Hello,
I am designing a 3 to 6 cell 18650 battery charger and balancer for a 3D printer UPS application. Some printer uses 12V and others 24V, so on some boards the cells will be used in 2 packs of 3S in parallel and on some others 6S.
I thought to always charge them in the 2x3S configuration so I only need one charging circuitry for both cases, and then use mosfets to switch them to series mode when they need to be used in a 24V printer. I also thought to charge them all in parallel with one charger and then use mosfets to make the number of series cell that I want, to get rid of the cell balancer.
The problems that I face are:
- They seems to be no all-in-one ICs that does charging and balancing, and I don't know if I will be combining the two chips correctly, where can I find reference designs?
- I am not sure if my charging ideas above are going to work of make the packs explode, which is a slight problem, please give some feedback
- I found a charger for 6 cells that has a boost converter included,
http://www.linear.com/product/LTC4020, but that still makes 2 chips, is there really no all-in-one solution? Do you know the simplest chips for this application since I am still a newbie?
Thanks in advance for your help.