How old are the batteries? Do you own your battery? What is a battery worth? Do you load your truck with aging, unreliable batteries to swap-off with other aging, unreliable batteries?

When it comes to a truck which will have a sizeable number of large batteries, you're pretty much statistically guaranteed to never have more than a dud or two so long as the battery management process is sound.

As a service station manager, how do you test each of these batteries to ensure its safety and reliability (its level of aging)

By, for example, any of the dozen or so methods already used for this purpose?

As a service station manager, how do you offset the cost of rotating out old batteries traded in by truckers?

By rolling that into the swapping cost?

Could you please ask questions a little harder than "What does 1+1 equal?" I'm seriously not getting why you don't already know the answer to these questions you're asking.

Changing batteries in something like a truck is a labor-intensive process.

Wait a minute, you think that when people talk about battery swap they're talking about someone going up and swapping batteries by hand?

mounting may preclude a fast removal operation.

Many companies have already demonstrated battery swap for cars, which is a far harder target than trucks. With trucks, my preferred mounting is on the trailers themselves (with the cab having its own, non-swappable batteries). You already have, today, stuff mounted to the underside of trailers. It's right where the structural strength is already located and you have tons of open space underneath for easy access and standard form factors. It's an order of magnitude easier challenge than for cars, which you practically have to have disassemble their frames to get their batteries out.

The operation may take 40 minutes overall

Battery swap in the much harder case of cars can be done in less than a tenth that time.

Mounting the batteries affects balance, thus handling, thus safety

And you're envisioning that one would load all of the batteries only on one side or something...?

Think about it as if you were going to swap an entire, pre-filled gas tank

And think about having the tank you plan to switch out be a standardized external tank mounted in a standard form factor on a standard trailer.

Assuming an overall pack energy density of 200 Wh/kg, 1kWh would weigh 5kg. A typical truck may move around 1 tonne 120 miles per gallon of diesel. A gallon of diesel contains about 10kWh of energy. An electric motor will use it about 2,5 times more efficiently than a diesel ICE, so 120 miles per gallon of diesel equates to 300 miles per 10kWh of electricty, or 30 miles per kWh electric, or 30 miles per 5kg of battery pack. So every 30 miles of range you want takes up 0,5% of your cargo mass. If you want say 300 miles range then it would consume 5% of your payload.

On the other hand, the price difference in the cost of fuelling the truck (diesel vs. electricity) would be massive. For each tonne of cargo (assuming 300 miles vehicle range and an average haul distance per hour of say 60 miles), giving up 50kg of cargo to enable to you spend $0,30 on electricity ($0,10/kWh) instead of about $1,80 on diesel ($2,70/gal), or a savings of $1,5 for giving up 50kg of cargo. If we scale to say 50 tonnes of cargo then this equates to giving up 2,5 tonnes (5%) of your cargo to save $75 per hour.

There have been electric delivery trucks for a long time - for example, Smith Electric Vehicles has been making li-ion trucks almost as long as Tesla has been around. And they follow up on a long history of electric delivery vehicles on a continuous line dating back to the early lead-acid days. But "existing" doesn't mean "having blown the market wide open". The big question is when that could happen.

You know, though, as ridiculous as it sounds, I almost wonder Tesla's efforts could evolve into a killer delivery vehicle. The Model S / Model X drivetrain is already starting to get into the power range of a big rig, and big rig budgets can afford their high prices. Combine that this potential solution to charging over long distances and you really could have a winner.

I wouldn't count on really powerful fast chargers ever getting really cheap. Cheaper than they are now, sure, but just ignoring all of the communication and high power conversion hardware you still have to have:

1) A powerful cooling system in your charger (for a really powerful connection, you even need to liquid-cool the charging cable)
2) A huge amount of copper (or aluminum, but that comes with a number of additional challenges) in your charger
3) A high power feed installed to your location
4) A high capacity and high power battery buffer to even out your charges if you want really fast charges / fast charges for big packs (say, 250+ kW)
5) A professional electrician to do the installs (and remember, we're not talking about home wiring here, we're talking about huge-current high-voltage connections). ... and so forth. These things will always add up. So maybe we'd not be talking about $100k to add one.... but I'd be shocked if even in mass production they could be manufactured, delivered and installed for under $10k. Probably several tens of thousands of USD per unit.

Where I live, it's a one. Check my photos out.

Turning off lights in cities isn't going to help astronomers much.

Actually, no. City glow is a huge impediment to astronomy for an area hundreds of times the size of the city.

There's a middle ground here. Lighting can be designed so it primarily lights the ground, instead of going every which way. Goes a long way towards reducing problems optical telescope use faces.

Also some moderately recent styles for t-shirts. And hosiery. And.... jeans.

It appears that giving someone scissors is a direct route to dolling out cuts. :)

Short range wireless audio/video is still going to have a lot of the same issues in terms of quality and latency. Some solutions will do lossless video over short distances (the 60GHz wireless video stuff for example), although I'm not sure about latency.

What are you actually looking to put on the TV, though? If it's just media playback, there are lots of solutions involving either dedicated media players or HTPCs that are going to provide a much smoother user experience than how you describe using the laptop (they'll play stuff over your wireless network). If it's videogames, then there are solutions for that too, various in-home streaming options such as those provided by nVidia or Valve that can stream from your desktop computer upstairs to a cheap dedicated device (like an nVidia Shield or a Valve Steam Link, which will be out in November for $50). Those are not lossless, but the quality is decent, and since they're gaming focused, the latency is pretty low. They're designed to use a gamepad with them, though.

So maybe something that is more specific to your use case might work better. Some of them (like the nVidia Shield) could be used for both media and gaming. I think SteamLink is gaming specific, it's pretty optimized for that one task and nothing else, hence the low cost.

I'm not sure that I'd trust a passive 50ft HDMI run to do 1080p60, even at 26AWG... and 26AWG cables aren't exactly slim. If I needed to run 50+ feet, I'd use an active cable (like a monoprice redmere one) or some sort of Cat 6 based extender. The Redmere cable if you want something simple, the Cat 6 extender if you want something cheap (redmere cables are around a buck a foot).

Bonus to using Cat 6 is that it's easy to extend USB over Cat 6 too, so if you just run three Cat 6 cables, you can use cheap passive extenders for both HDMI and USB with a cheap USB hub for the keyboard/mouse.

You may be looking at two different solutions, then. One to handle the audio and video, one to handle the keyboard/mouse.

Does it absolutely need to be wireless? Both HDMI and USB are easy to run over ethernet cabling with pretty cheap passive adapters, and it's the only solution that isn't going to have any sort of lag or quality loss. $12 adapters get you 150ft over ethernet cabling for USB, $20 gets you HDMI over 98 feet of ethernet cabling, and there are active solutions if you need to get HDMI farther. Drill some holes between each floor and hide the cable and that should work for you. Note that these don't use a network for extending, they use the ethernet cabling directly.

If it does need to be wireless, it's not going to be cheap, it's not going to be lossless, and it's not going to be low latency. There are various solutions, like WHDI transmitters (~30 feet through walls, maybe $170 for a kit), or h.264 transmitters (~60 feet through walls, maybe $500 for a kit). You may also be able to combined the h.264 transmitters with a powerline network to get more range (the ones that I have do wireless or ethernet, since they use UDP/IP). Both will add latency and reduce quality slightly.

USB is trickier, as wireless USB extenders are VERY rare. The few that I could find had all been discontinued, so the only option might be enterprise-grade USB-over-IP extenders that might work over wifi adapters (they're not tested over wifi).

Really, just drill some holes and run some Cat6 cable with some cheap Monoprice HDMI-to-Cat6 and USB-to-Cat6 passive adapters. This will save you hundreds (or thousands) of dollars as compared to wireless gear that will always be a really crummy experience.

Whoever said that the electricity was free? It's the charging that's free, because they treat the cost of the estimated lifetime energy consumption of your car to be a sunk cost as part of the purchase. You've already paid for the electricity.

Tesla eventually intends to have their charging stations be completely solar powered. I'm not convinced that's actually feasible, but if it were, then the cost of electricity would be eliminated, and the remaining cost would be the construction and maintenance of the charging stations.

There are 217 stations in the US, not 100. They're still rapidly expanding.

The numbers are also not comparable. Gas stations are required for all refuelling of gasoline-powered vehicles. Supercharger stations are only required for long-distance trips that are typically quite rare. There are often many gas stations in close proximity to eachother, sometimes two or three at the same intersection. That may be useful when there are different gas stations competing with eachother, but pointless when you're talking about a manufacturer-provided charging network that is free to use.

I wouldn't be surprised if they could get some more specific clues on what water it's been in - for example, marine growth species types or isotopic ratios - to help pin it down better than just general drift calculations (lots of places could dump debris on Réunion). There are could also be potential clues on how much sun or what temperatures it's been exposed to, such as rates of plastic degradation, and perhaps that might also help give them better ideas of what areas it's been in based on weather patterns since the flight was lost.

There are so many potential clues... each one rather vague on its own, but all together, I imagine they'll get pointed in the right direction.

Re-read the text right before what you'r replying to. Block-sized inserts. If you shift all the data by exactly one block, then the blocks would be the same.

Pee at an angle to the wall.

Steve Jobs: "You're holding your wanker wrong".