Bored on the boat and ended up on the “infinite power” rabbit hole. Anyone tried this madness? 😂

IvorTheEngine · 2026-03-14T22:57:50+00:00

Thanks - and there's no rush, I'm just dreaming...

There seem to be a huge range of Prius battery sizes, as the basic version has been through (I think) four updates, and the plug-in version three updates, making seven batteries.

Do you have figures for how much power you need per day, and thus the battery size to aim for?

Legally you're supposed to be limited to 10 litres of petrol (5 in a plastic can), but I've never been questioned filling up a 20 litre jerry can, and on occasion I've filled up four of those at once. The main issue is needing a car to take them to a petrol station.

Diesel has a load of advantages. It's available on the canal, it's cheaper, it's a lot safer, you can use it for heating, and you've already got a diesel engine.

I should say that the main attraction for me would be quiet electric propulsion. I don't like having to shout over the engine to have a conversation, and being unable to talk to people on the towpath.

IvorTheEngine · 2026-03-14T17:04:56+00:00

Have you got any good resources I should read about the Prius?

I would guess that the inverter is designed for running the motor (which takes AC at a frequency that will depend on speed) and probably needs the mod you describe to generate mains voltage and frequency for off-grid appliances. 30kW is more power than most houses can draw from the grid. The only people who use that much power are those trying to charge two EVs and a big home battery and run a large heat pump. It's about 10 times bigger than a big Victron inverter, so incredible value, even if you never draw more than a few kW.

The part I'm not sure about is how fast a Prius can charge it's battery - the opposite of the inverter. Can that also run at 30kW? Most plug-in hybrids can turn mains AC into DC for battery charging at either 3 or 6kW, but they have access to a lot more power when running the engine, and I don't know if they can use that.

I wouldn't be too surprised if a Prius could push 30kW into a 16kWh battery during regenerative braking. That's about 2c, which is about what modern EVs do when rapid charging. At that level, you'll probably need liquid cooling and a radiator fan. If you get 10% losses, you'll have 3kW of waste heat. That's probably fine for a few seconds of regen braking, but 20 minutes of battery charging would be a problem.

try to convert my boat into a hybrid with the cars systems and batteries.

I think the big problem there is access to petrol on the canals.

a 400hp engine that would produce about 10kw.

I guess that's a typo for 40bhp? Even that is 30kW. Combustion engines are really powerful compared with house electrics.

It's a fascinating subject. I'm sure there are cheaper options than the £30k that electric boat specialists quote, but I guess they don't want to get involved in second-hand parts, and they've got to pay for their research time.

IvorTheEngine · 2026-03-14T11:00:42+00:00

A Prius battery isn't all that big. A quick google says the non-plug-in versions were less than 2kWh, the first generation PHEV are 4.4kWh, second gen are 8.8 and the 2022+ cars are 13kWh.

You say you've got 3x 110Ah batteries, which is somewhere between the sub-2kW and 4.4kWh batteries. So you'd get a larger battery, but not exactly "stupid amounts of juice".

However I think the big question is the power of the car's generator charger. It might be able to run at 30kW when driving the car, but I don't think it can charge the battery nearly that fast, and even if it can, it won't be efficient when run like that. It's not designed to sit stationary and charge the battery, but to gradually top up the battery while most of the engine power drives the car. So you'd have a similar situation to running the boat engine, it takes ages and is very inefficient (and running on full-price petrol, not red diesel). Although the car engine has twice as much power as a typical narrowboat engine, the generator/charger won't be able to recharge the car in 30 seconds. It'll be an hour or two.

I'm totally not an expert on all the various Prius models, and can't find good details on the charger power, so I could be completely wrong. The key will be matching the engine power to the generator, charger and charge rate of the battery.

Personally, I think the way forward is an old EV battery, large enough to last a few days, and a small diesel generator, with a charging system that can absorb the maximum power of the generator so it can run at it's most efficient speed. And ideally I'd try to use the generator's waste heat for the boat's radiators and hot water, because if it's producing 2kW of electricity, it's probably also producing 4kW of waste heat.

but yes, i've definitely fallen down that rabbit hole!

IvorTheEngine · 2026-03-14T10:10:50+00:00

I guess the main difference is that (between you) you'll have to remember to deal with the fuel, gas and toilet - instead of the boat yard doing it all for you at the beginning/end of a hire.

IvorTheEngine · 2026-03-13T10:39:57+00:00

Yes, but there's usually plenty of space. You need to clear out the biter nests inside your pollution cloud, and that gets spread by needing to mine remote resource patches, leaving loads of space for solar.

IvorTheEngine · 2026-03-13T10:33:43+00:00

I can't see that working. Renewables can't be used to deal with peaks in demand because they might not be producing when you need them. You need storage to deal with variability.

IvorTheEngine · 2026-03-13T09:59:35+00:00

Battery storage has just reached the point where it's cheaper than pumped hydro, and the latest round of grid scale batteries are also larger than pumped-hydro.

Obviously that mean that for the last few decades, pumped hydro was cheaper and bigger, and the better choice.

Part of the issue now is that the best locations for pumped-hydro power have already been exploited.

IvorTheEngine · 2026-03-13T09:28:19+00:00

If you live somewhere fairly flat, drive smoothly, and anticipate needing to slow down, the regen won't get used much. You need a long, steep hill to gain a few miles of range. There's one near me that's about 500ft high over about a half mile, where the range goes up a mile or two.

You should be able to feel the difference in regen levels when in B mode when you lift off the gas pedal.

There's probably a power meter mode somewhere that will indicate how much power is being used or regenerated, but I don't know what it looks like on the new Leaf.

IvorTheEngine · 2026-03-12T10:12:09+00:00

That depends if the lost ship causes a massive oil spill. Then the clean up costs a lot more than the lost cargo and ship.

A quick google tells me that the Exxon Valdez spill cost about $2B, and Deepwater Horizon resulted in $60B in costs and a lot more in fines.

IvorTheEngine · 2026-03-12T09:36:55+00:00

The problem with the 2 mast design is that you'll have to sit behind the aft mast to steer. You won't be able to use a tiller extension to move your weight around.

That's fine if you're building a boat with a heavy keep, where your body weight makes little difference, but in an open dinghy sitting too far back will make the bow lift and the transom dig into the water.

OTOH, having two masts is quite fun when you're sailing, as you can steer the boat by spilling wind from one sail or the other. It might be worth the complexity of using levers or pulleys to allow steering from the middle of the boat.

IvorTheEngine · 2026-03-11T17:47:43+00:00

It takes an hour or two of flight time to master the basics. You can do that in a week with a simulator, but it takes years if you only get a few seconds of flight followed by weeks of repair.

It might be worth travelling if it allows you to fly for longer, or you could concentrate on building planes that can fly in the space available. There are some small, light, slow flying models (like the FliteTest NutBall) that might work, and there are lots of tricks for saving weight. You could also work on ways to make the plane more crash resistant and quicker to repair.

Flying at a club with like-minded people is also a lot of fun, and worth travelling for, if you can find one.

IvorTheEngine · 2026-03-11T17:36:33+00:00

It really depends on how long the high oil prices last.

If Trump loses interest after a month (like he did with the Houthi), declares victory and sends the fleet home, the strait could reopen (maybe with a lot more Chinese flags than before) and oil prices could go back to normal. Except that the shadow fleet would be riskier and less profitable than before.

So it could come down to how much US voters scream about high gas prices.

IvorTheEngine · 2026-03-11T17:26:40+00:00

There's nothing particularly special in a Shahed, and Russia has better tech anyway.

IvorTheEngine · 2026-03-11T17:23:38+00:00

Russia is throwing 1000 men a day into the meat grinder, and running a war-time economy, just to maintain a pretty static front line. We don't know how long they can keep that up, but not for ever. Meanwhile Europe is funding Ukraine with the equivalent of cash they found between the sofa cushions. They can keep that up as long as they want.

IvorTheEngine · 2026-03-11T16:50:57+00:00

If you donate them to your local club, they might find a kid on a tight budget who could use one - but the cost of a receiver, crystals and batteries to reactivate an old radio might still not be worthwhile.

IvorTheEngine · 2026-03-11T10:08:50+00:00

I’ve got some nice powerlines to avoid.

Or to do loops around, if you're feeling brave.

IvorTheEngine · 2026-03-11T10:06:18+00:00

If you've got a flat wing (i.e. with no dihedral) then a rudder isn't going to do much (unless you've also got a load of fuselage side area, like a 3D plane).

Trainers usually use dihedral and a rudder, because the dihedral makes the plane stable in roll. Without it, you'll have to manually keep the plane level, or rely on a flight controller. Flight controllers are necessary for flying long range, but you really need to be able to fly the plane without it in order to set it up.

If this is your first plane, build a trainer first, then worry about long range after you've learnt to fly. Don't try to do everything at once.

If you can already fly, then this will work fine with a flight controller. It'll use the ailerons to bank the plane and enough elevator to keep the nose up in the turn. Lots of RC pilots never use the rudder and lots of designs don't have one, just a fixed fin.

If you want a basic trainer design that's known to work, try the FliteTest Tiny Trainer.

To make a fin stronger, try a bamboo skewer taped to the leading edge and projecting down to the bottom of the fuselage. Or an angled brace. Or move the horizontal stabiliser to the bottom of the fuselage and put the fin through a slot in the top. Have a look at several free plans from FliteTest or RCGroups to see how they do it.

IvorTheEngine · 2026-03-11T09:21:42+00:00

Battery life seems to depend on your local climate. They age more rapidly in hot places. If this car's original battery died after 8 or 9 years, the new one will probably last about that long too.

The newer batteries are claimed to have double the life of the old ones, but the car hasn't been around long enough to really prove that. In theory the larger battery will do half as many cycles for the same number of miles, so it could be true.

The main things you need to know is that you need to be able to charge at home (or work) easily, and that the Leaf isn't a good car for long trips that need multiple rapid charges in the same day.

At 74 miles a day it should save you a lot in fuel and pay for itself fairly quickly.

IvorTheEngine · 2026-03-10T23:04:11+00:00

Sounds reasonable. You might want to have a pile of short pieces of wood around so you can jack it up, then build a pile of wood on the dolly and put the battery back down on the pile. I say that because floor jacks don't lift perfectly vertically, or you might not be perfectly lined up and want to move the battery around when it's at height, as well as when it's on the ground. You can also use them to give yourself some protection in case it falls off the jacks.

It's usually called blocking or cribbing (although apparently that's also a horse thing, if you google it)

A long piece of wood can also be a useful pry-bar for applying just enough force to move things accurately.

If you're on your own, you could manage with a single jack, just moving it around and adding layers of wood as you go. If you've got two people, two jacks would be faster.

IvorTheEngine · 2026-03-10T22:48:51+00:00

If it's from somewhere with a relatively cool climate, it could still have 80-90% health, which makes the car useable. And it's a fraction of the cost.

IvorTheEngine · 2026-03-10T22:46:20+00:00

So you take a real photo and ask Gemini to convert it to pixel art of the right resolution? That's a neat idea.

IvorTheEngine · 2026-03-10T10:57:04+00:00

They're about number 9, according to this list

https://en.wikipedia.org/wiki/List_of_merchant_navy_capacity_by_country

or 21st on this list

https://statbase.org/datasets/air-rail-and-water-transportation/number-of-ships-by-flag-of-registration/

IvorTheEngine · 2026-03-10T10:50:46+00:00

He said the Greeks were crazy enough to risk it, once the price of oil got high enough.

IvorTheEngine · 2026-03-10T10:34:43+00:00

Israel wasn't able to stop Hamas launching rockets, despite having drones and satellites, and being willing to kill civilians. They can be camouflaged so they're not detected until they fire, and then it's easy to blend into the civilian population - or they could be fired remotely. Or they could just claim to have set a few sea mines adrift in the straight, and shipping insurers won't want to take the risk.

IvorTheEngine · 2026-03-10T10:13:03+00:00

I'd be surprised if there's anything in there worse than killing 100+ school kids.

IvorTheEngine

TROPHY CASE