A
Anthony William Sloman
Guest
Flyguy has this nasty habit of claiming that I want to fire bomb my own country.
There was a thread about electric aircraft, and Flyguy came up with an accident report about an ultralight aircraft that had caught on fire. essentially because it\'s owner had abused the batteries.
I suggested that it would make sense to dump an overheating battery pack before it caught on fire.
Flyguy over-simplified this into a recommendation that the pilot dumped burning batteries.
He seems to have decided that batteries can only have two states \"okay\" or \"on fire\".
In reality, batteries always self-discharge to some extent, so they are always a bit warmer than ambient.
This doesn\'t get to be a problem until the self-heating gets to a point where it starts increasing the self-discharge rate.
At some point the battery can eventually go into thermal runaway, when the battery temperature starts rising rapidly and the battery pack can eventually catch on fire.
If you monitor the internal temperature of the battery pack, you can recognise when this is starting to happen - long before the battery catches on fire - and dump the batteries.
If you make sure that battery pack breaks up as you dump it, it won\'t get as hot and may never ever catch on fire.
So it shouldn\'t look like a bunch of fire bombs before it hits the ground.
If you pick up on the temperature rise early enough, the individual cells should never get hot enough to catch on fire once they have been spread out enough not to warm up their neighbors.
All this is much to complicated for Flyguy to process, though I have explained it from time to time. It may be that he really is a stupid as he looks, or he may not feel the need to put in the effort required to realise that he\'s being an idiot.
--
Bill Sloman, Sydney
There was a thread about electric aircraft, and Flyguy came up with an accident report about an ultralight aircraft that had caught on fire. essentially because it\'s owner had abused the batteries.
I suggested that it would make sense to dump an overheating battery pack before it caught on fire.
Flyguy over-simplified this into a recommendation that the pilot dumped burning batteries.
He seems to have decided that batteries can only have two states \"okay\" or \"on fire\".
In reality, batteries always self-discharge to some extent, so they are always a bit warmer than ambient.
This doesn\'t get to be a problem until the self-heating gets to a point where it starts increasing the self-discharge rate.
At some point the battery can eventually go into thermal runaway, when the battery temperature starts rising rapidly and the battery pack can eventually catch on fire.
If you monitor the internal temperature of the battery pack, you can recognise when this is starting to happen - long before the battery catches on fire - and dump the batteries.
If you make sure that battery pack breaks up as you dump it, it won\'t get as hot and may never ever catch on fire.
So it shouldn\'t look like a bunch of fire bombs before it hits the ground.
If you pick up on the temperature rise early enough, the individual cells should never get hot enough to catch on fire once they have been spread out enough not to warm up their neighbors.
All this is much to complicated for Flyguy to process, though I have explained it from time to time. It may be that he really is a stupid as he looks, or he may not feel the need to put in the effort required to realise that he\'s being an idiot.
--
Bill Sloman, Sydney