nicknorman

To some extent it depends on the nature of what is being supplied. If it is a resistive load eg a heater or kettle, then a phase jump is not an issue. But if it has a transformer or motor it’s another matter. People don’t understand how ac works, for example if you ask people how a Combi Inverter supplements incoming shore power in “power assist” mode, they will tell you that, well, I guess it supplies the ac at a slightly higher voltage than the shore power or something…. Which is of course total BS! The inverter will supplement the shore power by supplying at the same voltage but trying to advance the phase of its supply vs the shore supply’s phase. Phase is king when it comes to ac systems! Anyway, let us know the outcome of starting the genny with the ac selector switch already set to that way and inverter already off. It will prove or disprove the point. Not if it is a double pole break before make, which apparently it is. The Inverter neutral is not connected to anything when the switch is set to shore power. And assuming the NE bond is the inverter side of the switch, which it must be otherwise the RCD would be tripping all the time.

Switching near-instantly from an ac source at a certain phase, to a different ac source at a random and different phase, is quite a brutal thing to do. Although I can’t immediately see why it would trip the RCD, I would suggest the following test: switch off the inverter first, then changeover the switch, then start the generator. This eliminates the transient “shock” of a near instantaneous major phase change. If that trips the breaker then there is an earth leakage fault but if it doesn’t, then I think the issue is the inadvisability of nearly instantly changing to a supply of different phase. As background, a Combi inverter charger can instantly switch between say shore power and, when shore power is unplugged, inverter power. But the inverter circuitry has been “tracking” the phase and frequency of the shore power so that when it suddenly needs to supply power the phase and frequency are matched for a seamless transition. The same applies in reverse (shore power suddenly plugged in, inverter no longer needed) - there is a few seconds delay before the switchover happens whilst the inverter adjusts its frequency and phase to match the shore power, again resulting in a seamless transition.

I can't count both ways at the same time because the electrons aren't going both ways at the same time! Electrons coming from the solar will split, some will go into the battery and some will not go near the battery, instead being diverted to run the boat services (fridge etc). You can't expect the battery or the battery shunt to know about electrons that don't visit it! The MPPT gives the value because all the electrons generated by the MPPT leave the MPPT, and that is all it knows about. It doesn't care where they go. Similarly you could have a monitor to count all the electrons coming from the engine alternator, one for the electrons coming from the generator/battery charger etc etc. But as you say, it is probably not worth the hassle!

I disagree. If you select a 40C wash and fill with water at 45C, the heater will never kick in.

Unforunately I think the two compact makes Candy and Zanussi are no longer made, and like you I am struggling to find an alternative.

There is no such thing as a 1.5v rechargeable lithium cell, the chemistry can’t do it. The 1.5v AA batteries have 3.6v Li cells and boost/buck/bms circuit to convert between the cell voltage and the 1.5v output and give the usual protections. Probably the major manufacturers think this is too difficult and unreliable. As to whether safe, you are into the area of exploding lithium polymer cells. Probably ok if the electronics hold up and you use the purpose designed charger, but I would want to charge them outside the boat.

Can’t remember exactly, but it was something along the lines of this https://www.amazon.co.uk/heating-foil-130Watt-underfloor-laminate/dp/B07DL1Y79M

it would be easier and less Ah-consuming to place heating mats under the battery, like wot I did. Plus a bit of insulation so the heating doesn’t disappear downwards.

Yes it’s funny how seeing a windlass left on the spindle of a raised paddle makes one cringe! I did notice the volockie removed it when the presenter walked away to talk to the other person.

I think the heater is only enabled at 0C. In any case, it doesn’t use current from the battery, it only uses charging current coming eg from the solar. So you would for example see a few amps charge from the solar controller or shunt, but no charge current on the BMS. It diverts any available charge current to the heaters, until the battery is a few degrees above zero. The battery is warmer than outside due to the canal water. Even when the surface of the canal is zero, the steel hull which is fairly heat-conductive, can transfer some heat up from the water at the bottom of the hull which will be warmer, plus some heat transferred from the living quarters.

Well, there is the usual 14 days. But no short term restrictions.

Do you really need it on the roof, as opposed to a front or rear bulkhead? A vertical surface is going to be less prone to collecting water and leaking, and bear in mind the aerial needs to be easy to reach when you want to align it. Have you considered terrestrial tv vs satellite? The latter has the advantage of working anywhere in the country and with the signal always in the same direction, but the disadvantage that the signal is completely blocked by any sort of foliage or buildings in the line of sight to the satellite.

Yes. Cold water weeping out of the PRV at the cold water inlet. The pressure of course deriving from heating the water further up. But the pressure in a non-flowing liquid is the same throughout (discounting head). It doesn’t matter where the PRV is located, it can vent any excess pressure.

The OP stated no accumulator fitted. So the whole water system is one sealed thing (nrv in the water pump). Having the PRV in the cold side has the benefit of not wasting hot water out of the PRV.

Mr Catto? Baron Catto if you please!

It says they pulled the boat along the bottom to nearer the junction so they can build a dam behind it. “Once in location, the winch was able to haul the boat along the drained canal away from the breach hole," the authority said in a statement. "The boat is now safely located next to the lift bridge," the council said, adding that it would be refloated in the new year, when a dam would be constructed beyond the boat.”

I see the boat that was hanging precariously over the edge has now been pulled to safety and will be refloaded shortly. I am not sure how much donation is needed to compensate these poor people from the tragedy of being separated from their possessions for a couple of days. Probably £10,000 should do it.

It would help if you told us how you charged them. Obviously we can’t know from what you have posted so far, but it is a “theme” on here that the cause of problematic batteries is often simply not charging them fully, repeatedly. It can be a mistake to rely on a charger going to float, plenty of chargers are not good at knowing when to go to float and do so prematurely. Really you need to monitor the voltage and current towards the end of charging to be sure it is being charged fully. As you mention, it’s much easier to properly charge in summer when the solar is doing all the work and the consumption is much less. Im also a bit confused by your OP which says that the batteries were all disconnected from each other, but then only give one voltage reading per day. It seems unlikely (but not impossible) that the isolated batteries each had the identical voltage. Way forward is to make sure you properly and fully charge the batteries, then disconnect them all from each other. After a day or so I would expect to see around 12.7 or 12.8v and it should not change over the next 3 days. If there is a problem, it’s highly unlikely that the same problem affects all the batteries in the same way, so you might find one battery has a decreasing voltage due to a partially shorted cell etc, and when they are connected together in normal use this pulls the other batteries down

You poor thing, it’s SO UNFAIR!

Now now children!. Think of the poor mods who have to spend their Christmas time clearing up your playground mess.

There is definitely a recent trend for people to get terribly upset about something relatively trivial that happened to someone they have never met, whilst completely ignoring actually horrific things.i don’t think it has a name, but it probably will do eventually. As an aside a smallish WhatsApp group I’m a member of, returned a few condolences when I reported the death of my mother. But a few weeks later, the report of the death of someone’s ancient Labrador elicited far more, and far more heartfelt condolences. As a society we have completely lost the plot!

But I think the caution on here is valid. You are presuming that money donated to this cause will be distributed appropriately. In this particular case I’m inclined to agree but in general, unfortunately the internet enables horrible people to exploit tragedy and in fact anyone could have set up that GFM page to scam people out of money.

I disagree. The NHS is free at the point of delivery. Whereas every boatyard charges lots of money.

We would need to know the recent history in terms of charging and discharging. Bearing in mind the voltage started out at 12.56v this could have been following a short period of charging and the decrease to 12.36v is just the dissipation of surface charge. In order to be sure I think you should fully charge the batteries (14.4v until the current has fallen to 2% of capacity, which will take many hours) and then let them rest for a few days.