eAcademy with Ludwig Retzbach

65 participants, some of whom had traveled quite a distance, gathered one Friday at the Trendhotel Regensdorf-Watt after registering in the preceding weeks and paying a participation fee of CHF 20.–.

The seminar was divided into two parts. First, the various battery types were explained, including their chemistry during charging and discharging, their construction and operation, and a performance comparison of their energy density per unit of weight. Particularly interesting were the explanations regarding LiPo batteries, specifically their high C-rates for charging and discharging and the impact on their lifespan and cycle count. On this occasion, the speaker also put the “C-rate fetish” into perspective by pointing out that high C-rates mean more weight and are, in most cases, not necessary at all. Ludwig Retzbach also provided interesting insights into potential future battery developments. After all the participants’ questions on this topic had been thoroughly answered, there was a break during which participants could help themselves to mineral water, which was included in the registration fee.

The second part of the presentation focused on charging techniques, the potential hazards of LiPo batteries, and the condition in which they should always be disposed of. Ludwig Retzbach went on to explain why these batteries should always be balanced whenever possible and how individual cells can become deeply discharged. In this context, Rolf Jäger, owner of eflight GmbH, showed a video demonstrating the program he developed for testing LiPo packs using a current sink. The behavior of the individual cells under load could be observed both graphically and in numerical terms. This program is used in practice to verify manufacturer specifications and ensure that what’s on the label matches what’s inside. After all other topics and questions regarding LiPo batteries had been addressed, Rolf Jäger closed the event at 10:15 p.m. to a round of applause for Ludwig Retzbach. After a very interesting yet enjoyable evening—Ludwig Retzbach never missed an opportunity to spice up the dry subject matter with a fitting witticism or lighthearted remark—the satisfied participants headed home, knowing they had learned a great deal. Anyone interested in reading more about this topic can find publications by Ludwig Retzbach at www.eflight.ch.