It sounds simple to use lithium iron phosphate batteries in series and parallel, but some simple rules should be followed to avoid unnecessary problems.

① do not mix different brands of lithium batteries, different capacities or new and old lithium batteries, and choose batteries with the same performance.

② when the lithium battery pack is used in series, the same type of battery shall be used. Pay attention to the polarity of the battery. If the polarity of one battery is reversed, the voltage of the whole battery will be reduced rather than increased.

③ generally, the use of series and parallel connection of lithium batteries requires the matching of lithium battery cells. The matching standards are: the voltage difference of lithium battery cell ≤ 10mV, the internal resistance difference of lithium battery cell ≤ 5m Ω, and the capacity difference of lithium battery cell ≤ 20mA.

④ when two groups of lithium iron phosphate batteries are connected in parallel, attention should also be paid to the internal resistance. In a word, if the internal resistance of two batteries in parallel is similar, they can be directly connected in parallel, and the internal resistance is quite different, so it is better to discharge separately.

⑤ pay attention to the consistency of the battery when the lithium iron phosphate battery is connected in parallel, because the poor consistency of the parallel lithium battery will not charge or overcharge in the charging process, which will damage the battery structure and affect the life of the whole battery.

The purpose of parallel connection of lithium iron phosphate batteries is to increase capacity. Therefore, parallel charging of lithium batteries has different design characteristics compared with single lithium battery, which is mainly reflected in the consistency of charging current design and parallel battery. Whether in series or parallel, the output power of lithium battery pack increases.