5th year of living dangerously with LiFePo4 batteries

On Sunday, June 3, 2018 at 9:17:50 PM UTC-7, Frank Whiteley wrote:
On Sunday, June 3, 2018 at 8:15:09 AM UTC-6, Dan Marotta wrote:
Just for balance, has there ever been an inflight fire with a lead-acid
battery?Â* I can't find an instance with a quick google search.

On 6/3/2018 7:50 AM, kinsell wrote:
On 06/03/2018 06:48 AM, krasw wrote:
On Sunday, 3 June 2018 08:20:42 UTC+3, jfitchÂ* wrote:
Got it at the beginning of the 2014 season, 12AH Starkpower. Last
year I got the CBA battery tester. At the beginning of last year it
tested at 11.908 AH (down to 11 V) at a 1.5A load. Just tested it
again and got 11.820AH. My panel is drawing about 1.3A if I don't
turn on the solar charger, so I'm limited to 9 hour flights. It
would be 14 hours with the solar, but of course the sun is gone by
then. Oh well.

I've had 12AH AGMs made by Panasonic and others last about 3 seasons
at most, best to replace them after 2, and generally they would be
below 11.5 volts by the end of the 6 hour day even in the first season.

Now I know I take my life into my hands every time I load the LFP
into the glider, but I intend to continue taking the risk.

Last week there was (to my knowledge) first case of LFPs catching
fire in glider. Luckily the glider was close to airfield and landed
immediately. Primary structures were not damaged but it was a matter
of minute or two, and pilots considered using parachutes. I thought
LFPs were pretty safe but now we know better.


"We" know better?Â* Be careful about including Jon in that, he's made
quite a career out of trying to convince people to use lithium.

Do people really think they're that foolproof?Â* Are you guys not
familiar with Google and YouTube?


http://www.batteryvehiclesociety.org...pic.php?t=1825


--
Dan, 5J

2-33 in Virginia a few years ago. Not a battery fire, but a wiring short to the fuselage that resulted in the fabric burning the glider being landed in trees.

https://app.ntsb.gov/pdfgenerator/Re...Final&IType=LA

Here is a scientific comparison (experiment) of thermal runaway of Li-Ion batteries:
file:///C:/Users/tom_s/Downloads/batteries-03-00014.pdf
Notable is that LiFP batteries could not be provoked into thermal runaway. The reason for this is that the oxygen molecules are covalently bonded to a metal (iron) and doesn't disassociate when heated until very high temps are reached.

Tom

Ive seen SLA batteries in UPS systems swell up and catch fire, at the local recycling yard.

On 06/03/2018 09:18 AM, Nick Kennedy wrote:


So is the problem of a fire caused by a dead short across the battery terminals?

No reason to jump to an assumption like that. Fires with other lithium
chemistries have generally not involved shorts on the terminals. When
those FES gliders lit up recently, nobody was dropping wrenches on them.

Be interesting to find out what really happened with this LFP.

On Monday, 4 June 2018 02:01:18 UTC+3, jfitch wrote:
On Sunday, June 3, 2018 at 8:29:08 AM UTC-7, Richard Pfiffner wrote:
On Sunday, June 3, 2018 at 8:18:49 AM UTC-7, Nick Kennedy wrote:
So is the problem of a fire caused by a dead short across the battery terminals?
Shouldn't a inline fuse coming off the positive terminal take care of any fire problem? I realize a wrench or something like it placed across the terminals would cause a massive short and possible fire, but lacking that, whats the problem?
Do these things spontaneously combust? I have two in my ship and want to know.

I shorted two different batteries, by placing upside down on a metal plate.

The LiFEPO4 was a non event. The battery management shut down immediately.

On the other hand the Lead Acid got quite hot melted the case.

Richard

There you go bringing real data into the discussion again.

I would like krasw to elaborate on the event, if he knows more. Anything that stores energy is potentially dangerous. The devil is in the details.

So far I have no other info, battery was smoking after removed from the glider. Was it LFP cells or BMS electronics, I don't know.

On Monday, June 4, 2018 at 6:55:55 AM UTC-7, krasw wrote:
On Monday, 4 June 2018 02:01:18 UTC+3, jfitch wrote:
On Sunday, June 3, 2018 at 8:29:08 AM UTC-7, Richard Pfiffner wrote:
On Sunday, June 3, 2018 at 8:18:49 AM UTC-7, Nick Kennedy wrote:
So is the problem of a fire caused by a dead short across the battery terminals?
Shouldn't a inline fuse coming off the positive terminal take care of any fire problem? I realize a wrench or something like it placed across the terminals would cause a massive short and possible fire, but lacking that, whats the problem?
Do these things spontaneously combust? I have two in my ship and want to know.

I shorted two different batteries, by placing upside down on a metal plate.

The LiFEPO4 was a non event. The battery management shut down immediately.

On the other hand the Lead Acid got quite hot melted the case.

Richard

There you go bringing real data into the discussion again.

I would like krasw to elaborate on the event, if he knows more. Anything that stores energy is potentially dangerous. The devil is in the details.

So far I have no other info, battery was smoking after removed from the glider. Was it LFP cells or BMS electronics, I don't know.

Keeping sco so far we have one FAA documented fire due to an SLA battery leading to the loss of the aircraft, against a rumor of a smoking battery that may or may not have been LFP which was removed from the glider on landing without damage to it. Other lithium chemistries are irrelevant, unless you are using those in your glider (such as the FES).

I know of one glider here in Canada which burnt up while in the trailer as a result of a metal rigging aid falling onto the battery (placed in the trailer's cargo area) and shorting it out. I also had a few pictures, lost when an old hard drive died that a club member sent me of a glider that had the battery short out and burn fortunately before takeoff. Recently someone I knew improperly charged the batteries that reside under the cockpit floor of his ship and I think he's lucky that the cases didn't burst - they were swollen so much that getting them out was rather difficult. All were SLA batteries.

These incidents say more about the need to protect the battery terminal area well and include a fuse as close as possible to the terminals (a set up like the Dittel battery box for example) and use a good charger than they do about chemistry though.

On 06/04/2018 09:59 AM, jfitch wrote:
On Monday, June 4, 2018 at 6:55:55 AM UTC-7, krasw wrote:
On Monday, 4 June 2018 02:01:18 UTC+3, jfitch wrote:
On Sunday, June 3, 2018 at 8:29:08 AM UTC-7, Richard Pfiffner wrote:
On Sunday, June 3, 2018 at 8:18:49 AM UTC-7, Nick Kennedy wrote:
So is the problem of a fire caused by a dead short across the battery terminals?
Shouldn't a inline fuse coming off the positive terminal take care of any fire problem? I realize a wrench or something like it placed across the terminals would cause a massive short and possible fire, but lacking that, whats the problem?
Do these things spontaneously combust? I have two in my ship and want to know.

I shorted two different batteries, by placing upside down on a metal plate.

The LiFEPO4 was a non event. The battery management shut down immediately.

On the other hand the Lead Acid got quite hot melted the case.

Richard

There you go bringing real data into the discussion again.

I would like krasw to elaborate on the event, if he knows more. Anything that stores energy is potentially dangerous. The devil is in the details.

So far I have no other info, battery was smoking after removed from the glider. Was it LFP cells or BMS electronics, I don't know.

Keeping sco so far we have one FAA documented fire due to an SLA battery leading to the loss of the aircraft, against a rumor of a smoking battery that may or may not have been LFP which was removed from the glider on landing without damage to it. Other lithium chemistries are irrelevant, unless you are using those in your glider (such as the FES).


Wow! Did you read a different report than I did? What I saw was from
the NTSB (the folks who do the investigations), it used the term "gell
cell" instead of SLA, and most importantly it assigned no blame to the
battery. It said there was enough fire damage that they couldn't
determine if there was arcing on the terminals. They did find signs of
arcing on the wiring. That's quite a jump to calling it a "fire due to
an SLA battery", isn't it?

Apparently a "rumor" is something you don't want to believe, and a
"fact" is something you do.

On Tuesday, June 5, 2018 at 7:08:03 AM UTC-7, kinsell wrote:
On 06/04/2018 09:59 AM, jfitch wrote:
On Monday, June 4, 2018 at 6:55:55 AM UTC-7, krasw wrote:
On Monday, 4 June 2018 02:01:18 UTC+3, jfitch wrote:
On Sunday, June 3, 2018 at 8:29:08 AM UTC-7, Richard Pfiffner wrote:
On Sunday, June 3, 2018 at 8:18:49 AM UTC-7, Nick Kennedy wrote:
So is the problem of a fire caused by a dead short across the battery terminals?
Shouldn't a inline fuse coming off the positive terminal take care of any fire problem? I realize a wrench or something like it placed across the terminals would cause a massive short and possible fire, but lacking that, whats the problem?
Do these things spontaneously combust? I have two in my ship and want to know.

I shorted two different batteries, by placing upside down on a metal plate.

The LiFEPO4 was a non event. The battery management shut down immediately.

On the other hand the Lead Acid got quite hot melted the case.

Richard

There you go bringing real data into the discussion again.

I would like krasw to elaborate on the event, if he knows more. Anything that stores energy is potentially dangerous. The devil is in the details.

So far I have no other info, battery was smoking after removed from the glider. Was it LFP cells or BMS electronics, I don't know.

Keeping sco so far we have one FAA documented fire due to an SLA battery leading to the loss of the aircraft, against a rumor of a smoking battery that may or may not have been LFP which was removed from the glider on landing without damage to it. Other lithium chemistries are irrelevant, unless you are using those in your glider (such as the FES).


Wow! Did you read a different report than I did? What I saw was from
the NTSB (the folks who do the investigations), it used the term "gell
cell" instead of SLA, and most importantly it assigned no blame to the
battery. It said there was enough fire damage that they couldn't
determine if there was arcing on the terminals. They did find signs of
arcing on the wiring. That's quite a jump to calling it a "fire due to
an SLA battery", isn't it?

Apparently a "rumor" is something you don't want to believe, and a
"fact" is something you do.

A couple of facts: A gel battery IS an SLA battery. Its I/V characteristics and chemistry are substantially identical to an AGM, which is also an SLA battery. The only difference is in how the acid is immobilized. Second fact, a battery - any battery - does not spontaneously combust. If they do so, it is while being charged or discharged, usually under out-of-spec circumstances. Another fact: most electrical fires are caused by faults in wiring. Some further facts: the incident in question was caused without question by the SLA battery. It was an electrical fire which would not have occurred had the battery not been present, and therefore a proximate cause. A fact that you will find very inconvenient: had that battery been a properly constructed LFP, the incident would not have occurred. As Richard has pointed out above, the BMS would simply have disconnected the output and the glider would have landed without incident. For mitigation of wiring faults (by far the highest cause of electrical fires) an LFP is much safer than an SLA battery, which has no such protections.

Once again, you can use whatever battery you like, but you don't get to use "alternative facts".

And finally, I do believe in facts, and I don't (necessarily) believe in rumors.

On Tuesday, June 5, 2018 at 9:55:30 AM UTC-6, jfitch wrote:
On Tuesday, June 5, 2018 at 7:08:03 AM UTC-7, kinsell wrote:
On 06/04/2018 09:59 AM, jfitch wrote:
On Monday, June 4, 2018 at 6:55:55 AM UTC-7, krasw wrote:
On Monday, 4 June 2018 02:01:18 UTC+3, jfitch wrote:
On Sunday, June 3, 2018 at 8:29:08 AM UTC-7, Richard Pfiffner wrote:
On Sunday, June 3, 2018 at 8:18:49 AM UTC-7, Nick Kennedy wrote:
So is the problem of a fire caused by a dead short across the battery terminals?
Shouldn't a inline fuse coming off the positive terminal take care of any fire problem? I realize a wrench or something like it placed across the terminals would cause a massive short and possible fire, but lacking that, whats the problem?
Do these things spontaneously combust? I have two in my ship and want to know.

I shorted two different batteries, by placing upside down on a metal plate.

The LiFEPO4 was a non event. The battery management shut down immediately.

On the other hand the Lead Acid got quite hot melted the case.

Richard

There you go bringing real data into the discussion again.

I would like krasw to elaborate on the event, if he knows more. Anything that stores energy is potentially dangerous. The devil is in the details.

So far I have no other info, battery was smoking after removed from the glider. Was it LFP cells or BMS electronics, I don't know.

Keeping sco so far we have one FAA documented fire due to an SLA battery leading to the loss of the aircraft, against a rumor of a smoking battery that may or may not have been LFP which was removed from the glider on landing without damage to it. Other lithium chemistries are irrelevant, unless you are using those in your glider (such as the FES).


Wow! Did you read a different report than I did? What I saw was from
the NTSB (the folks who do the investigations), it used the term "gell
cell" instead of SLA, and most importantly it assigned no blame to the
battery. It said there was enough fire damage that they couldn't
determine if there was arcing on the terminals. They did find signs of
arcing on the wiring. That's quite a jump to calling it a "fire due to
an SLA battery", isn't it?

Apparently a "rumor" is something you don't want to believe, and a
"fact" is something you do.

A couple of facts: A gel battery IS an SLA battery. Its I/V characteristics and chemistry are substantially identical to an AGM, which is also an SLA battery. The only difference is in how the acid is immobilized. Second fact, a battery - any battery - does not spontaneously combust. If they do so, it is while being charged or discharged, usually under out-of-spec circumstances. Another fact: most electrical fires are caused by faults in wiring.. Some further facts: the incident in question was caused without question by the SLA battery. It was an electrical fire which would not have occurred had the battery not been present, and therefore a proximate cause. A fact that you will find very inconvenient: had that battery been a properly constructed LFP, the incident would not have occurred. As Richard has pointed out above, the BMS would simply have disconnected the output and the glider would have landed without incident. For mitigation of wiring faults (by far the highest cause of electrical fires) an LFP is much safer than an SLA battery, which has no such protections.

Once again, you can use whatever battery you like, but you don't get to use "alternative facts".

And finally, I do believe in facts, and I don't (necessarily) believe in rumors.

Fitchy, Here is a "Fact" you may find inconvenient, You could stand to lighten up. An electrical fire in ANY glider with a battery installed would not occur if it were not present (Laughing), now would it? Whats your point? Granted they guy got the name a little mixed up (AGM, SLA, Gel Cel, whatever) but a proper SLA or AMG installation is as safe as anything out there. Why do you think auto manufacturers have been putting terminal covers on batteries for the past 30 years or so? Post crash fire protection.

Kirk

And finally, I believe in facts, but I also like rumors, innuendo, wives tales urban legends, hoaxes, and a lot of the stuff on RAS.

On Tuesday, June 5, 2018 at 12:21:08 PM UTC-6, K m wrote:
On Tuesday, June 5, 2018 at 9:55:30 AM UTC-6, jfitch wrote:
On Tuesday, June 5, 2018 at 7:08:03 AM UTC-7, kinsell wrote:
On 06/04/2018 09:59 AM, jfitch wrote:
On Monday, June 4, 2018 at 6:55:55 AM UTC-7, krasw wrote:
On Monday, 4 June 2018 02:01:18 UTC+3, jfitch wrote:
On Sunday, June 3, 2018 at 8:29:08 AM UTC-7, Richard Pfiffner wrote:
On Sunday, June 3, 2018 at 8:18:49 AM UTC-7, Nick Kennedy wrote:
So is the problem of a fire caused by a dead short across the battery terminals?
Shouldn't a inline fuse coming off the positive terminal take care of any fire problem? I realize a wrench or something like it placed across the terminals would cause a massive short and possible fire, but lacking that, whats the problem?
Do these things spontaneously combust? I have two in my ship and want to know.

I shorted two different batteries, by placing upside down on a metal plate.

The LiFEPO4 was a non event. The battery management shut down immediately.

On the other hand the Lead Acid got quite hot melted the case.

Richard

There you go bringing real data into the discussion again.

I would like krasw to elaborate on the event, if he knows more. Anything that stores energy is potentially dangerous. The devil is in the details.

So far I have no other info, battery was smoking after removed from the glider. Was it LFP cells or BMS electronics, I don't know.

Keeping sco so far we have one FAA documented fire due to an SLA battery leading to the loss of the aircraft, against a rumor of a smoking battery that may or may not have been LFP which was removed from the glider on landing without damage to it. Other lithium chemistries are irrelevant, unless you are using those in your glider (such as the FES).


Wow! Did you read a different report than I did? What I saw was from
the NTSB (the folks who do the investigations), it used the term "gell
cell" instead of SLA, and most importantly it assigned no blame to the
battery. It said there was enough fire damage that they couldn't
determine if there was arcing on the terminals. They did find signs of
arcing on the wiring. That's quite a jump to calling it a "fire due to
an SLA battery", isn't it?

Apparently a "rumor" is something you don't want to believe, and a
"fact" is something you do.

A couple of facts: A gel battery IS an SLA battery. Its I/V characteristics and chemistry are substantially identical to an AGM, which is also an SLA battery. The only difference is in how the acid is immobilized. Second fact, a battery - any battery - does not spontaneously combust. If they do so, it is while being charged or discharged, usually under out-of-spec circumstances. Another fact: most electrical fires are caused by faults in wiring. Some further facts: the incident in question was caused without question by the SLA battery. It was an electrical fire which would not have occurred had the battery not been present, and therefore a proximate cause. A fact that you will find very inconvenient: had that battery been a properly constructed LFP, the incident would not have occurred. As Richard has pointed out above, the BMS would simply have disconnected the output and the glider would have landed without incident. For mitigation of wiring faults (by far the highest cause of electrical fires) an LFP is much safer than an SLA battery, which has no such protections.

Once again, you can use whatever battery you like, but you don't get to use "alternative facts".

And finally, I do believe in facts, and I don't (necessarily) believe in rumors.

Fitchy, Here is a "Fact" you may find inconvenient, You could stand to lighten up. An electrical fire in ANY glider with a battery installed would not occur if it were not present (Laughing), now would it? Whats your point? Granted they guy got the name a little mixed up (AGM, SLA, Gel Cel, whatever) but a proper SLA or AMG installation is as safe as anything out there.. Why do you think auto manufacturers have been putting terminal covers on batteries for the past 30 years or so? Post crash fire protection.

Kirk

And finally, I believe in facts, but I also like rumors, innuendo, wives tales urban legends, hoaxes, and a lot of the stuff on RAS.

Sadly, not entirely unrelated to this thread. This was the plane used in the recent glider tow.

https://electrek.co/2018/06/04/sieme...e-crash-death/

Frank Whiteley