In-Depth Review of XTAR 18650 3600mAh Li-ion Battery

Apr 07, 2023 | XTAR

Today I will introduce a new company batteries Xstar 18650 3600mAh on my channel. This model will be the first in which the manufacturer declared a capacity of 3600 mAh for these Li-ion batteries.

Specifications of XTAR 18650 3600mAh

The specification is very concise. It has a rated voltage 3.6 Volts, 3600mah maximum capacity, continuous discharge current of 10 amps and declared resource more than 500 cycles of charge-discharge. Protection board provides multi-protection, namely from over-charging, over-discharging and short circuit.

This battery is low self-discharge. White color inscription is lettered on the dark blue shrink film smoothly.

There is a warning that these batteries cannot be made dismantled, thrown into the fire, and so on. Batteries are made in China.

The positive terminal rises above the top edge of the battery by about 1 mm, and the negative terminal is flat ground. The first battery weighs 49.2 grams. The second sample is slightly heavier 49.44 grams. The battery diameter is 18.27mm, and the length is 69.17mm.

The internal resistance of batteries was measured at transmission alternating current with a frequency of 1 kHz. The first sample is 35.8mΩ with a voltage of 3.61 volts. And the second sample is 35.7mΩ with a voltage of 3.58 volts.

Performance Test of XTAR 18650 3600mAh

I tested these batteries on a chemical analyzer current source ACK- The test is focused on the circuit. The first stage is a discharging with a current of 720mA to a low voltage threshold of 2.5 volts so that we clean the residual charge that was in batteries when they were made. The next stage is a pause of 1 hour as recommended by GOST for testing lithium-ion batteries. the third step is a charge current of 1.8A and then the upper threshold voltage of 4.2 volts. The 4th step is up to charge at a constant voltage of 4.2 Volts falling current from 1.8A to current cutoffs of 100mA. Next, step 5 is a pause of 1 hour and after that, we spend a discharging current of 720mA, i.e. 20 percent of estimated battery capacity, to the lower voltage threshold of 2.5 volts, while every minute will be carried out equivalent series resistance measurement.

Batteries start testing like this in the picture.

Let’s analyze the results obtained from battery testing. The discharge characteristics of XTAR batteries are presented when discharging currents from 720mA to 10A. Vertical value is the voltage in volts, and horizontally the amount of charge given in milliamp-hours. This slide also presents the discharge curves of the same battery vertically voltage in volts and horizontally the amount of energy delivered in miliwatt hours during testing batteries.


The following results were obtained according to the data of the thermal imager at a discharge current of 7 amperes, which is two capacitance values. The temperature was 60.7 degrees Celsius for low-current batteries, this is such a threshold that, in general, it is undesirable to exceed when discharging with a current of 10 amperes. Heating at the end of the test to 78 degrees Celsius, I will say again that for a low-current battery this temperature value is high.

The final test table is presented in the following picture.

In the second column, indicators are presented for which battery characteristics were evaluated. The third column is the BOM of XTAR declared on their official website. The 4-5 Columns are the test results and the sixth column is surface temperature.

The indicator shows the battery weight was 49.2 g and 49.44 g. The second sample has a difference in weight, which indicates that the second sample has more mass of electrodes. The greater the mass of the electrodes, in general, the more accumulated charge and energy can give the battery. And we see over further tests that all the capacity values of the second battery were higher than the first one.

In the third column, the average value for equivalent series resistance of the batteries is 53.7 mΩ for the first sample and 48.6mΩ for the second sample.

In the fourth line, the internal resistance of batteries when passing alternating current frequency 1 kHz is the first sample 35.8 milliohm, and the second 35.7, very close indicators. I can assume that relatively high internal resistance is also related to the fact that in this case, the device also measures the resistance of electronic components which are included in the protection.

Fifth line, battery capacity measured Inflow 720 milliamps to Low Threshold voltage 2.5 volts, for the first sample amounted to 3471mAh and the second has 3545mAh, a difference from the values given by the brand was 2 percent. Well, in general, manufacturer rather modestly presented battery specifications on the site, only the main characteristics are indicated here. So I assume that the value of 3600mAh is the maximum possible for two factors. But the minimum value, as a rule, many manufacturers indicate 150-200mAh lower than the maximum. Therefore, if we assume that, for example, the minimum value is indicated as 3300 and the maximum is 3450, that is, plus 150 milliamp hours. Therefore, if the range is also minimally reduced by 150, then it turns out that both samples fit into this range of the minimum and nominal capacitance values 3450-3600. The value in the test result is very good, especially for the second sample, this is perhaps the highest capacitance of Lithium battery 18650. 3545mAh! This is an excellent indicator of the amount of energy delivered.

The value turned out to be slightly lower than 12.35 and 12.6 Wh in further periods of 7A to 12A. The given amount of charge and the energy of the batteries, at discharge currents of 3.5, 7 and 10 amperes, are indicated xtar 18650 outputs with a declared capacity of 3600mAh. These are protected high-capacity batteries.

Capacity 3470+ milliamp hours, capacity 12.3+ watt-hours, and maximum continuous discharge current 7 amps – 10 amps, these are three capacity values with temperature control, and discharge completion at 60 degrees Celsius on the surface of the batteries.

XTAR 18650 3600mAh battery can be applied in various of power banks, LED flashlights, children toys and so on. You can buy these batteries on their official store, Aliexpress, and maybe your local stores.

Here you can watch the full review video in Rusian language.


* indicates required