On Wednesday, August 18, 2021 at 7:41:28 AM UTC-7, Eric Greenwell wrote:
> On 8/18/2021 7:08 AM, Mark Mocho wrote:
> > The "other" thread about lithium batteries and design parameters had a suggestion of putting the batteries in the wings with some sort of cooling/heat dissipation method. Tesla uses a water jacket to cool their dense battery packs. Hmmm.. water and electricity. What could go wrong?
> >
> The wing mounted batteries do not necessarily need cooling. The Antares doesn't have it,
> for instance, but designs putting the batteries in an enclosure inside the wing might use
> a fan or ram air to move air through it. The box enclosed, fuselage mounted batteries
> (FES, ASG32EL, JS3RES, etc) all use fans and electricity - but no one seems puzzled over that.
>
> And, of course, using water cooling, air cooling, and electricity is absolutely essential
> for gasoline gliders - what could go wrong, eh?
> --
> Eric Greenwell - USA
> - "A Guide to Self-launching Sailplane Operation"
> https://sites.google.com/site/motorgliders/publications/download-the-guide-1

Cooling of lithium batteries is necessary because high temperatures (i.e. 100F) cause degradation of the batteries, and possibly accelerate failure mechanisms, whether the battery is in use or not. Tesla cools their battery packs even if the car is parked. So it doesn't matter where in the glider you mount the batteries. Internal temperatures of cars can reach 140F (https://www.clickorlando.com/news/2019/09/26/heres-how-hot-temperatures-can-get-in-your-car/#:~:text=A%20vehicle%20parked%20in%20the,cabin%20temperature%20of%20116%20degrees.&text=In%20a%20locked%20vehicle%2C%20a,air%20trapped%20inside%20a%20vehicle.)

Tom

On 8/18/2021 10:17 PM, 2G wrote:
> On Wednesday, August 18, 2021 at 7:41:28 AM UTC-7, Eric Greenwell wrote:
>> On 8/18/2021 7:08 AM, Mark Mocho wrote:
>>> The "other" thread about lithium batteries and design parameters had a suggestion of putting the batteries in the wings with some sort of cooling/heat dissipation method. Tesla uses a water jacket to cool their dense battery packs. Hmmm.. water and electricity. What could go wrong?
>>>
>> The wing mounted batteries do not necessarily need cooling. The Antares doesn't have it,
>> for instance, but designs putting the batteries in an enclosure inside the wing might use
>> a fan or ram air to move air through it. The box enclosed, fuselage mounted batteries
>> (FES, ASG32EL, JS3RES, etc) all use fans and electricity - but no one seems puzzled over that.
>>
>> And, of course, using water cooling, air cooling, and electricity is absolutely essential
>> for gasoline gliders - what could go wrong, eh?
>> --
>> Eric Greenwell - USA
>> - "A Guide to Self-launching Sailplane Operation"
>> https://sites.google.com/site/motorgliders/publications/download-the-guide-1
>
> Cooling of lithium batteries is necessary because high temperatures (i.e. 100F) cause degradation of the batteries, and possibly accelerate failure mechanisms, whether the battery is in use or not. Tesla cools their battery packs even if the car is parked. So it doesn't matter where in the glider you mount the batteries. Internal temperatures of cars can reach 140F (https://www.clickorlando.com/news/2019/09/26/heres-how-hot-temperatures-can-get-in-your-car/#:~:text=A%20vehicle%20parked%20in%20the,cabin%20temperature%20of%20116%20degrees.&text=In%20a%20locked%20vehicle%2C%20a,air%20trapped%20inside%20a%20vehicle.)
>
> Tom
>
The cooling I discussed was during discharge, which might be useful at high ambient
temperatures, but that is very dependent on the design details, especially the kWh of the
battery. You appear to be talking about storage temperatures, however, and everyone is
agreed cool temperatures are better for storage than high temperatures. Owners should
follow the storage procedures in the glider's operation manual to achieve the expected
battery lifetime.

Once again, you give us numbers from cars, even though they don't apply well to gliders.
The temperatures in a glider trailer will be much lower than a car interior because it is
painted white and does not have windows.

--
Eric Greenwell - USA
- "A Guide to Self-launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

It appears that all sense of humor and irony has left this group. 
....Unless it's about dick shaped airplanes and rockets.

Dan
5J

On 8/19/21 8:15 AM, Eric Greenwell wrote:
> On 8/18/2021 10:17 PM, 2G wrote:
>> On Wednesday, August 18, 2021 at 7:41:28 AM UTC-7, Eric Greenwell wrote:
>>> On 8/18/2021 7:08 AM, Mark Mocho wrote:
>>>> The "other" thread about lithium batteries and design parameters
>>>> had a suggestion of putting the batteries in the wings with some
>>>> sort of cooling/heat dissipation method. Tesla uses a water jacket
>>>> to cool their dense battery packs. Hmmm.. water and electricity.
>>>> What could go wrong?
>>>>
>>> The wing mounted batteries do not necessarily need cooling. The
>>> Antares doesn't have it,
>>> for instance, but designs putting the batteries in an enclosure
>>> inside the wing might use
>>> a fan or ram air to move air through it. The box enclosed, fuselage
>>> mounted batteries
>>> (FES, ASG32EL, JS3RES, etc) all use fans and electricity - but no
>>> one seems puzzled over that.
>>>
>>> And, of course, using water cooling, air cooling, and electricity is
>>> absolutely essential
>>> for gasoline gliders - what could go wrong, eh?
>>> --
>>> Eric Greenwell - USA
>>> - "A Guide to Self-launching Sailplane Operation"
>>> https://sites.google.com/site/motorgliders/publications/download-the-guide-1
>>>
>>
>> Cooling of lithium batteries is necessary because high temperatures
>> (i.e. 100F) cause degradation of the batteries, and possibly
>> accelerate failure mechanisms, whether the battery is in use or not.
>> Tesla cools their battery packs even if the car is parked. So it
>> doesn't matter where in the glider you mount the batteries. Internal
>> temperatures of cars can reach 140F
>> (https://www.clickorlando.com/news/2019/09/26/heres-how-hot-temperatures-can-get-in-your-car/#:~:text=A%20vehicle%20parked%20in%20the,cabin%20temperature%20of%20116%20degrees.&text=In%20a%20locked%20vehicle%2C%20a,air%20trapped%20inside%20a%20vehicle.)
>>
>> Tom
>>
> The cooling I discussed was during discharge, which might be useful at
> high ambient temperatures, but that is very dependent on the design
> details, especially the kWh of the battery. You appear to be talking
> about storage temperatures, however, and everyone is agreed cool
> temperatures are better for storage than high temperatures. Owners
> should follow the storage procedures in the glider's operation manual
> to achieve the expected battery lifetime.
>
> Once again, you give us numbers from cars, even though they don't
> apply well to gliders. The temperatures in a glider trailer will be
> much lower than a car interior because it is painted white and does
> not have windows.
>

On Thu, 19 Aug 2021 08:56:06 -0600, Dan Marotta wrote:

> It appears that all sense of humor and irony has left this group.
> ...Unless it's about dick shaped airplanes and rockets.
>
Cheer up - at least Bezos still specialises in building those, though
he's still got a way to go to catch up with the ones in the 'Flesh
Gordon' movie.

--
--
Martin | martin at
Gregorie | gregorie dot org

On Thursday, August 19, 2021 at 7:15:52 AM UTC-7, Eric Greenwell wrote:
> On 8/18/2021 10:17 PM, 2G wrote:
> > On Wednesday, August 18, 2021 at 7:41:28 AM UTC-7, Eric Greenwell wrote:
> >> On 8/18/2021 7:08 AM, Mark Mocho wrote:
> >>> The "other" thread about lithium batteries and design parameters had a suggestion of putting the batteries in the wings with some sort of cooling/heat dissipation method. Tesla uses a water jacket to cool their dense battery packs. Hmmm.. water and electricity. What could go wrong?
> >>>
> >> The wing mounted batteries do not necessarily need cooling. The Antares doesn't have it,
> >> for instance, but designs putting the batteries in an enclosure inside the wing might use
> >> a fan or ram air to move air through it. The box enclosed, fuselage mounted batteries
> >> (FES, ASG32EL, JS3RES, etc) all use fans and electricity - but no one seems puzzled over that.
> >>
> >> And, of course, using water cooling, air cooling, and electricity is absolutely essential
> >> for gasoline gliders - what could go wrong, eh?
> >> --
> >> Eric Greenwell - USA
> >> - "A Guide to Self-launching Sailplane Operation"
> >> https://sites.google.com/site/motorgliders/publications/download-the-guide-1
> >
> > Cooling of lithium batteries is necessary because high temperatures (i.e. 100F) cause degradation of the batteries, and possibly accelerate failure mechanisms, whether the battery is in use or not. Tesla cools their battery packs even if the car is parked. So it doesn't matter where in the glider you mount the batteries. Internal temperatures of cars can reach 140F (https://www.clickorlando.com/news/2019/09/26/heres-how-hot-temperatures-can-get-in-your-car/#:~:text=A%20vehicle%20parked%20in%20the,cabin%20temperature%20of%20116%20degrees.&text=In%20a%20locked%20vehicle%2C%20a,air%20trapped%20inside%20a%20vehicle.)
> >
> > Tom
> >
> The cooling I discussed was during discharge, which might be useful at high ambient
> temperatures, but that is very dependent on the design details, especially the kWh of the
> battery. You appear to be talking about storage temperatures, however, and everyone is
> agreed cool temperatures are better for storage than high temperatures. Owners should
> follow the storage procedures in the glider's operation manual to achieve the expected
> battery lifetime.
>
> Once again, you give us numbers from cars, even though they don't apply well to gliders.
> The temperatures in a glider trailer will be much lower than a car interior because it is
> painted white and does not have windows.
> --
> Eric Greenwell - USA
> - "A Guide to Self-launching Sailplane Operation"
> https://sites.google.com/site/motorgliders/publications/download-the-guide-1

Once again, you give us NO data - what IS the temperature rise inside of a glider trailer? Have you measured it? I didn't think so...

Tom

On 8/18/21 1:17 PM, andy l wrote:
> On Wednesday, 18 August 2021 at 15:08:59 UTC+1, Mark Mocho wrote:
>> The "other" thread about lithium batteries and design parameters had a suggestion of putting the batteries in the wings with some sort of cooling/heat dissipation method. Tesla uses a water jacket to cool their dense battery packs. Hmmm.. water and electricity. What could go wrong?
>
> Fortunately the world's vehicles and electricity supplies were designed by people who weren't defeated by this question.
>

Indeed. Pipistrel is even adding water cooling to their ultralight ships.

https://www.pipistrel-aircraft.com/aircraft/electric-flight/batteries-systems-and-bms/

Even comes with an exhaust port for when those nasty thermal runaways
occur. It's been thoroughly tested in Norway, with nobody getting
electrocuted, nothing blew up, just maybe a few fish died.

https://electrek.co/2019/08/18/electric-plane-crash-lands-into-lake/

But if you're going to crash, try not to do it with high government
mucky-mucks on board during a demo flight.

On 8/20/2021 6:51 AM, kinsell wrote:
>
> Indeed.  Pipistrel is even adding water cooling to their ultralight ships.
>
> https://www.pipistrel-aircraft.com/aircraft/electric-flight/batteries-systems-and-bms/
>
> Even comes with an exhaust port for when those nasty thermal runaways occur.  It's been
> thoroughly tested in Norway, with nobody getting electrocuted, nothing blew up, just maybe
> a few fish died.

These are big batteries at about 12kWh/160lb ea, used in their EASA certified airplanes,
not ultralights.

--
Eric Greenwell - USA
- "A Guide to Self-launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

On Monday, August 16, 2021 at 4:04:30 PM UTC-7, Mark Mocho wrote:
> > http://edition.cnn.com/travel/article/boom-supersonic-four-hours-100-bucks/index.html
>
> OK- some facts that may be relevant:
>
> -Boom Technology is headquartered at Centennial Airport in Colorado.
> -Colorado has legalized recreational cannabis.

Also relevant: At least a couple of their engineers, and their chief test pilot, are active sailplane pilots who you've probably met.

--Bob K.