During the testing phase of Solar Miner III the car was operational long before we had a solar array attached. However, to run repeated tests we needed some way of charging the batteries without using solar power. I took up the design and started by evaluating several different charge control ICs.
Partially due to its availability in DIP packaging I settled on a TI IC to run the setup. What I didn't realize was how difficult it would be to design a switch-mode converter with no prior experience. The charger needed to charge either 1 or 3 cell lithium modules at up to 10A. Thus the maximum power output would be greater than 100W, much outside the range of simple linear regulators.
After studying switch-mode design for some time, and extensive SPICE simulation, I arrived at a design that functioned, and was reliable enough to last for the life cycle of Solar Miner III.
