All Electric Proof of concept Prototype

[spenaroo]

yeah,

I think any serious change will come from re-imagined production methods.

we started with rag and tube, and went to composites.

frames to monocoque.

the next method will need to incorporate batteries into the structure, instead of thinking of it as a fuel cell to bolt in.

interesting to think of weight and balance, your take off and landing will be the same.

[FlyBoy1960]

You are lighter when you land with flat batteries (in theory)

[facthunter]

That's perspiration. Not inspiration. Nev

[kasper]

9 minutes ago, FlyBoy1960 said:

You are lighter when you land with flat batteries (in theory)

well IF e=mc^2 is perfectly applicable my 14.5khw batteries will be about 580 nanograms lighter ... that is 580 time a nanogram

 

a nanogram is 1 thousand millionth of a gram ... that is 1 / 1,000,000,000,000 of a kilogram ...

 

Lets just say they weigh the same for all practical purposes. 

[onetrack]

Ralph Sarichs innovation company, Cape Bouvard Technologies, is trying to progress a "structural battery", but I'm not sure how far they've advanced, or how many millions they've poured into it. They've been onto it for at least 10 yrs.

 

http://www.capebouvardtechnologies.com.au/tech

 

I get the distinct impression, that to get a major advance in battery efficiency, along with lighter weight, requires a huge amount of money, and a very large research team.

 

As a result, it is the universities that are being funded by backers with deep pockets, that are "producing the goods", when it comes to major advances in battery design.

 

Look at Elon Musk, one of the richest men on the planet, with the ability to pour mega-billions into research, and the Tesla 4680 battery is the best he and his teams can come up with.

 

 

Edited July 1, 2022 by onetrack

[Flightrite]

The Oil CO’s are happy that the EP boffins are floundering with battery technology, I think the Oil CO’s are safe for a very long time😂

[Ian]

55 minutes ago, onetrack said:

Cape Bouvard Technologies, is trying to progress a "structural battery",

It doesn't really matter whether a current battery is structural or not, they're just heavy.  Battery powered electric airplanes might be OK for short duration training flights or for people who want to tool around on the weekend flying circuits. They're less attractive as a form of A-B transport.

Batteries are heavy and the rate of improvement hasn't changed much in the last decade, cheaper yes, lighter no. One possibility for a battery would be a something like a lithium-air battery however there are significant issues to overcome prior to this becoming a thing. These issues may prove to be insurmountable, just look at fusion, conceptually easy in practice very difficult.

You might want to consider aluminium-air batteries however they're non rechargeable which mightn't fit with the attractive vision of just plugging the plane in for a few hours before flying off, and they're not cheap. 

Another option for aircraft might be to resurrect the liquid salt reactor concept but while this is technically feasible in large transport airplanes I can't see many people waving flags to have flying reactors especially when we can't even get them built as a replacement for coal reactors.

 

As an aside the French have the greatest percentage of nuclear power, are a net electrical energy exporter, have some of the lowest greenhouse gas emissions in Europe and power which costs about half the cost of Germany. They've been demonstrating how to operating their reactors in a dispatchable manner even though they weren't designed for this role allowing them to dovetail nicely with solar and wind generation. 

 

 

 

[Bernie]

17 hours ago, kasper said:

Hmmm  I'm using LIFEPO4 chemistry which is not the lightest lithium battery (but quite a bit less flammable) and I have a 14.5kwh battery setup for the Sapphire that with the BMS weighs in at 88kg before I start slotting it around the airframe. 

Prorata for the capacity difference my setup is exactly the same kg/kwh as Ducati get ... maybe I am on the right track. 

 

Admitted my 88kg does not include the battery boxes I've built into the new wing and behind the seat but they are all vac bagged carbon and very light so my system is stacking up so far.

 

My concern with the Eflyer is that they are going to be using a lot of power even in economical cruise to stay up there so they will need lots of battery ... and these things are still heavy per kwh. 

 

Just think

- Eflyer has 110kw motor,

- guessing it uses 30-40kw to fly at endurance

- they claim 3hrs endurance

- they need around 90-120kwh of battery

- LIFEPO4 systems weigh 6kw/kwh

This would imply a battery pack of around 540-720kg

That is not believable.

 

Even if using really good (very flammable) lithium batteries its not much better - the current Tesla 100kwh lithium pack comes in at 625kg.

 

I just cannot see how they can possibly get the performance they claim out of the available technology.

Did you make your own BMS or came with your battery pack?

Bernie.

[Ian]

17 hours ago, kasper said:

 

Lets just say they weigh the same for all practical purposes. 

The easiest way to make this lighter would be to go on a diet. You're pushing the boundaries of the technologies, it sounds interesting good luck with it. Does your BMS monitor cell termperature?

If you get your estimated 2 hours with your setup how long would a charge take a between flights?

[kasper]

1 hour ago, Ian said:

The easiest way to make this lighter would be to go on a diet. You're pushing the boundaries of the technologies, it sounds interesting good luck with it. Does your BMS monitor cell termperature?

If you get your estimated 2 hours with your setup how long would a charge take a between flights?

Im a middle aged man who has the same trouser size as I did at 21.  Losing weight is not in my mindset I’m happy with not gaining more.  
 

my bms is off the shelf and has 2 temp sensors …. I know that is not enough when I’m splitting the pack into three areas in the airframe but the draw on the pack is well within the specs for the batteries so I’m considering this area of management. 

 

as for recharge it’s still an open item.   The charger is NOT going in the plane and I’m still working on options.  The hangar/shed has 6kw of solar and 25kwh of agm batteries so the slow recharge from that alone will sit at around 5-6hrs to 80% as I can’t push too much current around without losing efficiency or getting heat issues on recharge.
 

not sure what I’ll do if it works and I want to go somewhere.  Can’t really pull over to a Tesla supercharger 🤣

 

but this is not intended to be a go somewhere plane.  It’s my let’s see if I can do this plane.  I have other planes with IC engines to go somewhere in or fly when the sapphire is on recharge.  

[kgwilson]

Battery technology continues to improve and CATL's new QiLin battery has an energy density of 255 watts per kg at the pack (not cell) level and has a new disruptive water cooling system which increases heat transfer 400% as well and can be charged from 0 to 80% in 10 minutes. This will provide medium sized cars with more than 1000 km of real world range. CATL is planning to have the batteries in mass production by the end of Q1 2023.

 

So an 18 kWH battery will weigh 70 KG (the same as 97 litres of fuel). Add the difference between an ICE engine and the electric motor (which weighs about 20KG) plus the fast charger and you will have an excellent training platform.

 

The Pipistrel Alpha Electro has a 21.5 kWH battery and provides 1 hour of circuit training with a 30 minute reserve recuperating 13% of its energy during approach using 5 year old battery technology. Textron (Cessna, Beech Lycoming) recently bought Pipistrel so they see a very good future in electric aircraft.

[Ian]

The energy content of 97 litres of fuel ~= 850 kW/h even at 30% efficiency that about 255kW/h at the prop. And the bonus is that as you use fuel you get lighter.

 

A nice BMS might be this one. https://www.ennoid.me/  It's open source so if you don't want to buy it you might be able to save yourself a few shekels by building it. It has individual temperature sensors and achieves balanced charging. It also is scalable using master/slave model with the main controller controlling a number of smaller pack based units.

 

 

[kasper]

The advantage - sort of - with an battery electric system is that it’s pretty flexible as to what throws electricity at the motive system.  
 

if a better batter comes along with better recharge and energy density it’s only part of the system that needs changing.  An expensive part but only part.  
 

if 10 min fast charge battery systems become available in a few years then it’s its a yes room of if it can be used to replace what I’ve already got.

 

if hydrogen PEM stacks and storage come down in price and overall weight they might be an option.   The trouble at the moment is a 6kw PEM stack while only 9kg is US$28k - not viable at this point.  
 

im happy fitting what’s pretty much off the shelf into what is really my aircraft design based on the sapphire. It’s not really a sapphire anymore when it’s got a different power train.  Different wing section.  Different wing area.  Different  wing platform and will have a different flight envelope and handling. 

[Flightrite]

Lot’s of “if’s” there😂

[kasper]

4 hours ago, Flightrite said:

Lot’s of “if’s” there😂

Yep.  That’s why it took until I could reasonably get an ultralight out to around 2 hours endurance for not a huge cost in power plant before I decided to have a go. 
 

all those ifs are on top of the minimum I set for what I need. If all those ifs were required then I’d not be even starting to plan.

 

My system will probably meet my needs.   Thanks all I need.