LiFePo Refit Part 23 AC

SLA needs replacement and aircraft is part 23 utility. A LiFePo in the same foot print would be great, I definitely see folks using them and no less than three online stores selling them.

So I started looking at AC 20-184 which seems to be the FAA equivalent of trial by ordeal. Okay, I get it. They aren't quite as proven as SLA and a few have self immolated.

I've found at least a couple of EASA approvals that are sailplane specific but nothing that satisfies the lengthy list of hurdles the FSDO would likely accept.

Thoughts? Suggestions? Am I overthinking this?

Shaun Wheeler wrote on 2/26/2020 6:55 AM:
SLA needs replacement and aircraft is part 23 utility. A LiFePo in the same foot print would be great, I definitely see folks using them and no less than three online stores selling them.

So I started looking at AC 20-184 which seems to be the FAA equivalent of trial by ordeal. Okay, I get it. They aren't quite as proven as SLA and a few have self immolated.

I've found at least a couple of EASA approvals that are sailplane specific but nothing that satisfies the lengthy list of hurdles the FSDO would likely accept.

Thoughts? Suggestions? Am I overthinking this?

What is the aircraft that needs the battery? None of the gliders I've had
specified the chemistry of the instrument battery, and those were all easily
removable, suggesting they are "portable" units and not part of the aircraft.


--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

L33 solo.

On Wednesday, February 26, 2020 at 1:13:46 PM UTC-8, Shaun Wheeler wrote:
L33 solo.

This may be of interest:
http://jdasolutions.aero/blog/faas-p...val-standards/

https://www.aviationpros.com/engines...es-in-aircraft

This is a TSO'd 12V battery:
https://earthxbatteries.com/product-...ified-aircraft

To get approved it looks like any lithium ion battery will need a hardened case with venting to the outside of the A/C.

Tom

Shaun Wheeler wrote on 2/26/2020 1:13 PM:
L33 solo.

Does the handbook specify the type of battery required for the instruments, or
prohibit LiFe batteries? If not, and it's easily removable, I think you can
reasonably claim it's a portable device and use one of your choosing in the
glider; after all, you likely have Lithium batteries in it already - your cell
phone, your inReach/Spot, your logger, and a handheld radio.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

On Thursday, February 27, 2020 at 12:43:21 AM UTC-5, 2G wrote:
On Wednesday, February 26, 2020 at 1:13:46 PM UTC-8, Shaun Wheeler wrote:
L33 solo.

This may be of interest:
http://jdasolutions.aero/blog/faas-p...val-standards/

https://www.aviationpros.com/engines...es-in-aircraft

This is a TSO'd 12V battery:
https://earthxbatteries.com/product-...ified-aircraft

To get approved it looks like any lithium ion battery will need a hardened case with venting to the outside of the A/C.

Tom

"at an incredible introductory price of $699"

This is for a starter type/size battery (it says "840 Peak cranking amp").

Curiously that web page does not say what the chemistry is, other than "lithium", but the PDF brochure says "Custom made prismatic LiFePo4 cells".

I wonder: the (large, installed) lithium batteries that caught fire on some airliners, what chemistry were they?

At 17:17 27 February 2020, wrote:
On Thursday, February 27, 2020 at 12:43:21 AM UTC-5, 2G
wrote:
On Wednesday, February 26, 2020 at 1:13:46 PM UTC-8,
Shaun Wheeler wrote:
L33 solo.

This may be of interest:

http://jdasolutions.aero/blog/faas-p...m-ion-battery-
approval-standards/


https://www.aviationpros.com/engines...ents/aircraft-
airframe-accessories/batteries/article/12256058/lithiumion-
batteries-in-aircraft

This is a TSO'd 12V battery:
https://earthxbatteries.com/product-...ified-aircraft

To get approved it looks like any lithium ion battery will need a
hardened case with venting to the outside of the A/C.

Tom

"at an incredible introductory price of $699"

This is for a starter type/size battery (it says "840 Peak cranking
amp").

Curiously that web page does not say what the chemistry is,
other than
"lithium", but the PDF brochure says "Custom made prismatic
LiFePo4 cells".

I wonder: the (large, installed) lithium batteries that caught fire
on some
airliners, what chemistry were they?

The DreamLiner batteries were LiPo (Lithium Polymer) I think. I
understand they are now in an externally vented metal box? Any
Boeing pilots like to confirm?

On 2/27/20 10:37 AM, Dave Walsh wrote:
At 17:17 27 February 2020, wrote:
On Thursday, February 27, 2020 at 12:43:21 AM UTC-5, 2G
wrote:
On Wednesday, February 26, 2020 at 1:13:46 PM UTC-8,
Shaun Wheeler wrote:
L33 solo.

This may be of interest:

http://jdasolutions.aero/blog/faas-p...m-ion-battery-
approval-standards/


https://www.aviationpros.com/engines...ents/aircraft-
airframe-accessories/batteries/article/12256058/lithiumion-
batteries-in-aircraft

This is a TSO'd 12V battery:
https://earthxbatteries.com/product-...ified-aircraft

To get approved it looks like any lithium ion battery will need a
hardened case with venting to the outside of the A/C.

Tom

"at an incredible introductory price of $699"

This is for a starter type/size battery (it says "840 Peak cranking
amp").

Curiously that web page does not say what the chemistry is,
other than
"lithium", but the PDF brochure says "Custom made prismatic
LiFePo4 cells".

I wonder: the (large, installed) lithium batteries that caught fire
on some
airliners, what chemistry were they?

The DreamLiner batteries were LiPo (Lithium Polymer) I think. I
understand they are now in an externally vented metal box? Any
Boeing pilots like to confirm?


Not a Boeing pilot, but they are lithium cobalt, like is used in most
electric motorgliders. Yes the 787 now uses steel boxes vented to the
outside.

But LiFePO4 have also been known to burn. EarthX says to vent them to
the outside, but don't believe they recommend fire-proof boxes.

Dave

The 'official' maintenance manual lists to model numbers, "NKDU 10" and "NKDU 10R" as optional equipment in the supplement index. This aircraft shipped with a Becker 3201 so it should also have shipped with the NKDU 10R battery, but the page for the battery "maintenance and operation" is missing. Neither battery appears to be in production anywhere these days. It's not listed on EASA either, I checked.

I did look through some of the reported fires before I asked about this. With a battery box, fuse and the correct hardware the risk for an aircraft that cannot recharge the cells in flight is almost non-existent.

Found a copy of the supplement page online.

The NKDU appears to have been NiCad cell strings with fillers that seal if rotated off 90 degrees. I'm not a chemist or a mechanical engineer (online or elsewhere) but that's my best translation of the electrolyte they want added.

I found where EASA and the FAA are trying to come up with something to solve this.

Most sailplanes aren't going to recharge in flight. That removes almost half the issues related to lithium cells on the front end. The electronics to balance cells are only relevant during the charging process. IMNSHO, they should waive those requirements on anything that does NOT require or provide for in-flight charging at any rate greater than what can be done with PV.

Anyways, thanks for the input. I think I've figured out what I'm going to do and thankfully, I'm not the only one doing it so if I'm wrong, well, I'm wrong in a lot of august company