DIY Portable Power Bank From an Old MacBook Battery

Parts needed

1x MacBook battery cells, it's also possible to use another type of battery.

1x DC-DC converter USB module (with charging) - from eBay ~5-7$.

Electrical wires for making connections

Material list:

- Solder wire (Tin)

- Flux

Tools needed:

- Soldering Iron

- Pliers

- Wire stripper

- Multi-meter

Check the Lithium cells. It's preferable to choose only the "live" cells that have at least 3+ volts stored. Avoid using cells that are over discharged or that have 0 volts as they may burst when are being recharged.

Solder all tested cells in parallel. Take care not to overheat the batteries as they are sensible to heat excess.

Connect the battery terminals to the DC-DC converter module, following it's provided indications on activating it. After it starts connect USB power to charge the cells.

All the procedure in a video.