I have made a video on Youtube about the prototype of a high-quality battery bank that I have developed and tested over more than 6 months now. It is Lithium-ion battery-based and the current prototype uses a 4s combination.
I have built it to output dual 12 volts and each output can deliver up to 3 amperes of current.
I also have a few external modules which can further step down the voltage to 9.0 volts, 8.4 volts, 5.0 volts, etc.
Kindly review the same and send your valuable comments to improve the same. Below is the video link.