71–80 of 147 posts
https://www.youtube.com/user/jehugarcia
he methodically tests old 18650 laptop cells, sorts them, builds battery packs and so on. He's converted a classic VW bus to electric power using his home-made battery packs and packs salvaged from wrecked teslas.
Given how popular (and damn near impossible to discern) unsafe and unprotected lithium-ion batteries are, the idea of making a homegrown power wall terrifies me in ways I can't even begin to contemplate. An 18650 battery, if combusted, can produce hydrofluoric acid with just water vapor in the air (or the water in your lungs) if they use lithium hexafluorophosphate as the electrolyte. Hydrofluoric acid can and will c…
You have to realize that 1kWh is a lot of energy. Imagine being hit (in a world without an atmosphere) by a 60 pound suitcase falling out of an airliner flying at 45,000 feet. Same amount of energy as that battery pack. (Alternatively: the most powerful air conditioner you can buy running full blast for 30 minutes. Incidentally, that battery pack has as much energy as 100mL of gasoline, which is why gasoline-powered…
I can easily buy a 16 ton (1 ton = 12000 BTU/h) air conditioner, it uses a great deal more than 1kWh in 30 minutes.
http://www.ebay.com/itm/Carrier-16TON-R-410A-Puron-Air-Condi...
What does a Newton-meter of torque feel like? Reopening a plastic soda bottle. From a web interactive I wrote: http://www.clarifyscience.info/part/ZoomB?v=A&p=CK6Ji&m=torq... (2014)
> Newton-meter I do not know why (and I do not have a strong opinion on this), but somehow this (relatively recent) tradition of naming units after people feels weird to me. I know we are already used to these units, but imagine the unit of mass was called Einstein instead of kilogram.
Earlier quoted context omitted.
As a reference point, a Tesla 85D uses 290 watt-hours to go one EPA rated mile. So 1 kWh takes you 3.448 miles.
> one EPA rated mile Are EPA miles not the same as normal miles?
If you like this, watch the videos from this guy: https://www.youtube.com/user/jehugarcia he methodically tests old 18650 laptop cells, sorts them, builds battery packs and so on. He's converted a classic VW bus to electric power using his home-made battery packs and packs salvaged from wrecked teslas.
Wait what? where is this supply at
Earlier quoted context omitted.
It wouldn't be quite that bad. You're probably putting out something like 100-200W. Even factoring in generating and storage losses, you're looking at running a reasonably bright LED bulb for several hours on the proceeds of a 30-minute session. Still not worth the effort of building the equipment, of course.
200w seems for pro cyclists. 100w for above average sports fan. Today lots of computing devices fall under 10w power usage. Hence my daydream. For light or electric appliances that's another story.
What does a Newton-meter of torque feel like? Reopening a plastic soda bottle. From a web interactive I wrote: http://www.clarifyscience.info/part/ZoomB?v=A&p=CK6Ji&m=torq... (2014)
> Newton-meter I do not know why (and I do not have a strong opinion on this), but somehow this (relatively recent) tradition of naming units after people feels weird to me. I know we are already used to these units, but imagine the unit of mass was called Einstein instead of kilogram.
Given how popular (and damn near impossible to discern) unsafe and unprotected lithium-ion batteries are, the idea of making a homegrown power wall terrifies me in ways I can't even begin to contemplate. An 18650 battery, if combusted, can produce hydrofluoric acid with just water vapor in the air (or the water in your lungs) if they use lithium hexafluorophosphate as the electrolyte. Hydrofluoric acid can and will c…
You have to realize that 1kWh is a lot of energy. Imagine being hit (in a world without an atmosphere) by a 60 pound suitcase falling out of an airliner flying at 45,000 feet. Same amount of energy as that battery pack. (Alternatively: the most powerful air conditioner you can buy running full blast for 30 minutes. Incidentally, that battery pack has as much energy as 100mL of gasoline, which is why gasoline-powered…
My point of reference I use to imagine energy is a major league baseball player hits a baseball with 1,234 J.
1KW/h is 3,600,000 J.
Given how popular (and damn near impossible to discern) unsafe and unprotected lithium-ion batteries are, the idea of making a homegrown power wall terrifies me in ways I can't even begin to contemplate. An 18650 battery, if combusted, can produce hydrofluoric acid with just water vapor in the air (or the water in your lungs) if they use lithium hexafluorophosphate as the electrolyte. Hydrofluoric acid can and will c…
http://www.brandforsk.se/MediaBinaryLoader.axd?MediaArchive_...
The relevant datapoint is on page 61:
"As seen the yields of HF is much lower for the lap top cells, in fact the HF detected online was below the determined detection limit."
The graphs on page 101 also show HF concentrations below 4ppm --- and keep in mind this is basically all of the gases collected from the burning pack. Looking at the safety data for HF, the permissible exposure limit is only slightly lower at 3ppm and it's immediately dangerous at 30ppm.
In other words, it would be a bad idea to deliberately concentrate and inhale the fumes of a burning cell, but the HF probably isn't going to kill you. Some good ventilation of the area should be sufficient.