Lithium battery power tool

PW_Plack

Active Member
Joined
Oct 30, 2003
Messages
8,507
Location
West Valley City, Utah, USA
Aircraft
Sport Copter Vortex 582
Total Flight Time
FW: 200 Gyro: 51
...anything above a 0% chance of failure would make me nervous to fly with.
...says the guy planning to fly with a two-stroke! But seriously, Brian, old-school lead-acid batteries can fail catastrophically, too. From what I've seen of your level of care, you'll not likely have an issue with either type. I don't think the alternator on a 503 can exceed the max charge-rate rating of any battery designed to start the engine, although it could exceed the battery's max voltage on a long flight.

I did have a catastrophic battery failure once - the lead-acid Sears Diehard battery in my '69 Torino. The charging regulator failed and overcharged the battery, which exploded under the hood, scattering plastic and acid all over the engine compartment. From inside the car, it sounded like a backfire, so I continued driving to work. When I came out to drive home, the car started normally, but the throttle linkage was sticking due to rapid corrosion. When I pulled into a gas station to check under the hood, all that was left of the battery was the plates, sitting in about an inch of acid in what was left of the bottom of the battery case. The car was pretty much ruined by acid damage. Obviously, a failure like this in flight could be unpleasant in a number of ways.

If the rectifier/regulator in a typical Rotax setup failed, or if it even lost its ground connection, the same thing could happen to any battery. If it's an issue of confidence, enclose the battery in an ammo case, vented out one side away from fuel system components, and monitor battery voltage in your panel, preferably independent of the aircraft's main power bus and frame ground.

I just retired from a job in which I managed a pool of lithium-ion batteries used in computerized prosthetics. In tens of thousands of repair and maintenance jobs, I never saw one fail that wasn't abused, electrically or physically. In another previous job, we subjected hundreds of smart phones to vacuum deposition of a polymer coating. Some of the lithium-ion batteries puffed up like a pillow and broke the cases of the phones, but none failed catastrophically.

I'm not sure what happened with the lithium batteries which failed during testing of the Boeing 787 a few years ago. I suspect their containers may have constrained their expansion as cabin pressure dropped, causing uneven pressure on their cases, or charge/discharge rates got out of hand.

Most of the videos on YouTube, with the exception of early laptop computers and some Samsung phones, have had their internal protective circuitry intentionally disabled to create a dramatic video. I'd consider any starting battery certified for aircraft use to be as reasonable a risk as any other, provided you don't exceed their ratings or try to charge them at temps below freezing.

The exception, of course, is Ebay/Amazon batteries of unknown origin.
 

Brian Jackson

Platinum Member
Joined
Jul 17, 2004
Messages
2,876
Location
Hamburg, New Jersey USA
Aircraft
GyroBee Variant - Under Construction
...says the guy planning to fly with a two-stroke! But seriously, Brian, old-school lead-acid batteries can fail catastrophically, too. From what I've seen of your level of care, you'll not likely have an issue with either type. I don't think the alternator on a 503 can exceed the max charge-rate rating of any battery designed to start the engine, although it could exceed the battery's max voltage on a long flight.

I did have a catastrophic battery failure once - the lead-acid Sears Diehard battery in my '69 Torino. The charging regulator failed and overcharged the battery, which exploded under the hood, scattering plastic and acid all over the engine compartment. From inside the car, it sounded like a backfire, so I continued driving to work. When I came out to drive home, the car started normally, but the throttle linkage was sticking due to rapid corrosion. When I pulled into a gas station to check under the hood, all that was left of the battery was the plates, sitting in about an inch of acid in what was left of the bottom of the battery case. The car was pretty much ruined by acid damage. Obviously, a failure like this in flight could be unpleasant in a number of ways.

If the rectifier/regulator in a typical Rotax setup failed, or if it even lost its ground connection, the same thing could happen to any battery. If it's an issue of confidence, enclose the battery in an ammo case, vented out one side away from fuel system components, and monitor battery voltage in your panel, preferably independent of the aircraft's main power bus and frame ground.

I just retired from a job in which I managed a pool of lithium-ion batteries used in computerized prosthetics. In tens of thousands of repair and maintenance jobs, I never saw one fail that wasn't abused, electrically or physically. In another previous job, we subjected hundreds of smart phones to vacuum deposition of a polymer coating. Some of the lithium-ion batteries puffed up like a pillow and broke the cases of the phones, but none failed catastrophically.

I'm not sure what happened with the lithium batteries which failed during testing of the Boeing 787 a few years ago. I suspect their containers may have constrained their expansion as cabin pressure dropped, causing uneven pressure on their cases, or charge/discharge rates got out of hand.

Most of the videos on YouTube, with the exception of early laptop computers and some Samsung phones, have had their internal protective circuitry intentionally disabled to create a dramatic video. I'd consider any starting battery certified for aircraft use to be as reasonable a risk as any other, provided you don't exceed their ratings or try to charge them at temps below freezing.

The exception, of course, is Ebay/Amazon batteries of unknown origin.
Paul,

Thank you for that information and explanation. Perhaps my fear is just of the unknown. You've given me some good things to think about and bullet points for research. Since Dave's original post and the subsequent discussion, I'm re-thinking where I had originally intended to place the battery, which you iterated keeping them well clear of fuel systems.

I'm glad you chimed in here on this, especially with your professional background in this technology. Pretty impressive. I will reconsider my stance on the subject. Thanks again Paul.
 

Brian Jackson

Platinum Member
Joined
Jul 17, 2004
Messages
2,876
Location
Hamburg, New Jersey USA
Aircraft
GyroBee Variant - Under Construction
I ran across this today:


Apparently there is a new way to create a lithium-ion battery that is non-flamable/explosive using a different form of electrolyte. Here's hoping it comes to market soon if the testing proves positive.
 

kolibri282

Active Member
Joined
Aug 2, 2009
Messages
2,803
Location
Duesseldorf
Quote: Apparently there is a new way to create a lithium-ion battery /Quote
Very interesting, Brian, there have been a lot of new developments in battery technology in the last few years, so I think we'll see some very amazing stuff in the years to come. This always reminds me of Jules Verne and the Albatros, the mammoth helicopter that Robur le Conquereur is flying. He has some source of almost unlimited battery power. One unbelievable detail is that Verne says the rotor blades of the Albatros are made from a fibre gelatine (as he calls it) combination, which translates to GFK/CFK etc. today. That's what I call visionary!
 

XXavier

Member
Joined
Nov 13, 2006
Messages
921
Location
Madrid, Spain
Aircraft
FW Savannah XL + ELA R-100 and Magni M24 autogyros
Total Flight Time
1394 FW + 526 gyro (Oct. 2019)
Quote: Apparently there is a new way to create a lithium-ion battery /Quote
Very interesting, Brian, there have been a lot of new developments in battery technology in the last few years, so I think we'll see some very amazing stuff in the years to come. This always reminds me of Jules Verne and the Albatros, the mammoth helicopter that Robur le Conquereur is flying. He has some source of almost unlimited battery power. One unbelievable detail is that Verne says the rotor blades of the Albatros are made from a fibre gelatine (as he calls it) combination, which translates to GFK/CFK etc. today. That's what I call visionary!
And if my memory does not fail me, that ship's hull was built with papier-mâché... A very light composite...
Verne was truly a visionary... Perhaps his most surprising prophecy was the use of rockets to change the trajectory of an spacecraft orbiting the Moon...
 
Last edited:
Top