A small overview of the three 18650 batteriesfrom the store Sofirn. Two of them are in a repacked wrapper with the name of their own brand and declared capacity of 3000 mAh and 3400 mAh with built-in charging via the microUSB port and one in the original factory one, from the DLG company at 3200 mAh.
It became interesting to compare these three betweena model and see if the same battery with the same capacity hides inside them. Especially for this, I chose them. We arrived in two plastic boxes specifically for the format 18650.
Externally, they look absolutely different:
- Sofirn 18650 3000mAh 3.7V - $ 4.85 (per piece)
- Sofirn (+ DLG) 18650 3200mAh 3.7V - 5.42 $ (per piece)
- Sofirn (+ microUSB) 18650 3400mAh 3.7V - 9.28 (per piece)
The first in line is the repackaged battery.black heat shrinkage, with declared capacity of 3000 mAh. It has the following dimensions: in length - 67.3mm, in diameter - 18.5mm. It weighs - 46.8g. Positive contact is the so-called "lantern".
Remove neatly top wrap.
Inside was hidden battery in whiteshrinkable, from the Chinese company DLG with a capacity of 11.744Wh and an average voltage of 3.67V. If we translate the capacity into more understandable values, we get 3200 mAh. A few words about the company itself. DLG it is a large Chinese company uniting inimagine a few separate units involved in the development and production of various batteries. The maximum capacity for them is 18650 at the given moment this is 3200 mAh. For the Chinese, this is not bad at all, they have practically approached such giants as LG, Panasonic.
There are no official datasheets on the Internet, at least I could not find it. There is only what sellers provide.
If you believe this information, then we havelow-frequency specimen, with a capacity of up to 3110 mAh at a discharge current of 0.2 ° C (0.64A). Designed for a maximum short-term discharge current of 6.4A, continuous - 3.2A.
To assess the actual internal capacity, spenttest for current discharge 0.2C (0.64A) with a lower voltage threshold - 2.5V. At the output I received 3047 mAh. A little did not reach the nominal values. When discharging current 1C (3.2A), the figure was slightly less - 2904mAh.
The following battery is sold without repacking,in the original white wrap DLG. Physical dimensions are: in length - 64.9mm, in diameter - 18.3mm. Weight - 46.1g. Unlike the previous model, on this capacity is not marked. In the same lot is sold as 3200mAh. Looking for some information, I realized that this copy has a slightly less capacity than stated, namely - 3150 mAh.
The visual differences between the two models from the DLG are minor (3150mAh and 3200mAh). Plus contact apparently soldered himself Sofirn.
Datashit again not official. Different sources indicate different information, but with respect to capacity it is unchanged - nominal 3150 mAh. minimum - 3050mAh. The maximum short-term discharge current is 6A, continuous - 1.5A.
Again, the test for determining the actual capacity spentdischarge current 0.2C (0.63A) and a minimum voltage of up to 2.5V. The output turned out - 2880mAh. And when discharging current 1C (3.15A) - 2674 mAh. Figures relative to the nominal are very different down. Even the last one showed more.
Well, the last for today, the battery in blackshrinkable with the inscription Sofirn, with a capacity of 3400 mAh and built-in charging through the microUSB input. Dimensions are: in length - 70.6mm, in diameter - 18.3mm. Weight - 47.8g. Due to the increased length, it does not fit into certain types of charges, for example, in a single canal and its analogues.
It differs from the other two not only in increased capacity, but also in the presence of built-in charging through the microUSB input.
After removing the outer shell, I found the familiarLG F1L1865 at 3350mAh Quite a popular model, which is widely used by many manufacturers in their external batteries (ZMI, Xiaomi, ARUN, Teclast, etc.).
Datashit official from the company LG. It shows that the nominal capacity is 3350 mAh (the minimum 3250 mAh when discharged with current of 0.2 C). The average voltage is 3.63 V, the maximum short-term discharge current is 4.8A, and the continuous current is 0.65A.
Through the built-in charging charges honestlyvery long, exactly 6 hours. This is due to the fact that the controller, which is installed inside, keeps the current at 0.55A from the very beginning and almost to the end. In principle, the battery can be charged without problems and directly, in conventional chargers (if of course it fits).
Capacity corresponds to the stated. When discharging with a current of 0.2C (0.67A), the output is 3302 mAh, and when discharging with a current of 1C (3.35A) - 3311 mAh. The voltage threshold is set slightly below normal 2.5V, specifically to determine at what level the built-in protection is triggered. In the first test, the disconnection worked at 2.43V, and in the second - at 2.20V.
My guesses about using the sameRepackaged batteries have not been verified. Although the capacity of all three is very close, inside the batteries are all different. All of them are low-current and suitable for use in flashlights, crib banks and other similar devices.