The notebook battery core mainly adopts the 18650 specification, which is the length of the battery core is 65mm and the diameter is 18mm. This battery core is widely used in the notebook computer battery, and of course, some laptop battery is subject to the shape and volume constraints and uses other types of batteries. core. 
There are three types of batteries used in notebook computers: 1. Ni-Cd batteries, 2. Ni-MH batteries, 3. Li-Ion batteries; they are generally expressed as: Ni-Cd NI-CD, Ni-MH NI-MH, and Li-Li. 
When buying or replacing a laptop battery, the "cell" may be new to many users. First of all, the battery and the battery are two concepts. A battery is made up of several small units that are slightly larger than the thumb, cylindrical, about 6-7 cm high, and 18 mm in diameter. The professional name is 18650. Sanyo, Samsung, BAK, and Tiansheng TS are the largest manufacturers. The batteries, like a small battery, go through a series combination and are the batteries we see. 
Then talk about how to judge the battery is a few cores: one way to pull the battery down to see the number of his contacts, there are several core. However, this is the method of "adviser". Let's take a look at how "Cao Chong" is called: Look at how much your battery is nominally v, such as 14.4v, then divide by 3.6 to get 4, which proves that 4 batteries are connected in series. Then look at the capacity of the entire battery, such as 4400mAh, then prove that there are two sets of tandem battery groups mentioned above, because those small battery capacity is 2000-2200mAh or more, the two groups must be together to reach 4400mAh. Based on these two judgments, the battery is 4 x 2 = 8 cores. If you want to have a long battery life, you can use a high-capacity battery. You can use 2200mAH-3000mAH.