Regarding the safety of EV's and their batteries, there is no real safety advantage between Cylindrical and Prismatic packs. Cylindrical have some minor cooling advantages, but getting the same power density as prismatic packs is difficult. Mechanical strength is important, but the electronic monitoring will react well before any mechanical component has failed. The batteries are monitored (voltage, current, Charge state, State of Health and temperature) on the cell pack level, so even if a single cell shorted, the system will react in microseconds and like any ICE vehicle, the entire power source is also cut as soon as any crash is detected.
As for the driving experience, as mentioned above, it's the torque curve that people notice at first. People are used to an engine needing time to react, especially if they drove a diesel up to then. The motor definitely isn't an ON/OFF situation, it's just like any variable motor control.
I won't comment on the environmental or infrastructure aspect, that's politics not engineering and will be different for every country.
McBryce.
* This information/opinion doesn't come from a report, I've worked in EV and EV Battery development for almost 20 years, including work on the Prius.
This is how to pack a delicate piece of TEA gear for shipment. These photos are of the outer carton, the actual packing and the meter itself and its first power up, later I'll tear it down and snap some more pics, I;m excited, have never seen inside one of these before, and I'm wondering if has any similarities to the 4503 and the 1905A, one thing I can say is that when compared to the TTI counters and function generators, this 1906 is heavy, it as heavy as my HP3466A meter and that even has a SLA battery inside, so my fears of it wandering over the bench while being used were totally unfounded.
At least only minimal Test gear was used. Kind of cool but wow on the $ even with the level of work eBay auction: #274391389907
This is how to pack a delicate piece of TEA gear for shipment. These photos are of the outer carton, the actual packing and the meter itself and its first power up, later I'll tear it down and snap some more pics, I;m excited, have never seen inside one of these before, and I'm wondering if has any similarities to the 4503 and the 1905A, one thing I can say is that when compared to the TTI counters and function generators, this 1906 is heavy, it as heavy as my HP3466A meter and that even has a SLA battery inside, so my fears of it wandering over the bench while being used were totally unfounded.
Same reason we pack dynamite into cylindrical sticks, and we consider a brick of C-4 in a box much more dangerous than an equivalent capacity of dynamite stored appropriately.
Are you suggesting that the individual who sent me this was remiss in their packaging? (That is LITERALLY how it was packaged, and what I saw when I opened the box.)
Fortunately it is light weight and arrived in good nick.
-Pat
This is how to pack a delicate piece of TEA gear for shipment. These photos are of the outer carton, the actual packing and the meter itself and its first power up, later I'll tear it down and snap some more pics, I;m excited, have never seen inside one of these before, and I'm wondering if has any similarities to the 4503 and the 1905A, one thing I can say is that when compared to the TTI counters and function generators, this 1906 is heavy, it as heavy as my HP3466A meter and that even has a SLA battery inside, so my fears of it wandering over the bench while being used were totally unfounded.
That’s a bloody miracle for CDL who shipped me a Tek 475 loose in a box. I’m impressed.
I think they just hate me .
How's the continuity on it? I understand it's shit but never actually tried it myself. Rest of the meter is good though
Same reason we pack dynamite into cylindrical sticks, and we consider a brick of C-4 in a box much more dangerous than an equivalent capacity of dynamite stored appropriately.
Erm, no we don't. Those of us who have held explosives licenses know that of two energetically equivalent quantities of C4 and dynamite, the dynamite is by far the more dangerous. I would cheerfully hit a slab of C4 with a hammer, I would happily set light to it with a match, in theory I would happily shoot it (there are limits to my faith in what I know in theory is true when it comes to high order explosions). I would most emphatically not do any of the same to a stick of dynamite unless I wanted to die.
I think they just hate me .
How's the continuity on it? I understand it's shit but never actually tried it myself. Rest of the meter is good though
Okay... thinking aboot it, the C4 is probably a bad analogy, considering different chemistry, and my point was aboot packaging. Hmmm...
Okay... how aboot this. Grossly simplified, dynamite is nitroglycerine repackaged to A) make it more stable and B) to make the amount of explosive potential per package smaller and more predictable by dilution.
Similarly, cylindrical Li-xx cells are by nature more capable of keeping their integrity under pressure due to shape and size, and B) by individually encasing a smaller amount of lithium electrolyte material per cell, the likelihood of similar mass of electrolyte becoming involved is less.
Yes, I know that prismatic cells are supposedly chamber-isolated, but as videos we've seen demonstrate, that is not nearly as effective in a catastrophic short-circuit condition.
Does that comparison make more sense?
Okay... so here is my question to you old friend... as I know you know the chemistry better than I do:
How much of the difference in chemistry between Nitroglycerine/Dynamite is really different chemistry, vs just being able to make a higher concentration of the nitrate explosive (terminology...?) "stable" in a given amount of "filler" material, whether colloid or powdered cellulose...?
Nitroglycerine is still the same family of explosive, is it not?
mnem
There is a 3v Lithium 20mm button cell that retains the cal data and as this meter was made in 1997, I suspect that the cell needs replacing, and they stuck it in vertically, right beneath the IEC mains inlet and its boot.
Same reason we pack dynamite into cylindrical sticks, and we consider a brick of C-4 in a box much more dangerous than an equivalent capacity of dynamite stored appropriately.
Erm, no we don't. Those of us who have held explosives licenses know that of two energetically equivalent quantities of C4 and dynamite, the dynamite is by far the more dangerous. I would cheerfully hit a slab of C4 with a hammer, I would happily set light to it with a match, in theory I would happily shoot it (there are limits to my faith in what I know in theory is true when it comes to high order explosions). I would most emphatically not do any of the same to a stick of dynamite unless I wanted to die.
Okay... thinking aboot it, the C4 is probably a bad analogy, considering different chemistry, and my point was aboot packaging. Hmmm...
Okay... how aboot this. Grossly simplified, dynamite is nitroglycerine repackaged to A) make it more stable and B) to make the amount of explosive potential per package smaller and more predictable by dilution.
Similarly, cylindrical Li-xx cells are by nature more capable of keeping their integrity under pressure due to shape and size, and B) by individually encasing a smaller amount of lithium electrolyte material per cell, the likelihood of similar mass of electrolyte becoming involved is less.
Yes, I know that prismatic cells are supposedly chamber-isolated, but as videos we've seen demonstrate, that is not nearly as effective in a catastrophic short-circuit condition.
Does that comparison make more sense?
Okay... so here is my question to you old friend... as I know you know the chemistry better than I do:
How much of the difference in chemistry between Nitroglycerine/Dynamite is really different chemistry, vs just being able to make a higher concentration of the nitrate explosive (terminology...?) "stable" in a given amount of "filler" material, whether colloid or powdered cellulose...?
Nitroglycerine is still the same family of explosive, is it not?
mnem
Okay... thinking aboot it, the C4 is probably a bad analogy, considering different chemistry, and my point was aboot packaging. Hmmm...
Okay... how aboot this. Grossly simplified, dynamite is nitroglycerine repackaged to A) make it more stable and B) to make the amount of explosive potential per package smaller and more predictable by dilution.
Similarly, cylindrical Li-xx cells are by nature more capable of keeping their integrity under pressure due to shape and size, and B) by individually encasing a smaller amount of lithium electrolyte material per cell, the likelihood of similar mass of electrolyte becoming involved is less.
Yes, I know that prismatic cells are supposedly chamber-isolated, but as videos we've seen demonstrate, that is not nearly as effective in a catastrophic short-circuit condition.
Does that comparison make more sense?
Okay... so here is my question to you old friend... as I know you know the chemistry better than I do:
How much of the difference in chemistry between Nitroglycerine/Dynamite is really different chemistry, vs just being able to make a higher concentration of the nitrate explosive (terminology...?) "stable" in a given amount of "filler" material, whether colloid or powdered cellulose...?
Nitroglycerine is still the same family of explosive, is it not?
mnem
Standard petrol (or gasoline to our cousins on the other side of the pool) has 31.5MJoules of energy per litre, that's 8.7kW/hrs in just one litre. Factors higher than the best battery on the market and we drive around with 40 to 50 litres of it in a glorified bucket every day. If safety didin't bother us up to now, why should it now?
McBryce.
Okay... thinking aboot it, the C4 is probably a bad analogy, considering different chemistry, and my point was aboot packaging. Hmmm...
Okay... how aboot this. Grossly simplified, dynamite is nitroglycerine repackaged to A) make it more stable and B) to make the amount of explosive potential per package smaller and more predictable by dilution.
Similarly, cylindrical Li-xx cells are by nature more capable of keeping their integrity under pressure due to shape and size, and B) by individually encasing a smaller amount of lithium electrolyte material per cell, the likelihood of similar mass of electrolyte becoming involved is less.
Yes, I know that prismatic cells are supposedly chamber-isolated, but as videos we've seen demonstrate, that is not nearly as effective in a catastrophic short-circuit condition.
Does that comparison make more sense?
Okay... so here is my question to you old friend... as I know you know the chemistry better than I do:
How much of the difference in chemistry between Nitroglycerine/Dynamite is really different chemistry, vs just being able to make a higher concentration of the nitrate explosive (terminology...?) "stable" in a given amount of "filler" material, whether colloid or powdered cellulose...?
Nitroglycerine is still the same family of explosive, is it not?
mnem
Dynamite* is just nitroglycerin adsorbed or absorbed into some inert material to make it safer to handle - originally Kieselgur, a siliceous earth not unlike the Fuller's Earth we're all familiar with from cat litter. It's just a mixture, there's no change in chemistry; indeed the inertness of the ad/absorbent is necessary, historical versions have used wood meal to disastrous consequences as it's not strictly inert. The packaging is typically waxed paper, it facilitates handling and keeps water out and that's about it. Certainly the packaging into sticks offers no protection against explosion - if one stick detonated in a room every stick in the room would be detonated by that, even if yards apart. Nasty stuff and in the modern world it's obsolete as an explosive - there might be some edge use cases for it but if there are I don't know of them.
* There have been some bastard cousins going under the name of "Dynamite" such as 'military dynamite' which is basically RDX. But Dynamite per se gets all its explosive power from nitroglycerin.