A post EV era

[gruntguru]

People seem rather keen on attaching failing highly inflammable batteries to their houses.I wonder what the insurance people will have to say?

What, as opposed to parking a vehicle with a tank full of highly flammable liquid in the garage?

"I don't like something so I'll make up some rubbish to support my view".

ICE are just as dangerous as an EV near a house.

He's talking about installing a used EV battery in a house.

[Greg Locock]

You two (not gg) miss my point in your self righteous hurry to correct me. These batteries, with the more exciting chemistry, taken off a BEV because they are failing, are then going to be screwed to your house, where presumably they will continue to fail. You are gambling that they will fail gracefully. Your insurance company may think that that was not what they signed up to.

[Andres125sx]

You two (not gg) miss my point in your self righteous hurry to correct me. These batteries, with the more exciting chemistry, taken off a BEV because they are failing, are then going to be screwed to your house, where presumably they will continue to fail. You are gambling that they will fail gracefully. Your insurance company may think that that was not what they signed up to.

An old battery do not fail, or they do (as any other component of any car), but when a battery is too old it´s not that the cells fail, but the charge/discharge rating is decreased so it can´t hold the necessary voltage (voltage sag increases) and cut-off when in theory it´s not fully discharged yet. That´s the reason range is decreased when a battery is old.

But charge/discharge rate is only a problem for vehicles, wich need a high output (a lot of kW), while on a house the demand is several orders of magnitude lower so it´s not a problem if the discharge rate is lower.

In other words, an old battery for an EV is perfectly fine for a house, even for many more years

[J.A.W.]

Unless/until it catches fire, & duly burns well beyond the capability of any practicable household fire-quelling...

[Just_a_fan]

Faulty gas appliances cause explosions that demolish houses, but it doesn't stop people having gas in their house for heating/cooking.

[Greg Locock]

Of course enthusiasts often claim they can use degrading systems in untested environments. Challenger O rings anybody?

[J.A.W.]

Faulty gas appliances cause explosions that demolish houses, but it doesn't stop people having gas in their house for heating/cooking.

A gas alarm will give warning, & the quantum of a household-level pressure-regulated gas emission is fairly low - in
(esp' a 'pilot light') terms of heat/unit/time-energy - plus of course, turn a valve by the metering unit & it shuts off...

Li fires tend to grow exponentially, as the thermo-chemical reaction evolves, & shutting them down then, aint so easy.

[Just_a_fan]

Challenger was a political failure - it flew because management didn't want to push the launch back again, especially as there was a State of the Nation address scheduled for the same day as the launch - a good bit of PR for NASA to have the teacher in space as Reagan gave his address.

The engineers were against Challenger launching. Management overruled them.

[Just_a_fan]

Faulty gas appliances cause explosions that demolish houses, but it doesn't stop people having gas in their house for heating/cooking.

A gas alarm will give warning, & the quantum of a household-level pressure-regulated gas emission is fairly low - in
(esp' a 'pilot light') terms of heat/unit/time-energy - plus of course, turn a valve by the metering unit & it shuts off...

Li fires tend to grow exponentially, as the thermo-chemical reaction evolves, & shutting them down then, aint so easy.

And yet still houses are demolished and people killed by gas explosions.

[J.A.W.]

Faulty gas appliances cause explosions that demolish houses, but it doesn't stop people having gas in their house for heating/cooking.

A gas alarm will give warning, & the quantum of a household-level pressure-regulated gas emission is fairly low - in
(esp' a 'pilot light') terms of heat/unit/time-energy - plus of course, turn a valve by the metering unit & it shuts off...

Li fires tend to grow exponentially, as the thermo-chemical reaction evolves, & shutting them down then, aint so easy.

And yet still houses are demolished and people killed by gas explosions.

You want to 'break down' those events, causation-wise?

Mains-pressure 'big-bang' failure in poorly maintained gas systems are avoidable/indicative of shoddy work.
& ?% of domestic events as sabotage/criminal/self-community abuse types of conduct - for some nefarious-destructive, purpose?

In the case of an Li 'power-wall' mass-take-up, you can surely add those potentialities as well, of course, too...

[Just_a_fan]

If I were to have a battery storage system, I would place it outside the building and have a water spray head positioned to spray water on adjacent structure. Then the battery can burn itself out but adjacent structures won't catch fire. It's about all one can do with a lithium battery fire. If I had to have the system inside a building, it would be in its own compartment constructed to contain the fire. Not a difficult thing to build but one obviously has to factor it in to the overall project. Even a battery in a garage would be "interesting". In the UK the garage is required to be separated from the house by fire resisting construction, but it's only to a 30 minutes standard - to allow time for the fire brigade to arrive and do their thing. It would be trivially easy to increase the level of protection to, for example, 120 minutes if a battery was going to be installed in the garage.

[Andres125sx]

Unless/until it catches fire, & duly burns well beyond the capability of any practicable household fire-quelling...

True, things work unless they fail, catch fire, and are incinerated. That's not exclusive of batteries tough


https://www.telegraph.co.uk/motoring/ca ... fires.html

[J.A.W.]

Hey man, Italian electrical/cooling systems, 'What ya gonna do?'

Hell, I still have a 30 year old classic M-B which will run aux-fans/coolant electrically - after engine shutdown
in hot weather - to prevent engine compartment heat-soak issues such as component failure/petrol boil-off..

[hollus]

Surely by now there must be some real world statistics /hjhuuum/ data, on household lithium battery fires?

[Andres125sx]

Of course enthusiasts often claim they can use degrading systems in untested environments. Challenger O rings anybody?

It´s not a matter of enthusiasts, but a matter of data and understanding how things work Greg

For an EV you need a high output from the battery, as it must provide 60kW or 500kW maybe, depending on the power of the car. If it´s a small and not very powerful car with 60kW and a 40kWh battery, the battery must provide 1.5C discharge rate. If it´s a tesla with 500kW and 100kWh battery, it´s 5C.

A standard home draw 1-5kW, wich will be 0.02-0.12C with a 40kWh battery, or 0.01-0.05C with a 100kWh battery.

So any battery must provide 1.5-5C when into an EV, and 0.01-0.12C when in a home, wich means the power demanded to the battery is reduced by a factor of 10 at least, or most probably even higher than 50. Charge rates are reduced even further.

OTOH, batteries catch fire when they get too hot, and they get hot when they´re discharged (or charged) at high rates. When the rate is reduced by a factor of 20-30 from a starting rate wich is ok for the battery, the safety margin is several orders of magnitude higher than any other component into any house or car.


It´s not a matter of enthusiast, it´s a matter of science, data and understanding how things work.