4 ms·
1 gallon of regular gasoline is 33kWh and a gallon weighs 6lbs. For a 33kWh battery pack comprised of 18650 Samsung 35E cells, you’re probably looking at around
by jsjohnst 4y ago
1 gallon of regular gasoline is 33kWh and a gallon weighs 6lbs. For a 33kWh battery pack comprised of 18650 Samsung 35E cells, you’re probably looking at around 300lbs for just the cells alone.
Irregardless, it doesn’t matter because an electric motor will be far more efficient using the energy stored than a fueled engine (be it gas turbine or ICE). In automobiles for example, 80% of the energy from the gasoline is wasted.
- AdrianB1 4y agoThe efficiency of gasoline and Diesel engines is a lot better, over 30% and even over 40% for Diesel. I think the best gasoline engines get close to 40%.
- jsjohnst 4y agoSure, the best diesel engines get 40-45% and some gasoline engines approach 40%, but that is definitely not the norm. The average is 20% for gasoline (hence my prior figure) and 30% for diesel, which is a far cry from the average electric motor’s efficiency of around 90% in automobiles.
- darksaints 4y agoThose are all roughly true numbers but you forgot charge efficiency: energy extracted out of battery / energy input into battery. That's also around 90% (assuming higher voltage charging, not 120v AC which would be closer to 60%). That would put total efficiency of battery electric closer to 80%.
- pmayrgundter 4y agoBut not necessarily more efficient at thrust.. a turbine is mixing fuel with oxygen from the env to both spin the turbine but also vents the exhaust and gets thrust that way. So it doesn't carry smth like 3/4 of its reaction mass. I know that turbofans duct in most of their flow, so not sure how this nets out on a large-scale device.