Avoid putting lithium batteries in parallel without any protection against voltage disparity or self balancing currents. But for your question here is maybe a lead of answer : electronics. com/questions/289450/.
Can you put lithium batteries in parallel without protection?
@Tagadac You said not to put lithium batteries in parallel without any protection. My question described a scenario where three sets of 'four 18650s connected in parallel' are connected in series.
What is a parallel lithium battery pack?
According to the parallel principle, the current of the main circuit is equal to the sum of the currents of the parallel branches. Therefore, a parallel lithium battery pack with “n” parallel batteries achieves the same charging efficiency as a single battery, with the charging current being the sum of the individual battery currents.
What is a battery protection board?
Hardware-type protection board: Use special lithium battery protection chip, when the battery voltage reaches the upper limit or lower limit, the control switch device MOS tube cut off the charging circuit or discharging circuit, to achieve the purpose of protecting the battery pack. Characteristics: 1.
Cells in multi-packs must be matched, especially when used under heavy loads. (See BU-803a: Cell Mismatch, Balancing). The single-cell configuration is the simplest battery pack; the cell does not need matching and the protection circuit on a small Li-ion cell can be kept simple.
Should I Put 4 batteries in parallel?
If the cost and risk don't warrant it then just parallel 4 batteries and hope for the best with a single BMS. The cells you put in parallel are no longer considered 4 cells in parallel but are now considered one cell with more capacity and able to source more current safely (if your bus is up for it.)
3.) If the battery charged in parallel does not have a lithium battery protection board, the charging voltage must be limited to 4.2V, and a 5V charger cannot be used. 4.) After the lithium batteries are connected in parallel, there will be a charging protection chip to charge and protect the lithium batteries.