Energy costs for a battery charge

Sure, the cost in francs of the electricity used for our hobby is negligible. Still, I wanted to get to the bottom of it. So I got an energy meter to measure the kilowatt-hours (kWh) consumed from the outlet. I charge my batteries using the Schulze isl6-636+ charger. Today’s standard chargers operate on 12 V DC. The charger is therefore plugged into a power supply unit that steps down 230 volts AC to 12 V DC. Of course, the charger can also be powered by a 12-V battery, but this isn’t practical for larger batteries. So far, so good—and now for the interesting part. I’m now connecting the energy meter in front of the power supply, that is, between

the 230-V outlet and the power supply. I’m interested in the actual power consumption—the amount I actually pay for on my electricity bill (see setup below). I use the two LiPo batteries to power an electric motor in a 2-meter model weighing 5,000 g. After 8 to 10 minutes of motor runtime, an average of 4,000 mAh has been consumed. During flight, LiPo batteries should be discharged to a maximum of 80% of their capacity. The 10S4P batteries from Thunder Power that I use have a capacity of 5,300 mAh.

To fully recharge a battery pack in this setup, an average of 0.24 kWh of electricity is drawn from a 230-volt outlet. Assuming an electricity price of 15 Rp./kWh, this comes to 3.6 Rappen per battery charge. For 100 flights, that comes to about 3 francs and 60 rappen.

As I suspected at the beginning, the electricity costs are very low. Nevertheless, electric flight is a costly endeavor, especially with larger models.

However, one shouldn’t just consider the pure acquisition costs. With electric flight, the risk of experiencing an engine failure in flight is completely eliminated. An unplanned off-field landing can also be quite costly. In addition, maintenance costs are significantly lower.

Ultimately, the power system must also suit your personal preferences.

Wishing you all the best with your electric models,

Michel Hauser