To be honest, I didn’t know the brand XTAR before. I started to Google this brand after I got this product. But this is not important, good products are beyond the size of the brand. Founded in 2006, XTAR is an electronic technology company that integrates R&D, production, sales, and service in Shenzhen. XTAR has been specializing in the development and manufacture of high-quality Li-ion batteries, smart chargers, and LED flashlights for over 12 years. With the high standards of quality control, XTAR products have achieved all major global certifications such as CE, UL, FCC, and RoHS. XTAR R&D department has obtained over 70 patents. According to the description of its website, the main products of XTAR are battery chargers and flashlights. The product I got—MC4S, is one of the popular products. In fact, there are many optional models of XTAR chargers, and some high-end models with digital displays such as the following. Why did I choose MC4S? As a ten-year-flashlight player, I’ve never been short of chargers. I have plenty of chargers with different styles, functions and sizes. However, there are several main points that this XTAR-MC4S attracts me: one is strong compatibility, and the other is Type-C interface power supply, making the charging more flexible. Well, let's unpack it first. The accessories in the package are very simple, the charger body, a Type-C charging cable, and a manual in 11 languages. First of all, this product left me the first impression is that it is small and light, and it can be compatible with a variety of batteries. Let’s take a look at the size first. 54.4mm*53mm*26mm The net weight is only 95.4g. Type-c interface power supply The first and the 4th battery slots can support 1A current fast charging, the 2nd and 3rd ones can support 0.5A charging current. Because of my career as a photographer, it can be said that I’m a super battery-consuming user. Therefore, my requirement for the charger must be at least 4-slot simultaneous charging, which can save charging time. I believe that many professional photographer friends have an unforgettable experience of getting up in the middle of the night to change the battery when they are shooting outside. As I’ve played flashlights for so many years, I have accumulated various types of batteries. Therefore, my focus on the charger is compatibility. Through practical tests, the 16340, 18350, 14500, 18650 and Eneloop NiMH batteries in my hand can be perfectly adapted. But it is a pity that the 21700 battery is too long to plug due to the protection circuit. (18650 with protection circuit can be tucked in, enough length) It is a pity that if the spring clip can be a little bit longer, the 21700 battery can also be charged. The manufacturer obviously also noticed this problem, so it was stated in the instruction manual that protected 20700 and 21700 could not be charged. The batteries compatible with this charger include: 10440, 14500, 16340, 17335, 17500, 17670, 18350, 18490, 18500, 18650, 18700, 20700, 21700, 22650, 25500, 26650, and 1.2V NiMH, NiCd batteries. To put it simply, it can basically charge all the batteries that can be put in. I think the second point that I love this charger is the type-c interface power supply. Because I use Huawei mobile phones, I can find the type-c charging cable everywhere, in the car, or on the desk. Therefore, the power supply of this charger can be perfectly solved. It is very practical to put it in the car as a spare charger. Moreover, it is small and exquisite, and it does not take up too much place in the armrest box. Last but not least, let’s take a look at the charging efficiency of this charger. Discharge two brand new 18650 batteries first. Then use 1A current to charge at the same time. The MC4S does not come with a USB conversion head, so I chose the IPAD charging head, and the output is 2.1A / 5V, which is in line with the charger manual. Start the timer. After 3 hours and 22 minutes, the MC4S showed full-charged, and the other charger was still trickled charging. By the way, this XTAR 18650 battery, nominally 2600mAH, actual 2780, not only does not have a virtual standard, but also slightly exceeds the standard. Summary: This charger is small, convenient, simple, and practical. It is very suitable for beginner flashlight players or as a backup player with charging needs. It has no fancy functions such as power detection and voltage detection, which reduces the possibility of damage and strengthens and also enhances portability. In addition, as long as the battery can be put in, all of them are compatible, making the charger returns to its original function.