IanD
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Posts posted by IanD
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7 minutes ago, blackrose said:
Ok thanks, that gives me a better idea of how much data I might be using. Which is why I'll stick to 500GB/month when I get a new prepaid SIM card.
Our average daily use is considerably less than that, but I'm pretty sure 200GB/month wouldn't be enough if we were onboard for a month -- 500GB/month would be though.
I did also have a cheap 500GB/month Three SIM from Scancom, but every time I tried it out it was slower than EE, sometimes drastically so when out in the sticks. -
1 hour ago, nb Innisfree said:
Isolation transformer better than galvanic isolater
True (which is why I've got one!) -- but also bigger, heavier and a *lot* more expensive, which is why most canal boaters have much smaller cheaper GIs... 😉
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49 minutes ago, GUMPY said:
Even if you are not on full time Scancom is cheap.
We have an 80gb/month SIM bought a month ago on special offer. It runs out Jan 2027 cost me £44.99.
Being away once every month between March and October apart from August that's 14 months use at £3.21. try getting that much data for that price elsewhere.
Only downside for us with Scancom is that the SIM doesn't work outside the UK😟
However if you want "big data" on EE when you're on the boat but only spend a limited number of weeks a year on it, it's cheaper to use 1pmobile with a cheap (£3) 1GB/month package when you're away from the boat (assuming you use remote monitoring which I do, about 500MB/month) and top up with a 200GB/month (£18) or unlimited data boost (£25) when you're onboard. This also means you can switch network any time should you need to, if it turns out that EE aren't good where you happen to be.
Before anyone says "why do you need that much data?" the answer is TV streaming, usually HD and sometimes UHD which eats data -- looking back at logs, up to 25GB/day maximum...
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39 minutes ago, Russ T said:
Yeah, that is incredibly cheap.
Scancom are, so long as you're happy to pay in advance and be committed to that network -- by far the best deal if you're on the boat all the time.
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7 hours ago, Jen-in-Wellies said:
When I needed an extra two bus bars to connect my cells in parallel for top balancing, I made them by hammering some 15mm copper water pipe flat, drilling holes and polishing them. They were similar cross sectional area to the Fogstar ones, but without the flexible hump. Worked fine for doing the top balance, where the current.was under 10A. See below, connecting cell 2 to 3.
The reason the battery manufacturers use those multilayer humped busbars is to prevent stress on the terminals if the batteries move even slightly, for example when a boat hits something.
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1 hour ago, Alway Swilby said:
Talking of beer I was brought up on Fullers. Chiswick Bitter was my favourite at 32p a pint. Sometimes I had London Pride instead at 34p.
Chiswick is unfortunately impossible to find now, may have been dropped -- I always preferred it to Pride...
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2 minutes ago, blackrose said:
Thanks, are you streaming TV?
Everyone's on 3 around here but I'm not sure if that's because we're all misers.
According to Ofcom 3 is slightly better than EE in this area and I heard 3 have just merged with Vodafone so once they sort out the technical issues they've been having after the merger hopefully things will improve.
I'm sure the Ofcom website used to show coverage of mobile voice signal and data signal separately but they don't seem to do that anymore. Maybe it's all the same these days.
The problem with coverage checkers like that is that they're looking at signal strength, not network congestion which is often a bigger problem -- especially on 3 because lots of people use this as it's the cheapest network for big/unlimited data, result is it slows to a crawl at busy times.
EE has better overall coverage for signal but also suffers less from congestion than 3, because it's more expensive and has fewer data gobblers using it...
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2 minutes ago, DHutch said:
Fair enough.
I guess maybe one last consideration is the boat itself, displacement, lines, prop. But I presume the above graph is based on a reasonable quality prop.
Tixall is a fairly standard narrowboat with a 23" X 24" prop. so probably not far off comparable. And better than some of the awful props some new boats have, and or bent up mess some boats have! Emilyanne is a touch heavier than most, drawing around 2ft9 under way to swing a 26x32" prop.
Most (all?) steamers end up with big props because torque is high and engine rpm is low -- not in any way a bad thing in itself (quiet, good stopping power), except that it also means a deeper draft than normal is needed, so the boat displaces and draws more, and this increases the power required for propulsion (and fuel consumption) especially if the canal is shallow (badly dredged) and/or narrow... 😞
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5 minutes ago, MtB said:
I'd say if you have all of that lot in your boat you are quite exceptional. Especially the dishwasher and the "washing mashing"!
And who in their right mind runs an immersion heater off their batteries!!
Anyone who's got enough solar power that there's some going spare even after charging the batteries... 😉
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51 minutes ago, DHutch said:
I bet its less than that, given how relatively oversize they are for the task, like 50hp when you typically only need more like 4hp.
However I do am somewhat surprised its 'only ten time more fuel' (or 15x if you take 12mph vs 0.8mpg) for the steam boat.
As suggested, a very large amount of heat goes up the funnel, and a significant amount out of the condenser which is raw water cooled.
No superheat, and no feed water heater, although the condensate from the hot well is good and and warm.
Working pressure for EmilyAnne is 200psi, and we aim to keep it at around 150-180 cruising.
Tixall is 150psi working and especially now she is oil fired I presume Matt runs her pretty close to that.
EmilyAnne and Tixall actually have near identical engines, the only two from the specific builder, and both have vertical fire tube boilers, all be in difference shapes.
Cut off is very good for steam locos, when you are running at high speed and low loads. But on a boat you obviously have a huge great torque converter on the end of the shaft. So you dont really get the same effect, so running in full gear is much more common in a marine environment.
That figure was taken from actual efficiency curves for a Beta 43 with standard prop, about 19% efficient at 3kW/4hp output at 1300rpm -- see attached plot. Peak efficiency is 32% around 2000rpm, but this will never be reached when driving a prop (blue line).
A condenser should mean higher efficiency than a direct exhaust like a railway loco, that's the whole point -- yes heat goes out of the condenser into the cooling water, but less energy is lost overall than by just throwing the steam away, especially since the expansion ratio can be bigger. But maybe with only double compounding this isn't that big an advantage...
As you say compounds are less sensitive to cutoff than simple expansion engines (and use longer cutoffs anyway), and also more efficient -- even non-condensing ones.
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16 hours ago, MtB said:
Cue nine pages of whining about how unfair this is!
Just imagine the number of pages of whining on CWDF if CART went to (logical!) area-based pricing... 😉
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6 minutes ago, NB Saturn said:
They do have an advantage in being a lot easier to recycle at then end of their lifetime, if that is a concern.
Given that their lifetime is so much shorter, that's kind of necessary... 😉
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1 hour ago, GUMPY said:
When I was younger the local drink of choice was Light and Bitter. Me I was different I drank Broadside and Bitter. That was in the days when bottled Broadside was way stronger than it is today.
Mixed Young's Ram (bottled) and Special (draught) used to be popular in London... 😉
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Just now, magnetman said:
LTO is good.
Cuts out all of the problems.
Including costing 4x as much?
I'm sure that'll go down well with those doing possibly-problematic LFP installs "on the cheap" as noted above... 😉
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13 minutes ago, NB Saturn said:
Surely the easiest answer to cover this usage case (and target market) is to use LFPs with built in heater - even Sterling do them.
As do Fogstar and various other suppliers. But if you're looking to rabbit on endlessly about LFP problems -- real or imagined -- this doesn't matter... 😉
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9 minutes ago, Gybe Ho said:
Yours is not the only proper boat on the canal network. I have the rare capability for CWDF, to consider the world from the perspective of others.
There are 7000 continuous cruisers on the network who will form the bulk of the offgrid x 365 community. This is where the bulk of the LA to lithium upgrades will be happening with many on cruiser stern boats. On such boats the batteries live on the swim plate with little thermal protection. Drop in lithiums are going to get routinely chilly in winter.
The reality is that 99% of narrowboat lithium batteries will have "cheap nasty" chinese made lithium cells protected by "cheap nasty" Chinese made BMS boards.
And in that case if the batteries get cold and there are no heaters, they won't be able to charge them.
That's not the fault of LFP batteries, that's the fault of whoever designed/bought/installed a crappy LFP system on the cheap and without thinking -- probably also with parallel LA and long wires, and a BMS that gets hot at high currents and dies after a few years. Nobody made them do it... 😉
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4 minutes ago, junior said:
My point about not having hot water in the morning was probably now worded the best, but what I really meant is that at the time we all like to have a bit of hot water such as in the morning when woken up, unless you've cruised the afternoon before, you're unlikely to have any. There is a finite length of time your water will stay hot in the calorifier, and if that's your only means of generating hot water, I can imagine it soon become frustrating and costly to install another means of heating your water.
If you're going to be living in a marina on hook up all the time, it probably wouldn't cost too much to get an immersion element put in the calorifier, but if you're out cruising or living on the towpath and only cruising now and again, you'll need an instantaneous water heater, which I understand are not easy to retrofit these days due to regs, or a back boiler and pipework adding to your solid fuel stove, and this would be costly if at all possible. Webasto type devices are also an option, but I fitted something like this on the cheap recently and it still cost me over a grand.
When we're out cruising (series hybrid boat) I normally start the (very quiet, cocooned diesel) genny up at 8am while we have tea in bed, which heats the water up and charges the batteries -- or if we're not going anywhere and don't need the power, I do the same with the diesel boiler. Either way, there's plenty of hot water when we get up and shower. Same thing before we stop in the afternoon/evening if we want showers then. In between the hot water cools down, but it's still warm and there's usually enough for at least one shower at any time.
I guess that's the disadvantage of not running a diesel engine all day, you need to think a bit more... 😉
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6 minutes ago, Gybe Ho said:
Victrons curtail charge rate at 5 degrees C, are they not proper enough for you?
BYD -- who are the world's biggest LFP manufacturer, *hundreds* of times bigger than Victron, and make their own cells and BMS from scratch -- start to reduce charge rate below +12C but allow charging at reduced rates all the way down to -10C, see numbers I gave above.
The low-temperature requirement is driven by off-grid domestic installs in cold countries which is a *huge* market, far bigger than boats, and that's what pushed BYD allow lower-temperature charging -- they updated their software about 3 years ago to do this.
I'm sure Victron -- who are much smaller and relatively new to the LFP game, but still far bigger and better-resourced than the small cheap BMS manufacturers -- will catch up eventually, because that's what their markets will demand... 😉
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5 minutes ago, Gybe Ho said:
No. After reading multiple alarmist posts about accelerated battery decline when the operating temp rises from 20 to 30 degrees Celsius I thought someone should highlight that low temperature is the more prevalent concern with lithiums on a narrowboat. You mocked my post so I pointed out that BMS's by design curtail charge rate below 5 degrees Celsius. You might think charging lithiums at a low temp is a laughing matter but those who design BMS circuits think otherwise.
In the case of an offgrid x 365 narrowboat it is more likely a BMS will step in to protect a battery due to low temp than high temp. You should know this because you have previously claimed your lithiums we mounted well below the waterline where the canal water temp will be warmer than a thick layer of ice at the surface.
Which is why I'm not worried about it... 🙂
See post above about what a properly designed/integrated BMS/LFP system should do, as opposed to cheap nasty off-the-shelf BMS from China... 😉
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16 minutes ago, alias said:
Probably, it would have been less ambiguous to type 5°C if that's what he meant.
Even so, he's still wrong for properly managed LFP/BMS systems, see the numbers I quoted.
The fact that a lot -- especially cheap ones -- just go from full rate above 0C to zero below just shows how little their designers understand LFP batteries... 😉
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9 minutes ago, Francis Herne said:
It's a condensing double-expansion compound.
The new oil burner setup could use some adjustment - the exhaust temperature is very high so not making the best use of heat, some ideas to put coils or chains down the tubes to slow gas flow and get better heat transfer. The burner is only on about a 30-50% duty cycle at cruising speed so adjusting it for lower output over a longer time would help.
Cutoff is controllable but not often used - on a compound it makes less difference but I'd be interested to experiment with it.
That's pretty poor then. A narrowboat diesel engine at cruising power is about 20% efficient, a big single-expansion superheated high-pressure non-condensing steam engine (railway engine) might manage 8% at peak efficiency but rather less at low power levels. Compounding and condensing both push efficiency up, but having a small low-power engine pushes it down again (more surface area and frictional losses). Even so 10x the consumption implies about 2% thermal efficiency which is pretty appalling... 😞
Out of curiosity, what boiler pressure do you run at? (I assume the engine is not superheated)
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2 hours ago, DHutch said:
Apologies, I did miss that!
I actually intentional excluded it from my list, in order to focus on narrowboats. But you are very much correct, and it was interesting information.
While we are on the topic of 'not narrowboats' when I was on Steam Tug Challenge on her way back from Pegasus Bridge in Normandy it was suggested that the oil consumption was around 10litres per minute, which is 600l/hr. And if you assume to a trip length 300miles, over 26 hours. 11 gallons per mile, or 0.087mpg!
So very broadly, a steam narrowboat does ten times less miles to the gallon than a diesel narrowboat, and a 240ton ocean going steam tug does ten time less miles to the gallon than that.
Maybe.
The last one isn't surprising, about 10x the fuel consumption for 10x the displacement... 🙂
The first one is pretty surprising though, given sensible guesses for the thermal efficiencies of a non-condensing single-expansion steam engine (is that what you have?) and a diesel engine I'd have expected a difference of a few times (3x-5x?) but not 10x. But then so much depends on the details, if you don't have variable cutoff valve gear and reply entirely on throttling to vary power (do you?) then 10x is perfectly reasonable... 😞
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4 minutes ago, Gybe Ho said:
And treating them properly requires not charging them at a normal rate below 5(c). This protection is baked into BMS design.
With people now buying lithium drop-ins to replace LA batteries mounted on a swim, I suspect a low temperature operational hiccup is more significant than the chemical wear & tear high-temp concern.
I assume you mean 0.5C? 5C is quite large, 500A for a 100Ah battery (which probably has a 100A BMS)...
Low temperature charging is another area where the integrated battery/BMS suppliers can do much better, rather than just stopping charging completely at 0C as many do. For example, the BYD 14kWh 48V pack (280Ah) has maximum charging current of 160A (0.6C) from +12C to +50C, 80A (0.3C) from +2C to +12C, 60A (0.2C) from -10C to +2C.
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15 minutes ago, Gybe Ho said:
The temperature issue for lithium batteries on a narrowboat is the amount of cycling they experience well below the ideal operating temperature when located outside the main cabin and above the waterline.
This is like two bald men arguing over a comb -- lithium batteries on canal boats are likely to outlast the owner and maybe even the boat, so long as they're treated properly for charge and discharge -- the ambient temperatures are generally suitable for them, and several thousand cycles at 100% DoD (or 2x-3x that at more usual DoD) means lifetime will be so long as to be not worth worrying about.
Here's an example of 15 years of heavy use -- much heavier than most boats! -- with close to zero capacity loss... 😉 (but with a properly designed BMS...)
https://marinehowto.com/happy-15th-birthday-to-my-lifepo4-battery/
Improving onboard Mobile communications
in Boat Equipment
Posted
I suspect the clue is "Everyone's on 3 around here but I'm not sure if that's because we're all misers." -- network congestion due to too many users all trying to do things like streaming TV at the same time, which is unlikely to get better... 😉