IanD

I got one but it took some time to arrive...

Normally around 3kW/4bhp at the prop is needed for canal cruising as a rule of thumb. If 6kW turns the prop at 1650rpm, 3kW will turn it at about 1200rpm. 700rpm, no way...

Unfortunately your statement is blown out of the water when you look at which countries have the happiest population, because the high-tax "socialist" countries like Sweden and Finland and Norway -- who use the taxes to pay for things that people find useful like hospitals and nurseries and homes for old people, not things like HS2 and aircraft carriers with no (or a few very expensive) planes and ballistic missile submarines -- always come out at the top of the list. Of course this is personal taxation not business, and it is difficult to compete in an open global market if your industries are heavily taxed, However since we've hardly got any manufacturing industry left, this isn't such a big problem for the UK... 😞

Yes 🙂

If it's the Sunshine one the data sheet says it has internal fuses, which should protect it (and cables/batteries) if things go horribly wrong -- but it doesn't say whether they're user replaceable or not if this happens. I'd say the risk is low in the short term for trying it out, but add a megafuse when you can get one. If it's a different inverter and the data sheet doesn't say it has internal fuses, I wouldn't risk it.

Wrong numbers -- 1500W out of inverter means 1650W in (using Sunshine efficiency numbers) which is about 150A assuming battery drops to 11V under load. Fuse rating is a matter for debate... 😉

Same approach as Brexit -- apply insults instead of having a meaningful discussion which might help the OP. So I won't bother rising to your bait again -- go and engage in online keyboard-to-keyboard combat with somebody else.

These were the kind of >1kV traction thyristors where one of them is a whole silicon wafer in a circular can, being tested in the lab at several thousand amps... I agree, I've seen a 100,000uF electrolytic go bang and spew its guts all over the room 😉

No. But I've seen what happens when a puck thyristor carrying kiloamps and kilovolts fails, which is *much* more spectacular (and noisy)...

No (good quality) fuse with a given rating should blow due to aging effects; the whole point of the rating is that the fuse should be able carry it for the lifetime of the device, even at the maximum rated ambient temperature -- this is what the fuse rating means. What it's intended to protect (battery, cable, switch, device, ar*e on fire) doesn't matter, because not all failures are dead shorts. The general principle is that a fuse should be correctly sized to carry the maximum intended current, then it will do the best job of protecting the circuit and what connects to it no matter what goes wrong. It's why 13A plugs (for 3kW 230V loads) have 13A fuses in them, not 26 A ones. If the fuse is *only* supplying the inverter -- which is what the OP seemed to be suggesting -- then it should be sized to suit this load, which means 150A for a 1.5kW inverter. If it's also supplying other high-current loads then it should be bigger. Plenty of equipment -- especially low-cost stuff from China -- which should have internal fusing doesn't, because this saves money. And it's not much consolation for them telling somebody they shouldn't have bought that cheap Chinese inverter as they watch the fire brigade putting out the last dying embers of their boat, even if it makes you feel superior...

Nothing, it all stays contained inside the fuse body...

Let's wait and see what the EU response is to the UK request to delay Article 50. My guess is they'll stick to their guns and say that without a significant change in the UK status (moving "red lines", second referendum, general election) which could lead to a deal acceptable to both sides, a delay is pointless since it will just lead to more squabbling with no resolution in sight. Then the ball's back on the UK side, the government has to decide whether to do something *very* quickly to persuade the EU to allow a delay (red lines, referendum, election) or face the "no-deal" or "no-Brexit" crunch referred to earlier. In other words they've got five options, all of them seen as bad by large numbers of people/MPs, and they have to figure out which the least terrible choice is and then how to get it through Parliament. I wouldn't bet on what's going to happen given the surprises we've had in the last week or so...

The problem for the government/Parliament would be which of the two to choose, since each one will cause uproar in one half of the population or the other. If they allow a "no-deal" Brexit they'll be crucified by business, finance, MPs, ministers, economists, and the roughly half of the population who want Remain. If they unilaterally cancel Article 50 they'll be crucified by large parts of the press (Mail, Express, Telegraph, Sun...) and the roughly half of the population who still want Brexit. Either way they're deep in the sh*t... [Q. What have you got if you have a lawyer and a politician up to their necks in sh*t? A: Not enough sh*t...]

The EU can't insist that we leave on March 29th with "no deal", but they can refuse to allow a delay which puts the ball back in the UK's court. Then it's up to the UK to decide on "no deal" (hard Brexit) or "no Brexit" (unilaterally withdraw Article 50), there are no other options left at this point. It's like two jugglers with a live grenade, nobody wants to be the one holding it when it goes off...

You're assuming that a cheap possibly shoddily-built inverter has an internal fuse... Yes a "zero-ohm" dead short will blow a 400A fuse pretty quickly (or a 150A one), but not all faults are dead shorts, especially if the return current path for the short isn't through the heavy-current cable. Drawing 1000A or so for tens of seconds through a 400A fuse isn't going to do the cables or the batteries any good. There's still no good reason to put a 2x rated fuse in -- no advantages, only disadvantages. Why do you think it's a good idea?