But, this is so different. A car runs on 1/10 to 1/5 of the cruise power of a plane (especially the “feature-minimised” cars which are most of the electric car scene) and a 9hr charge is fine for a car (at night) but useless for a plane, in this application scenario.
Peter wrote:
I think swapping a 500kg battery pack is going to be a whole load of fun
E.g. Pipistrel split the battery of their electric plane into modules. I don’t know how heavy is one of those modules, I think a single person can replace the whole battery one module at a time. A half a tonne battery would of course require a lot of modules to be kind to your back.
aart wrote:
My cars are charged through a normal single-phase 220V socket, eating 8A, charged in 9 hours for a 160 km range.
Assuming your car’s average speed is 50 Km/hr, I think that means your average power underway is something like 7 HP. That extrapolates in a fairly obvious way to 250 HP, which is roughly the average power for an aerobatic aircraft doing its thing. Shortening the aircraft’s endurance to 45 minutes, it would take over a week to recharge between flights.
Mark_1 wrote:
There appears to be 14 battery trays of about 10-12 litres volume, which would suggest about 80-90 KWh and around 500kg with current technology. Add on inverters and power electronics etc.
I calculate that as being enough for a 20 minute aerobatic flight, carrying the weight equivalent of 183 gallons of 100LL in batteries, plus the power electronics, cables etc. Luckily the motor itself is lighter than the Lycoming!
aart wrote:
Also nice to know that if you crash, you don’t have a load of fuel crashing alongside you.
Have you ever seen a lithium fire? I don’t know what they’re using, but Li-ion cells don’t tolerate physical damage. Not that a wet wing full of avgas is something safe in a crash.
vic wrote:
Three phase power supply to private houses should be pretty standard by now as the power station would not be very happy to have a very unbalanced load between the phases when only one phase is used
Obvious solution is to distribute the three phases among the houses in the area (and it gives you control over the distribution).
That is what happens currently, in various ways, and maybe one day 3 phase electricity meters will be commonly installed – in anticipation of electric car charging. I had one installed in what is now my ex wife’s house, for a different reason. Today’s cost would be about £5k, for a ~30m overhead wire.
But it doesn’t address the provision of say 150kW to a remote airfield.
Martin wrote:
Have you ever seen a lithium fire? I don’t know what they’re using, but Li-ion cells don’t tolerate physical damage. Not that a wet wing full of avgas is something safe in a crash.
Not all lithium batteries present a fire hazard. LiFePO4 and Li2TiO3 ones are quite safe in that respect. They are somewhat inferior in energy density, but more tolerant of extremely rapid discharge and recharge, and have a longer lifespan.
Peter wrote:
maybe one day 3 phase electricity meters will be commonly installed
I’m not in building construction, but I would say the trend has been the opposite for years around here. In the past, three phase supply was common. You would commonly find three phase sockets, even in recreational houses. They were used to power cement mixers, table saws, etc. I think I even saw a three phase lawn mower. But I don’t think the new houses in and around cities commonly have it (unless you requested it). These days, I don’t think most people have use for it. Judging by what I saw, which is just anecdotal evidence. I’m not saying this can’t change, just that we already were there.
Peter wrote:
Today’s cost would be about £5k, for a ~30m overhead wire.
Around here, everything except higher voltage distribution is underground. Even in small, sleepy villages (on some old houses that were not renovated in decades, you can still see the remnants of the old overhead distribution). Which would make it even more expensive. Maybe they provisioned for it, it’s better to dig just once (both my parents and I always had three phase in our houses so I never had to investigate). From what I heard, plenty of apartments can get three phases and there are sometimes even provisions for it so it’s easy (e.g. there might be three phase cabling right up to the kitchen even though the stove used gas, just in case you wanted to change to three phase electric one down the road).
As you wrote, this isn’t really relevant in the case of an airfield. I wouldn’t be surprised if they had three phase already, but who knows what the cabling can actually deliver.
@Ultranomad I’m somehow not used to using Li-ion as an umbrella term. When talking batteries and someone says Li-ion, I understand it as the chemistry that was typically used in consumer electronics, LiCoO2. Because that’s the term consumers know.
Well, 3 phase has been the standard for over 100 years, but that isn’t the Q here.
