How do you know if the electric bike battery you receive is good quality?

How do you know if the battery on your electric bike you receive is good quality? Today Sobowo will help you to know more about the lithium battery. It is a good way for newbie to identify the quality of the battery you purchase.

Nowadays there are a variety of lithium battery on the market, different brands, models, material, price, and capacity.

Lithium batteries are mainly divided into: LFP, LNO, LMO, LCO, NCM, NCA. We use NCA.

We use 18650. 18 stands for the diameters of 18 milimeters; 65 stands for the height of 65 milimeters; 0 stands for cylinder. You will see the brand, LG, and some are Samsung or other unknown brand names showed on the cells, 2600mAh or 3200mAh, the voltage is 3.6V, max charge voltage is 4.2V. A lot of bad reputation suppliers will use unknown brand battery cells instead of famous brand cells, but with high prices. They are sure that no one will open the battery box to identify the truth.

The 48V battery voltage should be 45V to 54V measured with a multimeter. Generally, it is 54V when fully charged.

We can calculate the battery capacity. Sometimes we find that some customers have previously received quotes from some suppliers with a lot of battery capacity that is unreasonable. This is unprofessional. But because they don't know how to calculate capacity, they often don't know that capacity is wrong. Today I am going to show you how to calculate the capacity. The space in different battery cases are not the same, some can fit 52 units cells, some can fit 65 or 78 units. Each 18650 cell voltage is 3.6V or 3.7V. If one battery voltage is 48V, 48V is divided by 3.7V, 3.7 is each battery cell voltage, is 13.13 means 13 series. If one battery case can fit 52pcs cells, 52 is divided by 13 is 4. 4 means 4 parallel. 13 series times 4 parallel is 52 units battery cells. Each battery capacity is 2600mAh or 3200mAH(3500,2500,2900). 3200mAh times 4 parallel is 12.8Ah. So the battery capacity is 12.8Ah. If one battery case can fit 65 units battery cells, 3200mAh times 5 parallel is 16Ah. Can you learn it?

Let’s talk about the BMS. BMS is the abbreviation of BATTERY MANAGEMENT SYSTEM. What’s the function of BMS? The main function of BMS is to improve battery utilization, prevent battery overcharge and overdischarge, prolong battery life, and monitor battery status. In layman's terms, it is the system that manages, controls and uses the battery pack. The three core functions of the BMS are battery monitoring, state-of-charge estimation, and battery balancing. So a good BMS is crucial to battery quality. The quality of BMS in the market is uneven. If the quality is not good, it will cause many problems.

For example, unbalanced discharge of batteries can lead to overheating and, in severe cases, burning or even explosion.

If the technical principle of short-circuit protection is unreasonable, the metal of the connector will melt during short-circuit protection.

If the battery discharges unevenly, the battery is not durable and easily damaged.

The batteries produced by some manufacturers have many problems, such as disordered BMS wiring, and the wiring harness is squeezed by the battery box, which will seriously lead to inability to charge and discharge.

Poor wiring harness welding will lead to false welding, unreliable connection, heat.

The poor quality of the nickel sheet will lead to increased internal resistance and heat, and the heat will be out of control in serious cases.

If the support material is not good, it will heat and melt.

Today SOBOWO simply teaches you the knowledge of batteries, which may be a bit difficult to understand. If necessary, you can contact us or leave us a message for more details.