Skip to main content

Queen Battery QB26650-2500 LiFePO4 cell's test + comparison with A123 Systems ANR26650M1B

Queen Battery QB26650-2500 is a 26650 size 2500mAh 50A LiFePO4 cell which supports up to 125A pulse discharge.
Queen Battery QB26650 2500mAh LiFePO4 cell's test + comparison with A123 Systems ANR26650M1B

The battery was bought from Queen Battery which is my reliable supplier of genuine cells and tested with ZKETECH EBC-A20 and a self-made battery holder. It's a PC-connected battery tester supporting 4-wire measuring and discharging at up to 20A.

I've used version 3.0 of my battery holder based on 0.5mm thick pure copper terminals

I've followed all the prescriptions of the IEC61960-2003 standard concerning battery's capacity measurement. Before each discharging cycle the battery was charged at standard charge current mentioned in its datasheet to charge end voltage. Before each discharging or charging i've held a 1-1.5hr pause. The environment temperature was 25±2°C. To be sure in results i've done each test minimum twice (usually 3-7 times).

Queen Battery QB26650 2500mAh

The heat shrink tube tells us only the model, capacity and nominal voltage.
Queen Battery QB26650 2500mAh LiFePO4 cell's test + comparison with A123 Systems ANR26650M1B

QB26650-2500 has probably the most detailed datasheet possible. Here are the most important specifications from it (pdf):
Typical capacity: 2500mAh (1C discharge!)
Minimum capacity: 2500mAh (1C discharge!)
Nominal voltage: 3.2V
Charge end voltage: 3.65V
Charge cut-off current: 50mA / 0.02C (100mA used)
Charge temperature: 045°C
Standard charge current:
015°C: 0.75A / 0.3C
1525°C: 1.25A / 0.5C
2545°C: 2.5A / 1C
Fast charge current:
015°C: 1.25A / 0.5C
1525°C: 2.5A / 1C
2545°C: 5A / 2C
Fierce charge current:
015°C: prohibited
1525°C: 5A / 2C (SOC≤40%, charge time <10min)
2545°C: 12.5A / 5C (SOC≤40%, charge time <5min)
Discharge cut-off voltage: 2.0V
Discharge temperature: -20–60°C
Max continuous discharge current: 50A / 20C
Max long pulse discharge: 75A / 30C for ≤60sec if cell's temperature ≤60°C
Max short pulse discharge: 125A / 50C for <10sec if SOC≥50% and <3sec if SOC<50% (cell's temperature ≤60°C)
AC impedance at 1KHz: ≤6mΩ at 50% SOC
Weight: 86g

Cycle life: аfter 2000 cycles at 2.5A charge/2.5A discharge (1C/1C) the capacity should be ≥2000mAh (80% of initial capacity).

DC IR at 2500mA in fully charged condition was 6.0±1.2mΩ (measured using EB Tester Software's Resistance test feature).

Measured dimensions: 26.6mm (diameter) × 65.1mm (length).

Measured weight: 84.93g.
Queen Battery QB26650 2500mAh LiFePO4 cell's test + comparison with A123 Systems ANR26650M1B

Queen Battery QB26650-2500 capacity test results (I've done each test 6 times).
Queen Battery QB26650 2500mAh LiFePO4 cell's test + comparison with A123 Systems ANR26650M1B
Surpriseee))) In fact it's a 2700mAh cell, not a 2500mAh one. Just look at the results - even at 20A discharge it remains above 2550mAh! The curves also look excellent! Nothing to add...


Comparison with A123 Systems ANR26650M1B

More than a year ago i tested and compared A123 Systems ANR26650M1B Grade A and Grade B cells using v.2.0 of my battery holder. It's a long time i'm using v.3.0 so it wouldn't be 100% fair to compare tests done using different holders, so i decided to re-test A123 cells in v.3.0 holder at 20A discharge. I did each test 4 times for each cell and here we are:
Queen Battery QB26650 2500mAh LiFePO4 cell's test + comparison with A123 Systems ANR26650M1B
Just look at those numbers! How close they are! ANR26650M1B Grade B has the highest capacity and QB26650-2500 has the lowest but the difference is only 30mAh!
The picture changes when we look at the energy - QB is the best and ANR26650M1B Grade A is the worst. The difference between them is as low as 138mWh!

Let's forget about numbers and look at the curves. ANR26650M1B's curves are good as they should be, but look at QB's curve. It's even better! It doesn't go below 3.0V most of the time (approx 65%) while A123 Systems' cells fall below it relatively quickly. I started to go into numbers again... Well, i just like the QB's curve more))

Now let's look at this comparison table
Queen Battery QB26650 2500mAh LiFePO4 cell's test + comparison with A123 Systems ANR26650M1B
A123 Systems' cells are winners in capacity and max continuous discharge rate while QB26650 takes the gold in energy and max pulse discharge rate. They all can be discharged down to 2.0V which is very good because most of LiFePO4 cells are limited by 2.5V.
Also Queen Battery's charge end voltage is standard 3.65V which means that it's compatible with the majority of BMS boards on the market.


Verdict

This was the most surprising test for me so far... I didn't expect such a brilliant performance from a Chinese cell... It's rated at 2500mAh but it's a 2700mAh cell! ANR26650M1B was considered as the best and out-of-comparison LiFePO4 cell by me until now... Well, each cell has its pros and cons mentioned in the table above so the choice is not obvious. The good news is that A123 Systems' cell has got a strong competitor with a lower price tag (send an email to QB, don't ask me, i'm not selling them).

Here is the video version of this review:
Queen Battery QB26650 2500mAh LiFePO4 cell's test + comparison with A123 Systems ANR26650M1B

Check out my YouTube channel for batteries, chargers and other stuff reviews.

Popular posts

Samsung 50E capacity test - 5000mAh or not?

Samsung INR21700-50E is a 21700 size cell which is being sold as 5000mAh one while in its official datasheet the capacity is mentioned as "Min. 4900mAh". I've tested it to find out it's real capacity.

The battery was bought from my reliable supplier (Queen Battery) and tested with ZKETECH EBC-A20 and a self-made battery holder. It's a PC-connected battery tester supporting 4-wire measuring and discharging at up to 20A.

I've used version 3.0 of my battery holder based on 0.5mm thick pure copper terminals

I've followed all the prescriptions of the IEC61960-2003 standard concerning battery's capacity measurement. Before each discharging cycle each battery was charged at standard charge current mentioned in its datasheet to charge end voltage. Before each discharging or charging i've held a 1-1.5hrs pause. The environment temperature was 23.0-24.5°C. To be sure in results i've done each test minimum twice (usually 3-4 times).

Samsung INR21700-50E

The c…

3500mAh 18650 Li-ion cells' discharge capacity test (Sanyo NCR18650GA vs Panasonic NCR18650GA vs LG MJ1 vs Samsung INR18650-35E)

Hi guys! I’ve got four 3500mAh batteries from top manufacturers. I’ve tested and compared them. I think it’s interesting not only for me, but also for you, the guy who is reading this:)

The cells were bought from Queen Battery, a Chinese supplier of genuine batteries, who specializes mainly on EV and eBike market. Queen Battery has a branch in Europe, but they also work with customers from Americas, Russia, etc…

As always, I've tested with ZKETECH EBC-A20 and a self-made battery holder. It's a PC-connected battery tester supporting 4-wire measuring and discharging at up to 20A.

I've followed all the prescriptions of the IEC61960-2003 standard concerning battery's capacity measurement. Before each discharging cycle each battery was charged at standard current mentioned in its datasheet to 4.2V (cut-off at 0.1A, which is the lowest supported by EBC-A20). Before each discharging or charging i've held a 1-1.5hrs pause. The environment temperature was 20-25°C (21-23°C …

Li-ion 21700: LG M50 5000mAh vs Samsung 48G 4800mAh discharge capacity test

Hi guys! I've tested two high capacity 21700 cells - LG M50 (5000mAh) and Samsung 48G (4800mAh). The latter i had already tested before and the re-testing of another cell showed almost no difference with previous test results. The M50 is a new cell which is being sold as 10A one, but in its datasheet the maximum discharge current is mentioned as 7.28A. Nevertheless i've also discharged it at 10A to look at it's behavior.

The cells i've bought from Queen Battery.

As always, I've tested with ZKETECH EBC-A20 and a self-made battery holder. It's a PC-connected battery tester supporting 4-wire measuring and discharging at up to 20A.

I've used the v2.5 of my battery holder

I've followed all the prescriptions of the IEC61960-2003 standard concerning battery's capacity measurement. Before each discharging cycle each battery was charged at standard current mentioned in its datasheet to charge end voltage (4.2V) (cut-off at 0.1A, which is the lowest supported…

LG M36 vs Samsung 36G capacity test - 3600mAh or just marketing?

The first 3600mAh Li-ion battery in 18650 format appeared 4-5 years ago. It was Panasonic NCR18650G. But it disappeared from the market very quickly and since then there was no 3600mAh cell you could buy (except fakes on eBay). Now two of top manufacturers, LG and Samsung, offer their cells, which are being sold as 3600mAh ones - LG INR18650 M36T and Samsung INR18650-36G. Let's check if they are real 3600mAh ones.


As always the tests were done using ZKETECH EBC-A20, which supports up to 20A discharge, 4-wire measurement and is PC-connected.

I've upgraded my battery holder to the version 3.0

This time i've used thicker (0.5mm) pure copper strips (9mm and 11.5mm wide). The parts which contact with the cell are rised a bit to provide reliable connection when a cell with deep placed contact(s) is held.

I've followed all the prescriptions of the IEC61960-2003 standard concerning battery's capacity measurement. Before each discharging cycle each battery was charged at standa…

Sony VTC6 - a 3000mAh/30A monster in 18650 size

Sony US18650VTC6 (or just VTC6) is a high drain 18650 size Li-ion cell which supports discharge rate up to 15A if no temperature control is used and up to 30A with 80°C temperature cut.

The battery was bought from my reliable supplier (Queen Battery) and tested with ZKETECH EBC-A20 and a self-made battery holder. It's a PC-connected battery tester supporting 4-wire measuring and discharging at up to 20A.

I've used version 3.0 of my battery holder based on 0.5mm thick pure copper terminals

I've  all the prescriptions of the IEC61960-2003 standard concerning battery's capacity measurement. Before each discharging cycle each battery was charged at standard charge current mentioned in its datasheet to charge end voltage. Before each discharging or charging i've held a 1-1.5hrs pause. The environment temperature was 23.0-24.5°C. To be sure in results i've done each test minimum twice (usually 3-4 times).


Sony US18650VTC6

The cell is marked as
SE US18650VTC6 C6
G 0400743YF2…

LG F1L vs Panasonic NCR18650B capacity test - the 3400mAh Li-ion cells' battle

Panasonic NCR18650B is probably the most popular Li-ion battery of 18650 size. Though it's rated at 3350mAh it's usually listed as 3400mAh on suppliers' sites as well as LG F1L. They are both 3350mAh cells with 4.87A maximum discharge rating so they must be compared.
I've tested both cells at 0.65A (0.2C), 2A and 5A.

As always the tests were done using ZKETECH EBC-A20, which supports up to 20A discharge, 4-wire measurement and is PC-connected.
Using version 3.0 of my battery holder based on 0.5mm thick pure copper terminals
I've followed all the prescriptions of the IEC61960-2003 standard concerning battery's capacity measurement. Before each discharging cycle each battery was charged at standard current mentioned in its datasheet to charge end voltage (4.2V) (cut-off at 0.1A, which is the lowest supported by EBC-A20). Before each discharging or charging i've held a 1-1.5hrs pause. The environment temperature was 23.5-24.5°C. To be sure in results i've don…