To support a 48 hour recharge of the battery hypothesized upthread, you would only need to scale up this system by about 10x. Or attach 10 along the length of the ship. Or some combination of those options.
This is a non-problem.
Edit: Excuse me, but I misread the brochure. The existing system need be only scaled up by a factor of 2.5x to recharge a container ship in 48 hours.
> I’ve only asked a small number of contractors, but every one I’ve asked wished they could buy a smaller, lower, practical work truck with decent capacity
And if you ask Reddit, everyone says they want to buy a brown NA station wagon with a manual... yet nobody actually buys those cars when dealers stock them. This is what economists call "stated" vs. "revealed" preference.
Nissan discontinued the last small long bed, small-cab compact pickup last year. Now you can only get it as a two row. They had a monopoly on this supposedly lucrative market segment that contractors claim to want... yet it was discontinued because nobody was actually purchasing that configuration.
Even for full-size pickups, GM revealed less than 10% of the product mix is single-row long bed.
It's not some conspiracy. People. Aren't. Buying. Them.
I have no info on Tesla batteries. But, just as a point of reference, you can now buy knock-down 48V battery "kits" from China for under $90/kWh. They include everything you need: case, cells, BMS, circuit breaker/isolator, and fire suppression. Assembly takes about an hour. (The raw prismatic cells without the rest go for ~$50/kWh).
Shipping from China to the west coast runs an additional $30/kWh due to the weight of the cells and volume of the box (shipped in several boxes to reduce cost). So you can have a 300 lbs, 15 kWh 48V battery shipped to your door for about $120/kWh).
High voltage EV batteries need additional components (like HV contractors) due to stacking so many cells in series, but it seems entirely plausible that Tesla's economies of scale allow them to offer a 75 kWh battery for $10k (~$133/kWh) plus installation.
The app notes and data sheets of related parts suggest that the target application is large conversion ratios, where the duty cycle in an inductive converter is close to 0 (or 1). That forces tradeoffs, like a lower switching frequency (lower efficiency), a larger inductor (more weight and/or cost) or very short T_on for one of the FETs (lower efficiency because transition times become important). So you can use the charge pump as the first stage of a hybrid converter to get a higher system efficiency.
My recommendation to anyone who finds themself stuck in this corner of the design space is to consider a tapped inductor converter.
I did a tapped inductor boost last year to take 3V input to 80V output (at not-much output current, I forget exactly what it was but it was mostly a bias voltage; also, the actual output voltage was DAC-set and could be quite low, so the loop dynamics were unpleasant). It was definitely annoying to wrap my head around, and very annoying to select the inductor (Würth has a nice OTS series, at the usual Würth prices; HVM would likely want a custom or semicustom design) but it just plain worked the first try and continued working through the usual stress tests and also the unusual stress tests of the Very Expensive Load™ getting itself Very Expensively Killed™ (for non-power-supply reasons). I was really happy with that converter, that kind of step-up ratio isn't easy and it just worked.
My refs were written into the schematic so I dug it up and might as well post the whole thing (SEE WARNINGS BELOW): https://i.ibb.co/zVXZWxHg/tapped-boost.png (forgive me, I have no idea on the state of image hosting in 2025 so I hope that link holds up)
I misremembered what design I actually ended up building. It was nominal 5V to 75V but was tested at a wider range (including the mentioned 3V to 80V). The variable voltage was implemented later, in a linear stage, which did in fact have a number of issues.
ADI app note AN-1126 was very helpful in this design. It pushes for a different topology, yet compares with this one and others in some detail. Its arguments against tapped inductor designs are threefold: (1) sometimes EMI issues on the switching node (fair, and a real concern, but not interesting for what I needed to do), (2) the inductor is annoying to source (very true), and (3) the main technical objection is that demands on the output rectifier are high and might require you to use something crappier than a Schottky. That last one is true in general but for this design in this decade, I was comfortably within medium voltage Schottky territory, and so their main objection was a complete nonissue. That looked good to me so I went ahead and built it, and was not disappointed.
The inductor was 744889030330 (say that three times fast) from the WE-MTCI family which worked a dream. I don't remember why this exact switcher chip was chosen but I do remember having a lot of candidates and so the choice was kind of arbitrary. The control scheme type it uses is important, though. I don't think the zener did anything but being paranoid I wanted to have the footprint there for the prototype build rather than not have it.
THE PREVIOUSLY PROMISED WARNINGS WHICH ARE ACTUALLY REALLY IMPORTANT SO I AM USING CAPS:
1. 80V can kill you. Really, it can. Use caution!
2. This is the design I sent off for fab (and perhaps not even the final version, if the folder notes are any guide). It is not the redlined, working version. I believe this stage was OK. Maybe it needed a bit more output capacitance? Certainly I know the following stage, not shown here, had severe issues (most of them stupid and obvious once noticed). So treat this as good inspiration, not ground truth.
3. Did I mention that 80V can kill you? USE CAUTION.
Thanks for the refs and discussion--especially that app note.
I will note that we're all talking about 10+ year old chips and technology--mostly prior to GaN.
Apparently, I'm going to have to dig through a bunch of stuff to see what is current. While the topologies don't change, the tradeoffs between them do as technology changes.
Edit: Stare at the LT7890/1/2/3 series for GaN stuff by way of comparison
GaN is not appropriate for most use cases. It matters when high frequency matters, which is usually when magnetics size matters. I have also seen it used very well for ultra-low input voltages (basically energy harvesting).
It is also uncompromising and brutally difficult to get working well. GaN-FETs love to commit suicide in new and entertaining ways. And LTC7890 is not something I would want to implement in any design (though of course I'd suck it up and do it if it was the right choice).
99% of the market is traditional boring stuff because 99% of the market is well served by traditional boring stuff.
I expect less than 10. Once you drive an EV, every big noisy diesel feels impotent and gutless. Kind of like a small yappy dog that’s all bark and no bite. There’s just nothing like the zero-lag gut-punching acceleration of an EV.
The industry is trying their best to fight against it. The EU is currently planning to ban new ICE cars from 2035, but the conservative German government & car lobbyists are trying to get them to drop those plans... That, combined with high tariffs for cheap asian EVs will probably artificially keep us on ICEs for a while longer.
Unfortunately it's not really up to us plebs, it's up to the rich and powerful, who have every incentive in the world to continue fossil fuel use.
Trump has outright said he's pro fossil fuels and his policy choice shows it. If there was a proposal to ban or limit EVs in the US, I would not at all be surprised. These people do not care about you or me or all, just their pocket linings.
Slow moving traffic at one intersection and free flowing traffic at another could easily account for a 10x ratio of particulate pollution, especially in European capitals where diesels are prevalent.
But a 10x ratio on the same road is also plausible if the Google car is following a large truck on one pass and then driving by itself on the second.
For the Russian invasion of Ukraine, that may have had more to do with Ukraine’s budget and economy of the time: Ukraine had a massive trade deficit with Russia in the 2000’s and early 2010’s, and the government was running a huge deficit.
Faced with cuts to state pensions, Ukraine started using gas from the pipeline which connects Russia to Western Europe, without paying for it. That understandably annoyed Russia (that’s not a justification for war!), who couldn’t turn off gas to Ukraine without also turning it off for their main customers in Western Europe.
These events seemed to have kicked off the norstream pipeline (legal) and invasion of Crimea (illegal).
The pipeline thing may have annoyed Russia, but it was the Maidan revolution which resulted in the invasion of Crimea. Russia simply doesn't like having neighbours that aren't its puppets. When Ukrainians got rid of Yanukovych, Ukraine stopped being a Russian puppet, which annoyed Putin very much.
Russia has a long, long history of being mean to its neighbours that choose to pursue independent policy. As an example, Finland and Baltic states have been subject to countless of intentional airspace violations since the collapse of the Soviet Union, even before the Ukrainian war.
My belief was that many analysts at the time considered that the justification rather than the cause, as alluded to by the Ukraine counter claims in the guardian article.
Similarly, Trump isn't saying he wants to invade Venezuela to distract from domestic issues, but it's all about the "drug boats".
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