What is the right way to connect the cells of this battery pack, and tips on making a power bank? Answered
I have a few questions about connecting Battery cells, and making a DIY Power Bank.
And I'd like to hear your opinion on it.
I have 12x Ni-Mh 1.2v 3000mAh AA betteries laying around. They are brand new and I thought of using them to make a Power Bank.
Since most phones use 5v for charging I wanted to connect 4 cells in series giving me 5v and 3 of these packs in parallel for an end result of a single 5v 9000mAh Battery Pack.
But when I started to connect them I realized that there are 2 ways it can be done, and I am not sure which is the right one.
Is there any difference at all?
I will add a picture below, as it says more than thousand words.
Furthermore I would like to ask for your opinion on how to proceed making a functional power bank. Just wiring the cells straight to an Usb port doesn't seem like a smart idea.
What would I need to make sure it is safe for the devices it charges?
And how could I make the Power Bank rechargeable via Usb?
Thanks in advance.