This customer already had a line of products and wanted to add a battery pack to introduce a mobile edge. They were adamant about reliability and safety, rightfully so because lithium-Ion batteries can be quite dangerous if the circuitry does not have the necessary safety features.
Working with our battery supplier, we designed protection circuitry into the pack to safeguard the bare cells. We brutally tested multiple samples until we arrived at a final working solution. Then, we set up a production and test plan with the manufacturer.
The bare cells were now protected but we wanted to implement all possible safety circuits. So we added over/under voltage, over/under temperature and over current protection to the power supply circuitry for charging the pack. We then optimized the charging profile for temperature inside the case and the current capabilities of the pack.
Along with a rock-solid charger design, we also added a boost voltage converter so the output voltage was consistent, whether running off a full pack, an almost-empty pack or wall power. There is also an interface circuit for user feedback such as battery capacity, charging status, failure to properly charge and output status.
After completing the final unit test, we worked with the customer's mechanical design team to integrate the working prototype into their hardware. We also delivered all design files and test data so they could move to production.
