Many of us will own a lithium-ion power pack or two, usually a brick containing a few 18650 cylindrical cells and a 5 V converter for USB charging a cellphone. They’re an extremely useful item to have in your carry-around, for a bit of extra battery life when your day’s Hackaday reading has provided a worthy use for most of your charge. These pack are though by their very nature inflexible, no matter how many cells you own, the pack will only ever contain the number with which it was shipped. Worse, when those cells are discharged or even reach the end of their lives, they can’t be swapped for fresh ones. [Isaacporras] has a solution for these problems which he calls the Power Stacker, a modular battery pack system.
At its heart is the Maxim MAX8903 lithium-ion charge controller chip, of which one is provided for each cell. A single cell and MAX8903 with a DC to DC converter for 5 V output makes for the simplest configuration, and he has a backplane allowing multiple boards to be connected and sharing the same charge and output buses.
An infinitely configurable battery bank sounds great. It’s looking for crowdfunding backing, and for that it has an explanatory video which you can see below. Meanwhile if you’d like to try for yourself you can find the necessary files on the hackaday.io page linked above.
I think my sarcasm detector is on the fritz
I’m already working on version 2, which contains a charge controller and isolated ground on each cell so you can connect them in series no problem. I’m just showing version 1 because it is a better demonstration of the configurable concept. Don’t worry, I’m working on it.
I’d love to have something like this but sort of industrialized. I have a lot of varying capacities of LiFePo’s as well as a bunch of random LIIon’s (none of which are matched) that I want to turn into a PowerWall-ish backup system. An architecture like this could be employed regardless of the condition (or type) of any individual cel.
I agree! Why not pull a few cells off your power wall and use them to charge your phone on the go! Hopefully I have the opportunity to fully develop and manufacture this concept!
Hackaday… you been tracking our browsing activities? lately your articles have been disturbingly spot on with what ive been researching.. been a reader since before 2007 and the change over. jus checking making sure the evil bots havent taken over…. nice article. spot. on.
I have this same feeling, and have been a reader even earlier than you! Google searches, and Youtube videos suddenly appear here as if I’ve given a tip to the writers.
So, the developing Conspiracy Theory is; HackADay is in cahoots with Google, spying on our web searches and smart phone eavesdropping for inspiration.
I could buy into that!
B^)
I dismantled a few battery packs from dead laptops, and now I have around 2 dozen 18650 Li-ion cells of varying capacities. I have little idea what to do with them, besides using them in flashlights and as a 1-cell power bank–I don’t know how to safely connect 2 or more cells in series/parallel in order to make higher voltage (or capacity) packs. This project seems to be a step in the right direction.
Thanks! My design uses a charge controller and isolated ground on each cell, which seems like a lot, but it removes the need for cell balancing.