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NEW: iPower AA batteries. Li-poly rechargeable.


Derek H
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1 hour ago, MartinTheMixer said:

Hi Johnny, are you saying that somehow, the 2 batteries were wired in series, and somehow the unit managed to not use the one cell, that was in series? Hey SMQV people weigh in here, are the 2 cells in parallel? And not series? 

Thank you. 

I believe they are in parallel. Otherwise it would double the voltage, right? And since you can run an SMQV with a single battery....

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47 minutes ago, Johnny Karlsson said:

I believe they are in parallel. Otherwise it would double the voltage, right? And since you can run an SMQV with a single battery....

This would be easy to identify, try checking if it will run with a cell in either of the 2 positions, 1 cell at a time, if it does run, then yes, it is in parallel, which I have a hard time believing. 

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11 minutes ago, MartinTheMixer said:

This would be easy to identify, try checking if it will run with a cell in either of the 2 positions, 1 cell at a time, if it does run, then yes, it is in parallel, which I have a hard time believing. 

Like I said, it does. See the above tests. It’s a well known fact. Not sure why you would have a hard time believing that. 

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19 minutes ago, LarryF said:

Parallel.

Larry (Odd Designer) Fisher

Larry, haha,  I looked it up, I see the battery eliminater, now I see what you were doing. What is your theory on what happened in the referenced case? Only one battery reported to have been utilized. I still stand by my position that this scheme is different than what is usual or expected. Is there any other transmitter manufacturer that uses this scheme? Thank you, Martin

 

 

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59 minutes ago, MartinTheMixer said:

Larry, haha,  I looked it up, I see the battery eliminater, now I see what you were doing. What is your theory on what happened in the referenced case? Only one battery reported to have been utilized. I still stand by my position that this scheme is different than what is usual or expected. Is there any other transmitter manufacturer that uses this scheme? Thank you, Martin

 

 

The li-ion rechargeable battery has to have a sensing circuit to turn it on when there is a load, otherwise it would stay on all the time and run down in a day or so from the voltage converter residual drain. My guess is that in the two battery setup in the SMQV, the higher voltage li-ion battery is turned "on" while the other battery sees more than its full voltage at its output and thinks it is looking at an open circuit, i.e., not in a device. It stays off. At some point the first battery begins to die and the second battery sees less voltage than open circuit and tries to turn on. If it starts to power the SMQV, then the first battery sees less of a load on its internal cell and it tries to turn back on. My guess is that the SMQV doesn't know what to do with rising and falling voltages and shuts down. Having three switching power supplies all sensing the input voltage (two outputing in the two batteries and one inputing in the SMQV) , I'd be very suprised if the various units didn't go into oscillation. It would require a scope hooked up to the units to decipher the problem.
By the way, the Lectro transmitters will operate at full power down to 0.9 Volts, so as to get every bit of power out of an AA battery.
Best Regards,

Larry Fisher

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2 hours ago, LarryF said:

The li-ion rechargeable battery has to have a sensing circuit to turn it on when there is a load, otherwise it would stay on all the time and run down in a day or so from the voltage converter residual drain. My guess is that in the two battery setup in the SMQV, the higher voltage li-ion battery is turned "on" while the other battery sees more than its full voltage at its output and thinks it is looking at an open circuit, i.e., not in a device. It stays off. At some point the first battery begins to die and the second battery sees less voltage than open circuit and tries to turn on. If it starts to power the SMQV, then the first battery sees less of a load on its internal cell and it tries to turn back on. My guess is that the SMQV doesn't know what to do with rising and falling voltages and shuts down. Having three switching power supplies all sensing the input voltage (two outputing in the two batteries and one inputing in the SMQV) , I'd be very suprised if the various units didn't go into oscillation. It would require a scope hooked up to the units to decipher the problem.
By the way, the Lectro transmitters will operate at full power down to 0.9 Volts, so as to get every bit of power out of an AA battery.
Best Regards,

Larry Fisher

Larry, Good stuff to know, thanks for the answer. 

.9 volts, wow, what is the amperage at that point? 

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Thank you so much Johnny for the tests! And Larry for the explanations and very plausible theory.

 

I also guess that the self protection of the power management board of the battery, as with any Lithium rechargeable batteries, would shut down earlier to prevent under voltage state of the cell(s).

 

Johnny did you get to see what is the battery telemetry status of the tx before shutting down?

 

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3 hours ago, Fred Salles said:

Thank you so much Johnny for the tests! And Larry for the explanations and very plausible theory.

 

I also guess that the self protection of the power management board of the battery, as with any Lithium rechargeable batteries, would shut down earlier to prevent under voltage state of the cell(s).

 

Johnny did you get to see what is the battery telemetry status of the tx before shutting down?

 

I trust Larry's theory. 

Based on that and what I see in my tests, I will conclude that these particular rechargeable Litihum AA batteries might be ok to use in single battery units, but not exactly ideal in dual battery units.

 

4:40 in a single battery unit at 50mw is usable for some applications. One advantage over NIMH is that these are lighter weight.

 

Just for the heck of it, I will run a fresh eneloop Pro at 50 mw in a SMV tonight to compare the run time.

 

Fred - I did not watch the receiver while running the test. I just set the SRC to AAT (timer), which stops when the transmitter shuts off. So, no I did not see the telemetry.

 

2 hours ago, drpro said:

And this is why Lectrosonics continues to get my vote.  They share technical details willingly.  Plus Larry gets the big bucks!!

Yup. +1

 

 

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9 hours ago, Johnny Karlsson said:

4:34 with the fresh eneloop pro at 50mw, so pretty much same.

In theory you should be able to do better with Eneloop pro. 

13 hours ago, Johnny Karlsson said:

One advantage over NIMH is that these are lighter weight.

 

 

 


The main advantage of NIMH is the predictability of run time based on the drain. 
the main reason “ apart from cost” I try to use NIMH on everything. 
I have zero interest in the current lithium rechargeable technologies. 
Sometimes there is no need to reinvent the wheel. 

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4 hours ago, RadoStefanov said:

In theory you should be able to do better with Eneloop pro. 


The main advantage of NIMH is the predictability of run time based on the drain. 
the main reason “ apart from cost” I try to use NIMH on everything. 
I have zero interest in the current lithium rechargeable technologies. 
Sometimes there is no need to reinvent the wheel. 

In theory, yes - but depends on which theory. Since the current draw is higher at 1.2V that it is at 1.5V. That’s what got me curious and made me want to test these to see what it meant in practice. And that does seem to even things out in terms of runtime.

 

But no, I’m not planning to switch over to these.

 

Now, if anyone could make a safe AA rechargeable that could run a DBSM for 6h30min, THAT would make me switch! (Not expecting that happening any time

soon).

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Thank you again Johnny for buying and doing a full run of conclusive tests !!

 

My friend said he run his wisycom MTP41 for longer time with one of these ELL than with the eneloop pro, BUT he has not done real test like yours, so it just a feeling really. And since he changes them at lunch time before they could shut down, there is no point in comparing the run time for him.  But the weight difference is what makes him choose the lithium over the nimh ones. He actually bought them first for a shoot in Siberia at minus 30° Celsius average temperature, as they are suppose to handle cold better than nimh. Then he sticks to some of it for the weight advantage. Also the small USB charger over the bigger nimh dedicated charger is a plus if you can carry only one bag.

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41 minutes ago, Johnny Karlsson said:

In theory, yes - but depends on which theory. Since the current draw is higher at 1.2V that it is at 1.5V. That’s what got me curious and made me want to test these to see what it meant in practice. And that does seem to even things out in terms of runtime.

 

But no, I’m not planning to switch over to these.

 

Now, if anyone could make a safe AA rechargeable that could run a DBSM for 6h30min, THAT would make me switch! (Not expecting that happening any time

soon).

At the same draw mAh power is mAh power. It should be… “ to be clear” IT IS less than eneloop pro 2550-2600 mAh

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29 minutes ago, RadoStefanov said:

At the same draw mAh power is mAh power. It should be… “ to be clear” IT IS less than eneloop pro 2550-2600 mAh

I do not follow you. 1.2v*2.55A=3.06Wh for the Eneloop, the EBL are rated 3.3Wh, so on paper the EBL should run longer (slightly) with 240mWh extra capacity.

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35 minutes ago, RadoStefanov said:

At the same draw mAh power is mAh power. It should be… “ to be clear” IT IS less than eneloop pro 2550-2600 mAh

Right, but...

The theory I wanted explore was that the transmitter draws more current when the voltage is lower, and therefore would potentially drain the battery quicker.

 

This Lithium AA:

 

3300mWh @ 1.5V = 2200mAh

 

And NiMh:

 

2450mAh @ 1.2V = 2940mWh

 

2550mAh  @ 1.2V = 3060mWh

 

2700mAh @ 1.2V = 3240mWh

 

Of course, one thing that throws the formula off is, the NiMh doesn’t start at 1.2V fresh off the charger. It can be as high as 1.47V, then drops down to around 1.35V over the first 15 min or so. Then gradually drops further. So using the above calculation formulas does not give you the accurate comparison. That’s why running the tests in real life seemed to make more sense. And again the tests I did shows that the practical run-time is about equal.

 

 

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4 minutes ago, Johnny Karlsson said:

Right, but...

The theory I wanted explore was that the transmitter draws more current when the voltage is lower, and therefore would potentially drain the battery quicker.

 

This Lithium AA:

 

3300mWh @ 1.5V = 2200mAh

 

And NiMh:

 

2450mAh @ 1.2V = 2940mWh

 

2550mAh  @ 1.2V = 3060mWh

 

2700mAh @ 1.2V = 3240mWh

 

Of course, one thing that throws the formula off is, the NiMh doesn’t start at 1.2V fresh off the charger. It can be as high as 1.47V, then drops down to around 1.35V over the first 15 min or so. Then gradually drops further. So using the above calculation formulas does not give you the accurate comparison. That’s why running the tests in real life seemed to make more sense. And again the tests I did shows that the practical run-time is about equal.

 

 

A couple of things to consider. I don’t think any of us are running Energizer lithiums until their dead, so, users vary, but maybe 20 percent of the capacity of an energizer lithium is unusable. On the micro USB rechargeable, you can change as often as you like and you're never "throwing away" capacity like we do with the Energizer lithiums. And, the current doesn't go up on the rechargeable lithiums because they start at about 1.5 volts and once fully discharged, they are still about 1.5 volts.  Thank you. 

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10 hours ago, Johnny Karlsson said:

Right, but...

The theory I wanted explore was that the transmitter draws more current when the voltage is lower, and therefore would potentially drain the battery quicker.

 

This Lithium AA:

 

3300mWh @ 1.5V = 2200mAh

 

And NiMh:

 

2450mAh @ 1.2V = 2940mWh

 

2550mAh  @ 1.2V = 3060mWh

 

2700mAh @ 1.2V = 3240mWh

 

Of course, one thing that throws the formula off is, the NiMh doesn’t start at 1.2V fresh off the charger. It can be as high as 1.47V, then drops down to around 1.35V over the first 15 min or so. Then gradually drops further. So using the above calculation formulas does not give you the accurate comparison. That’s why running the tests in real life seemed to make more sense. And again the tests I did shows that the practical run-time is about equal.

 

 


I had no idea mah means something else but milliampere hour. 
sorry. Don’t mean to be an asshole.  
But I think since the great senator  Mike Michaels is not participating anymore I will try to put his weight and his tradition on my shoulders. 
🙂

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3 hours ago, RadoStefanov said:


I had no idea mah means something else but milliampere hour. 
sorry. Don’t mean to be an asshole.  
But I think since the great senator  Mike Michaels is not participating anymore I will try to put his weight and his tradition on my shoulders. 
🙂

Haha, well good luck with that.

 

A milliamp hour is a milliamp hour, yes, but in a device that draws 500 milliamps vs one that draws 900 milliamps will make a difference in how long the battery will last.

 

In this case, we are comparing apples and oranges, because one of the batteries puts out a constant voltage until it dies, the other one gradually drops the voltage.

 

What I thought might make a difference is the fact that the particular device I was testing the batteries with draws more current when it sees a lower voltage.

That’s why I wanted to run the test to see what the actual real difference in runtime (if any) would be.

 

I am not an electrician so it’s completely possible I’m confused, but anyway, I feel that I found out what I wanted to find out, and shared it here for those who care.

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5 hours ago, Johnny Karlsson said:

Haha, well good luck with that.

 

A milliamp hour is a milliamp hour, yes, but in a device that draws 500 milliamps vs one that draws 900 milliamps will make a difference in how long the battery will last.

 

In this case, we are comparing apples and oranges, because one of the batteries puts out a constant voltage until it dies, the other one gradually drops the voltage.

 

What I thought might make a difference is the fact that the particular device I was testing the batteries with draws more current when it sees a lower voltage.

That’s why I wanted to run the test to see what the actual real difference in runtime (if any) would be.

 

I am not an electrician so it’s completely possible I’m confused, but anyway, I feel that I found out what I wanted to find out, and shared it here for those who care.

To calculate the run time we are comparing the same devices at the same draw right?

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5 minutes ago, RadoStefanov said:

To calculate the run time we are comparing the same devices at the same draw right?

And different cells with different internal resistance figures and probably different temperatures of the device and the cells and maybe different amounts of grunge on the rechargeable cells? And probably not, I'm just speculating here, a very smart charger that can see what's happening in the cells and report that info to the user. 

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