I'm absolute beginner in electrical engineering and I need help in building a powerbank using three different batteries with different characteristics.
I have a sudden passion to implement this project because it's very interesting to me and I want to create my own powerbank and don't buy a new one branded by Xiaomi etc.
What I have now is 3 batteries:
- Biggest one (black color) it is a used battery. I came out of a Asus Nexus 7 2012 and its capacity decreased by big amount of cycles of charging/discharging. It has strange
black black yellow white red redwire and I don't know exactly where is + and - and I have no tool with help which I can detect it. How can I determine its conbections? Its capacity is 4325mAh, 3.7V and 16Wh (as it described on photo below.)
- Middle size one (silver color.) It is a new battery (about 5 charges/discharges) and it was used in a case-powerbank for my iPhone (it accidentally crashed and I've extracted the battery.) Its capacity is 5000mAh, 3.7V and unknown Wh (I'll update my question once I get it.)
- Small size one (silver color.) It is a new battery (about 10 charges/discharges) and it was used in powerbank for my iPhone (it accidentally crashed and I have extracted the battery.) Its capacity is 2020mAh, 3.7V and 7.68Wh or 7.88Wh
I want to unite them all sequentially so all capacities will be added (4325+5000+2020.)
Only one my requirement is I need 1 usb port for this powerbank and it should be 1 ampere (non high voltage) because it's completely enough for my iPhone 6s.
I'm going to print a case on 3d printer from plastic.
Is it possible?
Can you give advice me, please, what I have to buy and what I need to learn and may be some blueprint and some
voltage balance board(correct me if I'm wrong) and some other boards and where I can buy them (quality board, please.)