Hello
I am looking into making myself a powerbank based on 18650 cells I'm planning to salvage from old laptops. But I want it to be kind of a group bank meaning it would be able to charge 10 devices simultaneously. During the research I did yesterday, I figured out some things. Note that these are my understandings, if there are inaccuracies, please correct me. Also I am a complete newbie to electronics so please be patient
Now, things I've concluded:
1) I need 10 amps to provide the 10 ports with it's maximum power output of 0.9 amps because amperage gets divided between outputs while voltage remains the same.
2) I need to run the cells in series/parallel to achieve 7.4 volts (to be reduced to 5) and high mAh capacity.
These conclusions are based on http://batteryuniversity.com/learn/article/serial_and_parallel_battery_configurations
I would like to implement a RGB LED array to indicate current storage of a so-called section (marked with gray on image). So when one section is full, it's LED would be green and eventually change to red as the cells empty (or section dies). I found some things called rheostats, but I don't understand how they work alone and in combination with LEDs.
I'd also like the powerbank to have passtrough charging capability.
I've left the scheme incomplete since I do not know how to show some things. (USB connections (series/parallel), rheostats and LEDs, passtrough charging.
Any help is greatly appreciated!
TheCreepySheep
I am looking into making myself a powerbank based on 18650 cells I'm planning to salvage from old laptops. But I want it to be kind of a group bank meaning it would be able to charge 10 devices simultaneously. During the research I did yesterday, I figured out some things. Note that these are my understandings, if there are inaccuracies, please correct me. Also I am a complete newbie to electronics so please be patient
Now, things I've concluded:
1) I need 10 amps to provide the 10 ports with it's maximum power output of 0.9 amps because amperage gets divided between outputs while voltage remains the same.
2) I need to run the cells in series/parallel to achieve 7.4 volts (to be reduced to 5) and high mAh capacity.
These conclusions are based on http://batteryuniversity.com/learn/article/serial_and_parallel_battery_configurations
I would like to implement a RGB LED array to indicate current storage of a so-called section (marked with gray on image). So when one section is full, it's LED would be green and eventually change to red as the cells empty (or section dies). I found some things called rheostats, but I don't understand how they work alone and in combination with LEDs.
I'd also like the powerbank to have passtrough charging capability.
I've left the scheme incomplete since I do not know how to show some things. (USB connections (series/parallel), rheostats and LEDs, passtrough charging.
Any help is greatly appreciated!
TheCreepySheep