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> The planes are zero emission aircraft running on lithium ion batteries How heavy is that battery pack??

by ythn 8y ago

derefr 8y ago
Why is it that we use heavy solid/liquid electrolytes, anyway? It seems that gaseous electrolytes are possible; in an environment where volume doesn’t matter nearly as much as weight, wouldn’t a battery built on such an electrolyte be an obvious choice?
- ggg9990 8y ago
  The volume would be insanely high. Like blimp sized.
- haroldl 8y ago
  Not there yet, but yes, people are thinking about this: https://en.wikipedia.org/wiki/Lithium%E2%80%93air_battery https://en.wikipedia.org/wiki/Lithium%E2%80%93air_battery
- dredmorbius 8y ago
  Metal-air batteries gain mass as they discharge. Non-ideal for aviation.
rainbowmverse 8y ago
https://en.wikipedia.org/wiki/Pipistrel_Alpha_Trainer#Alpha_Electro https://en.wikipedia.org/wiki/Pipistrel_Alpha_Trainer#Alpha_... >> Pipistrel introduced an electric version called the Alpha Electro in 2015 at a price of 69,000 euros,[3] with technology from the Pipistrel WATTsUP proof of concept design, for short training. It has energy for one flight hour plus reserves, and can recharge in 45 minutes or have its batteries replaced in 5 minutes.[4] Instead of 78 lb (35.5 kg) of fuel, it has 277 pounds (126 kg) of LiPo cells, however the water cooled electric motor weighs 11 kg;[5] much less than the gasoline engine. It has a useful load of 380 lb, whereas a Cessna 152 has between 350-480 lb useful load.[6][7]
Shivatron 8y ago
There are two packs, one forward and one aft, each 53 kg (~117 lbs) for a total of 106 kg (~234 lbs). For comparison, the same weight of avgas (39 gal) will fly a Cessna 172 for just under 4 hours with reserves (assuming 9 gph), compared to the the Alpha’s 60 minutes.
- hengheng 8y ago
  What decade is the 172's engine from? I keep hearing that all GA planes are basically vintage cars.
  - avs733 8y ago
    I'm far from an expert on this but my understanding is similar. I think there are several technical and market reasons for this. First is the simple cost of developing and certifying a new general aviation engine. That cost must be covered by sales in an already cost difficult market. The second part is technical...plane engines are used very differently than car engines. They are not purely steady state but they are typically used in a near steady state way. This makes improvements such as fuel injection less additive beneficial. Ad in that most of the uses of the engines are non-commercial and non-life critical and you have a logic - why would I spend tones more to gain a few points of efficiency on something I use for fun that already costs me an arm and a leg that works. Its the same reason you don't see the most fuel efficient innovations start in sports cars. example: look at the Lycoming O-360 and the list of planes it is used in. https://en.wikipedia.org/wiki/Lycoming_O-360 https://en.wikipedia.org/wiki/Lycoming_O-360
  - deleted 8y ago
    [deleted]
  - jandrese 8y ago
    Typically they are equipped with either a Continental O-300 series engine from the 40s, or a more modern Lycoming O-320/360 from the 50s. They hark back to an era of magnetos and manually adjusting the fuel mixture. On the plus side they're so mechanically and electrically simple that there's very little to break. On the downside they're pretty inefficient and carburetor icing is still an issue. Also, they need leaded gas still. https://en.wikipedia.org/wiki/Continental_O-300 https://en.wikipedia.org/wiki/Continental_O-300 https://en.wikipedia.org/wiki/Lycoming_O-320 https://en.wikipedia.org/wiki/Lycoming_O-320 https://en.wikipedia.org/wiki/Lycoming_O-360 https://en.wikipedia.org/wiki/Lycoming_O-360 I'm not kidding about the efficiency either. The Lycosaur O-360 is a 5.9L engine that produces at best 225hp. You can get 245hp out of a 2L Ecoboost in an economy car today. This isn't an apples-to-apples comparison, but it gives you a sense of how far engines have come since the 50s. A Cessna 172 retrofitted with a modern engine could probably get more than a 50% increase in range, and also cabin heat.
deleted 8y ago
[deleted]

> The planes are zero emission aircraft running on lithium ion batteries How heavy is that battery pack??

by ythn 8y ago

> The planes are zero emission aircraft running on lithium ion batteries How heavy is that battery pack??

Why is it that we use heavy solid/liquid electrolytes, anyway? It seems that gaseous electrolytes are possible; in an environment where volume doesn’t matter nearly as much as weight, wouldn’t a battery built on such an electrolyte be an obvious choice?

ggg9990 8y ago
The volume would be insanely high. Like blimp sized.
haroldl 8y ago
Not there yet, but yes, people are thinking about this: https://en.wikipedia.org/wiki/Lithium%E2%80%93air_battery https://en.wikipedia.org/wiki/Lithium%E2%80%93air_battery
dredmorbius 8y ago
Metal-air batteries gain mass as they discharge. Non-ideal for aviation.

rainbowmverse 8y ago

https://en.wikipedia.org/wiki/Pipistrel_Alpha_Trainer#Alpha_Electro https://en.wikipedia.org/wiki/Pipistrel_Alpha_Trainer#Alpha_... >> Pipistrel introduced an electric version called the Alpha Electro in 2015 at a price of 69,000 euros,[3] with technology from the Pipistrel WATTsUP proof of concept design, for short training. It has energy for one flight hour plus reserves, and can recharge in 45 minutes or have its batteries replaced in 5 minutes.[4] Instead of 78 lb (35.5 kg) of fuel, it has 277 pounds (126 kg) of LiPo cells, however the water cooled electric motor weighs 11 kg;[5] much less than the gasoline engine. It has a useful load of 380 lb, whereas a Cessna 152 has between 350-480 lb useful load.[6][7]

Shivatron 8y ago

There are two packs, one forward and one aft, each 53 kg (~117 lbs) for a total of 106 kg (~234 lbs). For comparison, the same weight of avgas (39 gal) will fly a Cessna 172 for just under 4 hours with reserves (assuming 9 gph), compared to the the Alpha’s 60 minutes.

hengheng 8y ago
What decade is the 172's engine from? I keep hearing that all GA planes are basically vintage cars.
- avs733 8y ago
  I'm far from an expert on this but my understanding is similar. I think there are several technical and market reasons for this. First is the simple cost of developing and certifying a new general aviation engine. That cost must be covered by sales in an already cost difficult market. The second part is technical...plane engines are used very differently than car engines. They are not purely steady state but they are typically used in a near steady state way. This makes improvements such as fuel injection less additive beneficial. Ad in that most of the uses of the engines are non-commercial and non-life critical and you have a logic - why would I spend tones more to gain a few points of efficiency on something I use for fun that already costs me an arm and a leg that works. Its the same reason you don't see the most fuel efficient innovations start in sports cars. example: look at the Lycoming O-360 and the list of planes it is used in. https://en.wikipedia.org/wiki/Lycoming_O-360 https://en.wikipedia.org/wiki/Lycoming_O-360
- deleted 8y ago
  [deleted]
- jandrese 8y ago
  Typically they are equipped with either a Continental O-300 series engine from the 40s, or a more modern Lycoming O-320/360 from the 50s. They hark back to an era of magnetos and manually adjusting the fuel mixture. On the plus side they're so mechanically and electrically simple that there's very little to break. On the downside they're pretty inefficient and carburetor icing is still an issue. Also, they need leaded gas still. https://en.wikipedia.org/wiki/Continental_O-300 https://en.wikipedia.org/wiki/Continental_O-300 https://en.wikipedia.org/wiki/Lycoming_O-320 https://en.wikipedia.org/wiki/Lycoming_O-320 https://en.wikipedia.org/wiki/Lycoming_O-360 https://en.wikipedia.org/wiki/Lycoming_O-360 I'm not kidding about the efficiency either. The Lycosaur O-360 is a 5.9L engine that produces at best 225hp. You can get 245hp out of a 2L Ecoboost in an economy car today. This isn't an apples-to-apples comparison, but it gives you a sense of how far engines have come since the 50s. A Cessna 172 retrofitted with a modern engine could probably get more than a 50% increase in range, and also cabin heat.

deleted 8y ago

[deleted]