smileypete

There's cheaper pure sine inverters too: https://www.amazon.co.uk/1000W-power-inverter-battery-electricity/dp/B00AEVHTNG Also there's some really cheapo ones out there but most (all?) of these are best avoided. For a ballpark estimate, a typical inverter should have a continuous rating which is 10x the wattage of the fridge. Mastervolt and victron etc are good but somewhat over rated as they're not 100% reliable for everybody.

For big installs there's double pole solar DC isolators available: https://www.electricalguys.co.uk/salzer-dc-isolator-for-solar-installs-h226-81400-710n1.html If you squint at the pic you can just make out that each pole uses 2 contacts in series, I guess it's just a 4 pole switch rewired appropriately. For a modest 36V or 72V install a standard 2 pole MCB might work just fine. More info: http://www.plctalk.net/qanda/showthread.php?t=95968 Edit: Squinting at the above pic in this topic it looks like the breakers are rated 125V DC so that should be fine for the solar side.

£70 sounds a bit too pricy, they usually go for around £30-40. A much better option could well be the tried and tested Electoquest twin output 30A charger for £125: https://www.ebay.co.uk/itm/FULLY-AUTOMATIC-5-STAGE-MARINE-BATTERY-CHARGER-12V-30A-TWIN-OUTPUT-/132377426875 Pretty much plug and play, but has a gajillion options if you really want to play with them.

Batt SoC shouldn't be an issue with plentiful solar this time of year. This of course assumes that a proper power audit has been done (a common omission!) (Surely three smartguages buys rather a lot of solar...)

Glad it seems to be sorted, could also be worth finding out the idle current of the inverter at some point, they're usually pretty good these days.

So from subsequent info the OP is running a mains fridge plus inverter losses plus laptop from 300W of solar, via knackered batts. Reading between the lines it sounds like demand from the nackerd batts was precariously close to supply from solar and engine running, and is now out of whack due to lower solar output, plus longer fridge running, all due to high summer temps. Probably the controller is not to blame here. New batts would likely help the most, and possibly a bigger solar setup would help during summer at least, if a power audit and monitoring indicates so. Nope but there are liveaboards who seem to get by OK doing just that. It can't easily be done on a shoestring outlay along with a shoestring of knowledge unfortunately, that I can predict...

For a healthy lead acid batt, full charge is indicated by sufficiently low tail current at the correct charge voltage. Unfortunately, for most boaters, the above is cryptic enough to lead to the destruction of £?00s worth of batts. (ETA: It doesn't help that some of 'the experts' try and make it seem more complicated than it really is - why?)

If the wheel is functional, leave as is, it's 'character' ?

Doesn't mean he's not highly opinionated, or possibly downright wrong, or that the sterling charger manuals may not contain misleading twaddle... 240V fridge makes sense in some cases but not always.

It'll run quieter if the supply voltage is reduced a little. One way is to repurpose a FULL BRIDGE RECTIFIER*, you'd need to connect the '+' terminal to the red wire of the pump and the '-' terminal to the red wire of the supply (doesn't make much sense at first glance I know...) and leave the AC terminals '~' unconnected. Here's a typical one with handy blade terminals. https://www.ebay.co.uk/itm/KBPC2506-Bridge-Rectifier-Diode-25A-600V/282555840569 Each one in the supply would reduce the supply by 1.2V, or around 10% of a 12V supply voltage... . * A FULL BRIDGE RECTIFIER is usually used as part of a circuit to convert AC voltage to DC voltage.

There's some DC immersions around, if chosen carefully they could be run directly from the solar panels themselves. For instance a 48V 1000W immersion would draw about 400W if connected to some domestic panels wired in parallel to give about a 30V output. OK not as efficient as MPPT but fairly simple... ETA: Fairly cheap one here: https://www.aliexpress.com/item/DC-48V-900W-Low-Voltage-Solar-Water-Heater-Element-Immersion-Water-Heater-with-1-1-4/32529976515.html https://www.ebay.co.uk/itm/Heating-Element-Water-Heater-Immersion-Screw-Plug-48V-900W-With-BSP/323186206383 Would probably want it about halfway up a 50L calorifier to get a meaningful amount of hot water with 4 hrs of full sun, I'd guess you'd want about 500w of panels at a less-than-perfect but reasonably good angle to the sun, wired in parallel to give about 30V.

Where the ribs are the order would be: cabin roof/sides -> ribs -> batten -> vapour barrier -> lining plywood In the span between parallel ribs the order would be: cabin/roof -> thick insulation -> vapour barrier -> lining plywood Thick insulation can be up to the combined depth of the ribs and batten. Sometimes the vapour barrier incorporates a layer of thinner insulation, in the case of the foil bubblewap. This will end up getting sandwiched between batten and lining ply, but that's OK. Clear as mud?

I'd not have interior ply or a vapour barrier up against bare steel ribs, best to have batten in between, as Tony describes. The vapour barrier should go on the warmer side. Also the foil stuff works somewhat well enough as insulation if there's a decent air gap on at least one side, even 1" will do OK, though don't worry if the other insulation is too thick to allow this. Maybe worth a look at graded roofing batten and self drilling countersunk head 'tek' screws.

You have a 'breather' pipe of sufficient height, and the wires to any submersible pump or float switch can run down the breather. Sounds to me that 90% of sump boxes on boats are badly designed or installed, thus all the negative comments. ? PS what happened to the usual smileys, all I can see now are loads of 'emojis'?

(For a typical steel narrowboat...) I'd prefer engine block to hull, ideally near the prop if poss, then battery negative to engine block. Taking battery negative directly to hull may lead to some unexpected consequences to poor connections.

On a typical steel narrowboat I'd just bond the mains earth to the hull or steel bulkhead adjacent to the consumer unit, less likely for the earth wire to get bashed about than if it's running a few metres somewhere.

If all else fails, worth testing the pump on a bench? Or there's plenty of pressure gauges on Ebay for <£10 which will help tell what's going on. Could even be something like air in a horizontal calorifier after the tank has run dry.

Just noticed that's the MSW version, the PSW is about the same price after the easter discount.

For high startup surge loads, a decent low frequecy inverter should be more reliable, but the standby current is usually hideously high. (No easy answer I'm afraid...) https://www.ebay.co.uk/itm/2000W-24V-low-frequency-power-inverter-charger-UPS-LCD-2kW-24-volt-peak-6kW/112903324597

If it's just for keeping batteries topped up, maybe just fit a smaller plastic cased charger that doesn't use an earth. A modest solar setup won't produce anything really worthwhile in winter, but should still be enough. If the problem is purely down to inrush and not loose connnections, iffy filter caps, then an inrush limiter might work, eg: https://www.ebay.co.uk/itm/Inrush-current-limiter-230V-16A-for-transformers-power-supplies-LED/231650038237 https://www.amazon.co.uk/Inrush-current-limiter-transformers-supplies/dp/B00OZLSVB0 I've seen much cheaper chinese sourced ones but they're just a bare board, no nice case etc.

Can get 700x700 quadrant trays: https://www.victorianplumbing.co.uk/ventura-quadrant-shower-enclosure-various-sizes Wonder if a corner basin would free up a few inches?

Main thing is not to under charge too much, otherwise significant 'sulphation' will reduce capacity but also increase charge time as the charge current will go in more slowly. Proper fully charging a batt needs correct charge voltage - as stated by the batt mfr - and enough time for the charge current to 'tail off' and stabilise enough at a reasonably low level. Doing this every day of the year is impractical, so a full charge every few days seems OK for most people, with a lesser daily charge in between if needed. When new lithiums get cheaper they'll avoid the need for this madness, there's some good second hand bargains around by the looks of things, but they're not usually 'plug and play'...