Part of the week: LT8554 and on the art of cell balancing

This week’s part of the week is a Linear Technology’s LT8584. The part is a DC-DC converter that is designed for a very specific purpose- active balancing of battery cells. In a typical long battery string, no matter how tightly matched initially, there will always be cells that end up with a bit more or a bit less charge. Over time these imbalances start affecting what the battery can deliver, as one week cell may trigger undervoltage limit for example and shut the whole pack down despite other cells being perfectly happy. Continue reading

Upgrading an electric lawn mower to lithium batteries

Part 1- getting the platform

This all started when we bought a house and it came with a bit of grass. And grass wanted to grow and had to be cut. Initially I paid a lawn service to come and cut it, but they kept cutting bits I did not want them to. So I looked at the annual amount I was paying them and decided that would be my budget for a mower. Being an electrical guy, I very much dislike all things gas powered, stinky and noisy. So the absolute requirement was for the mower to be electric.  I looked around a bit, and my choices seemed to be a bunch of no-name large box store mowers running Lead Acid batteries or corded, a few exotic European market-only Lithium powered mowers or making my own. I picked neither  Continue reading