I am designing a system to charge a single cell lithium battery. It requires pass-through, path-selection, over and under voltage protection. The bottom line is this system needs to power a device while unplugged, and continue powering it while it is plugged in charging the battery. This is for a research project, not any sort of commercializable product. It also has an expected lifetime of only about 3 weeks, so battery degradation isn't a huge deal. After trying numerous boards out from various suppliers, and even attempting to make our own we found one that almost works like we need it.
The problem is the pass-through current is too low, and the charging current is too low. Ideally we need something that works like a laptop where it continues to be powered whether it is charging or not. Right now it can output 1A maximum. We would like to double that to 2A if possible (or more up to 3A even).
With an approaching deadline is there a board available online that we are missing that does all this, or is there a modification/new design we can use to make this work?
Thanks for you help in advance!