another parallel question for 18560's

[johnnym]

The info found about 18650 battery banks is immense and I am sorry if this question has been answered. I hope someone can answer this question.

I have 4 good 18650 batteries from the same laptop. They were charged individually to 4.2v. I let them sit for a month. 3 batteries now read 4.17 and one reads 4.16. If I connect them in parallel is it really dangerous? Do I need a bms for something this small?

They will be used with the tp4056 and 5v boost converter for a portable power bank.

 

[eee291]

Connecting cells with such a little voltage difference isn't gonna be a problem at all.

I connected two HG2 Cells with a 0.2V Delta without any significant inrush current.

 

[Hillhater]

Single cells in parallel do not need a BMS...
.....assuming you have a correct charger for them.