thunderheart
100 W
Original article: https://www.thunderheartreviews.com/2018/11/trustfire-14500-900mah-trust-or-not.html
Everyone knows that UltraFire and other *Fires are Chinese brands who sell re-wrapped crap marked as 6000mAh, 8800mAh or even 12000mAh Li-ion cells but TrustFire doesn't use crazy ratings like that. 14500 is the same well-known AA size - 14mm in diameter and 50mm long. 900mAh looks pretty real for that size so let's check is it real or it's just another *Fire.
Tests were done using ZKETECH EBC-A20, which supports up to 20A discharge, 4-wire measurement and is PC-connected.
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 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 done each test minimum twice (usually 3-4 times). Battery was bought from Queen Battery.
TrustFire 14500 900mAh
TrustFire has an official website: www.trustfire.com, but i wasn't able to find any datasheet for this cell. Each cell has a unique marking but i don't know what it means. The cell which i've tested has the following marking: IC21AFKUGY3H.
Look at the mention on the shrink tube - "Precise digital proection circuit built-in". I didn't believe it and i checked the presence of protection PCB after having done the tests. As i told, there is no datasheet and the only info available from the manufacturer is the 900mAh capacity and "Supports until 1000 recharges" mention on its website, which is not true of course
I used the following values in my tests:
Rated capacity: 900mAh
Nominal voltage: 3.7V
Standard charge current: 630mA (0.7C)
Charge end voltage: 4.20V
Charge cut-off current: 100mA
Discharge cut-off voltage: 2.5V
DC IR in fully charged state was ~35mOhm (measured using 900mA current)
The measured weight of my cell is 19.89g and it's 14.0mm in diameter and 49,1mm long
Capacity test results:
Frankly, i was surprised! It did almost 900mAh at 0.2C!!! 885mAh is just an excellent result for a 14500 cell. Even at 2A discharge rate it showed 735mAh result! I tested it at up to 5A to find the limit after which a voltage sag will appear but i wasn't able to find it. All the curves from 0.18A to 5A look beautiful! It's impressive, but i'd not recommend to discharge it at more than 3A because it would be too much for such a little cell and the cycle life will suffer badly.
PROTECTED OR NOT?
Now let's see what's there with built-in protection which the manufacturer claims it has. First i checked their website and found 2 versions of TrustFire 14500 900mAh battery - with protection and without. It was strange to see that TrustFire used the photos of protected cells on both pages
Can you see that yellowish negative pole? it's the contact terminal of protection PCB which is placed on the cell's negative pole. If you look better you'd see the groove between the cell and the PCB assembly.
Now let's compare official photos with the cell which i've got:
There are 2 differences: 1. my cell's negative pole is not yellowish and 2. there is no groove and additional 2mm space after "900mAh", so it's obvious that i've got the version without protection PCB but to be 100% sure i decided to discharge it down to 1.9V - a value which is far below the overdischarge detection voltage of any protection PCB. I did it at 1A and there was no protection to stop overdischarging, so my thoughts were confirmed on practice.
CONCLUSION
This cell surprised me a lot! Excellent capacity and performance even at 5A in 14500 size! 885mAh at 0.2C is just a bit below the 900mAh declared so i think we could say the manufacturer doesn't lie here. On the other hand TrustFire decided to save a couple of cents by using the same heat shrink tube they use on protected cells which claims the battery is protected. In fact it's not! So be careful when buying a TrustFire! By the way, there is no mention about protection on the product page on my supplier's (Queen Battery) website.
The are 2 answers to the question trust or not: trust the capacity rating but watch out for the presence of protection PCB.
Here is the video version of this review with size comparison to an AA battery:
Check out my YouTube channel for batteries, chargers and other stuff reviews.
I've recently launched my blog where you can find all my reviews in one place. Every new test/review will be first published on YouTube and in the blog. I'll be happy to see new subscribers, comments, suggestions and just your thoughts.
Everyone knows that UltraFire and other *Fires are Chinese brands who sell re-wrapped crap marked as 6000mAh, 8800mAh or even 12000mAh Li-ion cells but TrustFire doesn't use crazy ratings like that. 14500 is the same well-known AA size - 14mm in diameter and 50mm long. 900mAh looks pretty real for that size so let's check is it real or it's just another *Fire.
Tests were done using ZKETECH EBC-A20, which supports up to 20A discharge, 4-wire measurement and is PC-connected.
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 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 done each test minimum twice (usually 3-4 times). Battery was bought from Queen Battery.
TrustFire 14500 900mAh
TrustFire has an official website: www.trustfire.com, but i wasn't able to find any datasheet for this cell. Each cell has a unique marking but i don't know what it means. The cell which i've tested has the following marking: IC21AFKUGY3H.
Look at the mention on the shrink tube - "Precise digital proection circuit built-in". I didn't believe it and i checked the presence of protection PCB after having done the tests. As i told, there is no datasheet and the only info available from the manufacturer is the 900mAh capacity and "Supports until 1000 recharges" mention on its website, which is not true of course
I used the following values in my tests:
Rated capacity: 900mAh
Nominal voltage: 3.7V
Standard charge current: 630mA (0.7C)
Charge end voltage: 4.20V
Charge cut-off current: 100mA
Discharge cut-off voltage: 2.5V
DC IR in fully charged state was ~35mOhm (measured using 900mA current)
The measured weight of my cell is 19.89g and it's 14.0mm in diameter and 49,1mm long
Capacity test results:
Frankly, i was surprised! It did almost 900mAh at 0.2C!!! 885mAh is just an excellent result for a 14500 cell. Even at 2A discharge rate it showed 735mAh result! I tested it at up to 5A to find the limit after which a voltage sag will appear but i wasn't able to find it. All the curves from 0.18A to 5A look beautiful! It's impressive, but i'd not recommend to discharge it at more than 3A because it would be too much for such a little cell and the cycle life will suffer badly.
PROTECTED OR NOT?
Now let's see what's there with built-in protection which the manufacturer claims it has. First i checked their website and found 2 versions of TrustFire 14500 900mAh battery - with protection and without. It was strange to see that TrustFire used the photos of protected cells on both pages
Can you see that yellowish negative pole? it's the contact terminal of protection PCB which is placed on the cell's negative pole. If you look better you'd see the groove between the cell and the PCB assembly.
Now let's compare official photos with the cell which i've got:
There are 2 differences: 1. my cell's negative pole is not yellowish and 2. there is no groove and additional 2mm space after "900mAh", so it's obvious that i've got the version without protection PCB but to be 100% sure i decided to discharge it down to 1.9V - a value which is far below the overdischarge detection voltage of any protection PCB. I did it at 1A and there was no protection to stop overdischarging, so my thoughts were confirmed on practice.
CONCLUSION
This cell surprised me a lot! Excellent capacity and performance even at 5A in 14500 size! 885mAh at 0.2C is just a bit below the 900mAh declared so i think we could say the manufacturer doesn't lie here. On the other hand TrustFire decided to save a couple of cents by using the same heat shrink tube they use on protected cells which claims the battery is protected. In fact it's not! So be careful when buying a TrustFire! By the way, there is no mention about protection on the product page on my supplier's (Queen Battery) website.
The are 2 answers to the question trust or not: trust the capacity rating but watch out for the presence of protection PCB.
Here is the video version of this review with size comparison to an AA battery:
Check out my YouTube channel for batteries, chargers and other stuff reviews.
I've recently launched my blog where you can find all my reviews in one place. Every new test/review will be first published on YouTube and in the blog. I'll be happy to see new subscribers, comments, suggestions and just your thoughts.
