Many engineers who want to study the assembly of lithium batteries do not know how many strings and parallels a set of lithium batteries must, so we can share this problem with you today. Okay, let’s take a look at the calculation of how many strings a set of lithium batteries must have. How many batteries do you need in a few ways?

**Calculation method one:**

It’s very simple, the voltage is increased in series, and the capacity is increased in parallel. The ternary lithium standard stipulates that the voltage is 3.7v, full of 4.2v, three strings are 12v, and 48v must have four three strings, but the lead-acid battery of electric vehicles is the most fully charged, 58v. Therefore, the lithium battery must also be about 58v, so it must be 14 strings to 58.8v, 14 times 4.2, and the iron-lithium battery is fully charged to about 3.4v, four strings must be 12v, 48v must be 16 strings, and so on, 60v must be 20 series, the same model and the same capacity in parallel, two 10ah batteries in parallel are 20ah, 48v ternary lithium requires 14+14 10ah batteries, and the last 14 connected in series will form a 48v20ah lithium battery.

**Calculation method two:**

In fact, it is very simple. For example, 48 volts usually refers to voltage. Generally speaking, ternary lithium batteries usually refer to 48 divided by 3.7. The thirteen strings and fourteen strings are basically 48 volts, and the thirteen strings use 54.6 volt battery charger, fourteen strings are charged using 58.8 volt battery charger. So that 20 amp hours usually refers to the capacity of the battery. If it is a single 18650 cell with a capacity of only 2000 mAh, this is 2 amp hours each, and ten cells together are 20 amp hours. The whole set of batteries is 14 strings multiplied by 10 cells = 140 cells.

60 volts is the same principle. Generally speaking, 16-17 strings are basically 60 volts. If it is 60 volts and 20 amps, the capacity of a single cell is 2000 mAh, which is 16-17 times 10, 160-170 a cell. It should be clear here

The iron-lithium battery is the total voltage divided by 3.2. For example, 48-volt iron-lithium usually refers to 15-16 strings, and the algorithm is basically the same, except that iron-lithium has more strings of batteries than ternary lithium, and then an iron-lithium battery. The charging voltage of ternary lithium and ternary lithium is basically different. When you buy, you should communicate with the company’s battery manufacturer.