Detling

Granary wharf is on the canal but being a short/small pound goes up and down a bit about a foot. The pontoons are 48 hr but not sure if all year or not. The walls are 14 day, the dock bit by the lock is a flooded dry dock and has stepped sides so fine if the water goes up not so clever if the water drops. The holiday inn and Hilton are the same place (hhilton) Wi-Fi is free and fast.

Canal boats on still/slow water represent a small subset of boats, and with recharging points available can successfully be electric. A tidal waters boat often needs to be able to-do 10 knots into waves to be safe, not so easy with electric, and a RNLI. Lifeboats frequently do 25 knots into big waves and can be at sea for 24 hours, there is not room for the required batteries for such performance. As Greta said it is politicians blah blah a lot of hot air. But where we go to in the next decade should be interesting, but just not where they say today.

So how about 4 of these ? https://www.lifebatteries.co.uk/product-page/150ah-lifepo4 £635.00 x 4 = £2540 for which you have 600 Ah capable of 400amps plus discharge charge ridiculously fast so some alternator protection system to control the alternator add 4 or 500 quid and as they say jobs a good un. Lithium prices have come down and will probably go down more yet. It is getting close to a no brainer on a new build as you are likely to have to replace at least once if not more with any form of lead for the same lifespan. Retrofitting lithium is more expensive as so much needs changing but when buying new you haven't got those bits to throw away. Another 'essential' is solar even if only a few hundred watts, it will save CO2 production somewhere either your engine, or the power station, and even on shorepower will pay for itself in a few years, offgrid probably in the first year or so. https://www.bimblesolar.com/offgrid/complete-packages/295W-victron-kit-mppt-mounting £450 just needs fitting.

Early 2023 will be a lot easier, I had to book 11 months in advance for mine. Narrowboat so not same tunnel/dock.

Your panels will take 55 feet so totally fill the useable roof of a 70 foot boat, you lose about 6 to 7 feet at the front due to the pointy bow,and about the same at the stern due to having to have a hatch and a means of steering so a 70 foot boat only has about 55 feet of roof space. The tilting will help in winter (probably double your harvest) but even so you will be lucky to get 20% of rated power for about 4 hours in winter on a dull wet day you will get much less than that. You may also find it difficult to ensure that no part of that solar array is shaded, even by a rope. I wish you well but the laws of physics are not to be ignored.

Blame the VAT rules for these monsters. If they were a few cm narrower then they wouldn't qualify for VAT free (if they really do?) and as a buyer I probably wouldn't notice the 2cm narrower inside, but would notice the 20% VAT on the bill.

They need the 12volt power to them usually 24x 7 certainly for the 15 minutes after you turn the device off using the control wire. Most controllers just switch 12 volts onto the control wire to initiate the start up sequence and then open the control wire circuit to initiate the shut down sequence this shuts the fuel off and continues to run the air fan and water pump until the burner unit, and heat exchanger have cooled to a safe level. Just cutting the power risks the unit sitting there with a glowing red hot centre, probable causing the water to boil sending steam down the pipes and possibly splitting them.

Shroppie locks are nicer than the T&M IMHO.

It won't be moved much I suspect and will become a permanent fixture in some marina

Cos they are cheap, but look good and work for at least the 12 month warrant period.

Do check that the plastic filter is bss compliant, usually plastic is a no no.

I have had good results go with a tree pruning saw, it copes with most things but doubt it would win with a chair frame. It was great for a big builder tonne bag which are virtually indestructible.

It seems most battery failures these days are from positive grid corrosion and not sulphation, possible causes are long solar charging when batteries are full and/or float charge voltages to high.

If my understanding is correct the OP has a 24V bow thruster and a 12 volt starter battery. This makes the common charging starter/bow thruster combination, like mine both 12 volt so easy and fitting a small solar panel keeps both charged. 24V makes it easier to combine domestic and bow thruster, but I don't know of any dual output 24V solar controllers. So maybe the 240 charger is a good solution if worried about cooking the batteries over a long period on charge just got a 7 day time switch and charge for a few hours once a week.

The reason there have been more short stoppages I think is due to the number of locks without all paddles working and yellow tape over a broken one, they have been using yellow bags for a while now so the ones with tape failed several years ago and now when its mate fails the lock is not useable so becomes a stoppage. If they had bothered to fix the old broken paddle they would be able to put a nice yellow bag on the newly broken one and fix when convenient in the next few weeks.

I have had some flicker because they are too hot so the internal regulator shuts off bulb cools comes on again they were 5 watt LED changed to 4 watt everything fine.

Could you not use a small relay controlled by the bmv, then the relay contacts get burned not the bmv relay.

Maybe a restrictor valve to the boat bit when the engine is running, I have a heat exchanger from my modern engine to the boats radiators and whilst fine when running at cruising speed, at Tick over as well as in a flight of locks I need to reduce the heat transfer to keep the engine temperature high enough.

Boat calorifiers are built to withstand high pressures and most have two or more heating coils, one for the engine coolant to heat the water when the engine is running, and the other, for in your case the webasto to heat the water. They usually run at 3 bar most domestic tanks are designed for about 0.5 bar.

Make sure the cables between the charger and batteries are thick enough to only have a very small volt drop. Just because a cable is rated to carry over 30 amps is not enough, you need to use a volt drop app/calculation. The required size may be a lot thicker than you think. If the wires are to thin the charger will think the batteries are fuller than they actually are. As the charger measures the voltage at its terminals so is measuring battery voltage plus cable volt drop.

The existing paint will have faded on the boat in the sun. I took my gas locker lid (easily detached) to a paint factors who did their magic scan and gave me tin of perfect colour.

Thanks for that looks like what I hoped. Need to play a bit and probably get a few.. Re BSS I do intend to have a mechanical isolator as well just want a switch to save grovelling under the deck boards (cruiser stern) to operate the isolator, near the battery but not that convenient for frequent use.

Yes there are new ealth and safety rules around but I guess a bit like declaration of propulsion for red there will be some who strictly follow and some with a dodgy eye who want a sale.

So if I understand correctly, one solid state relay in the line between an inverter charger and a battery in the off state would stop current flow one way and allow current flow the other way but with a diode volt drop. In the on state current could flow either way with only the IR volt drop.? That perfect switch looks good but I can't find prices and with shipping and duty probably prohibitive.

Is it possible to use DC Solid State Relays as a battery switch (in addition to a mechanical isolator). The SSRs I can find have + and -ve terminals on the output. I know you can use two Mosfet's in series, one one way round and the other reversed, to switch DC bidirectional current flows, but can't find any SSR's so configured, and I don't know what the volt drop of a series pair would be. My electronics knowledge is mainly from before 1980 so before these devices, I diverted into computer systems so not needing power switching.(Triacs I understand but that is AC)