I also changed the discharge current between the two tests. I am pretty sure changing the termination voltage to anything under 1 volt will not make a difference. The electronics simply shut them down just a little under 1.1 volts. The MC3000 would change its display to “No Battery” before it got to 0.9 volts. Nothing more to be pulled out once that happens.
Or, if there is, you can’t get to it…
【Updated】Tests of XTAR 1.5V AA 4150mWh Li-ion battery on XTAR AA 4150mWh - Akkuvergleichstest.de. “With 500mA discharge, we test this xtar 1.5V AA battery capacity of 2518mAh and energy of 3574mWh. This impressive record beats all NiMH batteries, alkaline batteries and other 1.5V output Li-ion batteries that we have tested so far.”
There is the comparison list of some 1.5V AA Li-ion batteries from different brands:
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That is a pretty impressive result! 
Idk, i still believe the video that tested them and got 1.9ish mah at 500ma load. I do not care what is left in the cell after 1.1v drop, i can not use it, so for practical purposes it does not exist.
the guy in the video you linked simply did not understand this battery, therefore he set the cut off voltage of his so called “measurement” to 1.1V, which resulted in missing 20 % of the capacity …
1.1V are not “useless” in this sense, because devices made for Alkaline and NiMH do NOT turn off at 1.1V, of course ! … so that capacity DOES exist …
the results Xtar quoted today were measured by guys who did thousands and thousands of charge / discharge cycles with 1.5V Li-Ions and their set up looks like this …
whereas the guy in the video you linked put the Xtar battery in an AA to D-size adaptor and then attached alligator clips to that … creating lots of contact resistances between battery and measuring device, which of course additionally influenced his unqualified “measurement” …
but I think, it’s hopeless to try to explain that to you again …
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For these cells anything below just under 1.1 Volts is useless as the BMS cuts them off at just under 1.1 volts. So though energy may be available, it can’t be accessed.
BTW, I got a consistent ~2280 mAh for four cells , but I had to use a 250 mA discharge rate to get there. I was getting closer to 1900 mAh at 0.3 amps and 1.1 volt cutoff/ I will have to rerun them at half an amp. The problem is setting the cutoff on the MC3000. If set too low, the BMS cuts off the cell and it ends up showing as no battery… and then drops the results. It is a trade off between setting it too high and maybe leaving a ew mAh in the cell, or too low, and losing the results. Too bad I don’t speak German… I would like to try to duplicate the tests rom the video.
But for me, still, the bigger problem (for the application I would use them in) is the relatively high self discharge rate.
Of course this is less of a problem when just using them to capacity quickly and recharging them regularly.
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Sounds like you are measuring wrong as well. Once the battery steps down from 1.5V to 1.1V there is still a significant amount of energy available! You have to measure until it turns off completely.
Even more under high load:
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I did measure to cut off. Did you read this part:
Not sure how to get around this. I think this is the same for any of my charger/analyzers.
One of the reasons I got the ZB206+ Battery Tester. It retains the discharge capacity when the battery cuts out. 2 ‘trick’ device, but they are useful tricks.
Got mine this morning will try them in my devices, will see how they perform. My biggest AA usage is in RC toys.
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I did some calculations regarding possible ratios of capacity at 1.5V and at 1.1V …
currently the ratio of these Xtar AA is 80 % at 1.5V and 20 % at 1.1V …
1 - 2 % at 1.1V like some brands do, is too less …
on the other hand 20 % at 1.1V is not really necessary …
but of course it allowed to claim “2500 mAh” of total capacity …
with less capacity at 1.1V there would be more energy at 1.5V :
2200 mAh at 1.5V would result in additional 250 mAh at 1.1V = 2450 mAh in total
2250 mAh at 1.5V would result in additional 180 mAh at 1.1V = 2430 mAh
2300 mAh at 1.5V would result in additional 100 mAh at 1.1V = 2400 mAh
(all at a load of 500 mA, based on the measurements by akkuvergleichstest.de shown above …)
in these cases the “2500 mAh”, presumably wanted for advertising reasons, would have been missed, but there would be more capacity at the desirable level of 1.5 Volt …
although the energy at 1,1V is not “lost” in that sense, but is there and can be measured and is not totally useless, I guess many would prefer another ratio, more in favor of the 1.5V …
I said it before awhile back, and I think it deserves repeating:
IMO the functioning purpose of this kind of product IS the 1.5v and at least reasonable current output. When they drop to 1.1v that is a signal that they are out and they are no longer able to do their job at 1.5v. If the device NEEDS 1.5v it is likely no longer working. IF it can function properly at 1.1v you may as well use a good NiMh for more capacity and MUCH cheaper, plus the ‘low voltage signal’ is built into it’s chemistry.
It’s irrelevant HOW MUCH is still remaining at 1.1v if that capacity+current cannot be used by the device. It’s like counting eggs and believing they are really chickens.
many of such devices still work with 1.1V, because they are originally designed for Alkaline batteries too and therefore - of course - do not simply shut off already at 1.1V …
with NiMH, from the beginning there is a decline of the voltage to a much lower level compared to 1.5V Li-Ion … which often means not as good performance as well, for example in flashlights, but in other devices, too …
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NiMh do fall to ~ 1.2v with use but tend to hold pretty steady there for a long time, longer than alkaline.
Seems you are arguing 1.1v is OK, but 1.2v is not.
I agree, 1.5v gives better performance in some devices than 1.2v. THAT is what the 1.5v batteries are for.
But if better performance is the goal, I don’t understand supporting the lower performance at 1.1v, no matter how long it does, or does not last.
I think it is pretty useless if it cannot be accessed. The BMS/converter shuts off at right around 1.1 volts. So regardless of whether there is any energy left in the cell, it can’t be used. The very definition of useless.
# FAQs about XTAR rechargeable 1.5V AA 4150mWh battery
We collected some frequently asked questions about xtar 1.5V AA 4150mWh battery. For example, what’s the internal structure of this battery? What’s the difference between mWh vs mAh? How to calculate the “4150mWh”? Can it be charged by regular 18650 battery chargers…
Welcome to check more details on our website:
In 1,5V li-ion AA type batteries I hate that there is no indication that they will run out. They just do it suddenly and device stops working. No time to react. In this case you have visible indication, because most devices still works but low battery sign apeears.
In my usecase - the radiator thermostats often need 1,5V, but still runs on lower end. In this case I’ll get info from thermostat to replace battery and I have time to do it. Instead they will turn off and can be left in open valve state.
For me it is great!
Update, the door lock does not work at the 1.1V stage of the cell, but no matter really because the cells lasted through the entire winter and spring. I’ll just be sure to top them off with each change of the season.
a correction of a little mistake in those “FAQs” :
there is written :
How to calculate the “4150mWh” ?
“… Convert the capacity mAh to mWh, it is 2500mAh x 1.5V=3750mWh …”
that is not quite correct, because this AA does not deliver 100 % of its capacity at 1.5V, but just 80 % and the rest of 20 % at 1.1V … (@ 500 mA)
so the correct calculation of the energy is :
2000 mAh (= 80 %) x 1.5V + 500 mAh (= 20 %) x 1.1V = 3550 mWh
obviously this ratio of 80 % to 20 % was chosen to reach the impressive “2500 mAh” …
a ratio of 90 % to 10 % would have led to a total capacity of “just” 2450 mAh …
a ratio of 95 % to 5 % would have resulted in a total capacity of around 2400 mAh …
(the same strategy has been used in case of the new “white-blue” AAA 1.5V Li-Ion in order to reach the impressive “1000 mAh” … again a ratio of 80 % to 20 % …)
I think, most customers would prefer a higher percentage of capacity at 1.5V … even if it would mean a little less “impressive” total capacity scores …
some brands have a 1.1V stage of just 1 - 2 % at the end of the capacity, that of course clearly is too little …
but it could well be less than 20 % …
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