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