this might lead to a perceived change, even if none exists objectively.


5. Firmware or App Differences:
The Qudelix app on the new phone might have different settings or firmware that hasn't been updated, potentially altering the sound.



Suggestions:

Ensure the Qudelix firmware is up to date.

Check USB audio settings on the new phone.

Compare the sound with another device to rule out subjective bias.

Test with a different USB cable to eliminate potential signal issues.


If none of these solve the issue, it might be worth exploring whether the new phone has quirks in its USB output, although this would be uncommon.