nicknorman

Are the bridge keepers on the G&S employees or volunteers? Folk may remember that I was assaulted by a volunteer lock keeper - he hit me with his windlass - so I don’t have a lot of faith in CRT pitting officious poorly trained volunteers against boaters. It is a recipe for confrontation.

The CRT Ts and Cs have no legal standing.

The OP came on here asking for advice about his current situation. I doubt he came on here so a bunch of sad old people could have an opportunity to say “Oooh, you shouldn’t have done that” to make themselves feel briefly superior.

He does say that he was assaulted first. Yes it would have been better not to be goaded into an argument, but we are not all perfect!

Yes this is a concern! If it were summer, you could just tag along behind another boat going through the bridges. The thing is that if the OP has done something such as assaulted a bridge keeper (even if only in retaliation) then that is a matter for the police, not for CRT to apportion blame. Maybe there is history that we don’t know about? And in fact if the OP was the one assaulted first, maybe he should report it to the police, although of course a couple of weeks has now passed.

Obviously we are only getting one side of the story, but as you describe it there are a few issues - one needs a licence to have a boat on the canals, not to move it. So if the boat is still on the canals, whether or not you move it is not relevant to the licence. CRT are not empowered to tell you you can keep your boat on the canals but you can’t move it, other than when there is a general stoppage affecting everyone. I am pretty sure there is no legal mechanism to suspend your licence, you either have a licence or you don’t. If it were me I would continue to move my boat as I needed to (without telling them about it). What are they going to do, come and shoot you? However I suggest it would be advisable to keep a low profile and try not to get into any more arguments! I suppose you are on the part of the system that requires co-operation with land based people (bridge and lock operators) but whether or no CRT are efficient enough to send out an “arrest warrant” to their bridge and lock keepers to deny you passage, I somewhat doubt. I would aim to get off that part of the system and onto a part of the system where everything is self service (Worcs and Birmingham, etc) I would also make a formal complaint to CRT that CRT are acting outside their powers and being unfair, vindictive and unreasonable. And as soon as possible, take the issue to the waterways ombudsman so that at least there is a public record of events.

This seems to be something that has arisen in the last couple of years. However it could just relate to sole owners, not sure.

I’ll just mention one stupid issue which seems to be becoming problematic. Several people have reported that many insurance companies decline cover if any of the co-owners are not resident in the UK. Not quite sure why. Just something to check on before getting too deep into the purchase of a share.

Like anything else, a 3D printer is only useful if you have a use for it. I've been doing a lot of hobby electronics recently (started during lockdown) as it is something to keep my 67 year old brain from freezing up. Used (free) RS DesignSpark PCB for the schematic and pcb layout. Learnt to programme in C using Microchip's (free) MPLAB X IDE (my projects tend to use PIC microcontrollers). And the most astonishing thing is that a double sided pcb up to 100mm x 100mm with as many plated through holes as you like, silkscreen and solder mask on both sides, board outline whatever you like, really top quality with minimum track width and minimum track spacing of 0.005" can be obtained from China for ... ... £3.47 for 5 boards including shipping. Yes that is not a misprint, three pounds and fourty seven pence for five boards including shipping to UK. Less than the price of a pint these days. Or if you want 4 layer boards it is a hefty £11.30. I have never had a duff board. One of my recent projects involved a 3D accelerometer chip that I browsed from the RS website, quite cheap at a couple of quid. But I hadn't quite noticed on the spec that the 10 pad device was 2mm x 2mm with pad width 0.2mm and pad spacing 0.2mm. That is never going to work!!! But it did, at first attempt to solder it on. So having populated the board with mostly SM devices using solder paste and a hot air rework gun - £35 from ebay - I now need something to house it in. Bring out the 3D printer. But first, design it with (free) Fusion 360 cad programme. That in itself takes a month to work out how to use even vaguely! Then slice with (free) Cura and then pop sd card into 3D printer Ender 3 (£200) and wait for it to print. Here's one I prepared earlier, the angular position sensor using 2D magnetic flux sensor and diametrically magnetised spindle. Still awaiting the pcb to come back from china but it is 25mm diamter and pops in between the two halves of the casing . The actual chip is shown there in its packaging awaiting soldering onto the pcb. So is it useful? For me, yes.

On the other hand, fascinating that a multitude of fossilised lurkers have suddenly sprung to life! Must be something in the water at this time of year.

Anyway, I think I may have killed Gibbo, which is a shame.

I am in a similar situation, all Li domestic bank and the boat is plugged into shore power when we are in the marina, via Mastervolt Combi. Trying to regulate all this by limiting shore or charging current is never going to work, the only way is by adjusting the charge voltage. First of all, the Mastervolt has a "Fixed Float" setting. That means the voltage is fixed at the fixed float voltage setting. Then next step is to set this fixed float voltage to one that keeps the Li at around 50% SoC whilst providing any necessary current to run the boat's systems. This is around 13.2v This means adjusting settings on the Combi, in my case this is done via my custom BMS but it can reasonably easily be done via a PC especially if you are not frequently leaving the marina and wanting to fully charge you batteries beforehand. Victron offer a number of gadgets to assist, such as the Venus OS gadgets that communicate with these sorts of devices (I think, no direct experience). But the bottom line is that to achieve what you want to achieve, you need to precisely adjust the set charge voltage of the Combi. Works well for me.

I am not seeing anything to disagree with. Which rather defeats the object!

Certainly the videos are a little patronising but then it is hard to aim at just the right level for every audience. I took the bit about "High School chemistry" as a joke. Yes I would agree that Peukert gives a good idea about the amount of capacity an inverter delivering a fairly high load can draw from the battery before it cuts off. As I said, Peukert definitely has a place in "time to run to flat" display. But is that really a scenario that most boaters want to be a part of? Most boaters don't turn on a high inverter load and want to run that until the inverter trips off due to under-voltage. What is a more realistic scenario IMO, is short bursts of high inverter demand, followed by long periods of low demand. For example we normally use an electric kettle, so that is 200A from the battery for 4 minutes. That will knock off about 14 Ah. Then we will revert to a modest 5 -10 amp load to run the TV or a phone charger for the next several hours. So the question is, should those 14Ah have Peukert applied, thus knocking say 20Ah from the displayed remaining capacity, or should it just knock off the 14 Ah. I say it is the latter. So as you say Peukert is a good predictor of usable SoC IF the present circumstances of high load continue until the battery is flat. But in reality, boaters don't use their batteries like that. Or those that do, find they have a very short battery life! Of the course the whole issue of displaying SoC is fraught in the first place, because if the SoC meter says you have 50% left out of 100Ah, whilst you do have 50Ah left if you discharge slowly, you have less than that left (before the battery is notionally flat) if you discharge quickly. Since the SoC meter cannot predict the future - the rate at which the battery will be discharged - it's display of usable remaining capacity is just a guess and assumes a slow rate of discharge. All the above of which reminds me how glad I am that we no longer have Lead Acid domestic batteries!!! Life is so much simpler now!

Ok fair enough on your first point. On your second point, absolutely not - as I have repeated said, it is definitely the case that far less useful energy is available from a battery when discharged fast, than when discharged slowly. It may be the case that the way in which the lead sulphate is deposited changes slightly, and it is certainly true that the reaction rate slows right down at the end. However having discharged your battery fast until flat, when you leave it for a while the battery recovers and more charge can be taken out because the reaction, although slow, can still occur. So I could accept "rendering it harder to react" but not "rendering it unavailable to react". But I think the key point of interest is your recharging one. Having taken out 1/2 the Ah at the two rates, allow settling time, and then recharge both at a fixed rate, the Ah required to recharge will be the same (other than a tiny difference caused by increased gassing at the faster discharge rate).

The first half, I agree with of course. The second half once you start referring to Peukert, is a bit confusing but ultimately Peukert describes "lost" Ah as a result of discharging fast. This is only applicable if you intend to continue the discharge until the battery is notionally flat. What both of you seem to be doing is conflating Peukert, which describes lost Ah (Ah not in any way being a measure of energy), with useful energy lost during fast discharge from internal resistance (including reaction rate). These are two entirely separate concepts, one of which is wrong in the context of an Ah counting SoC meter, and the other of which, whilst correct, is also not applicable to an Ah counting SoC meter since that does not measure energy.

Gibbo you are wrong. The lost energy goes to heat. None of which is related to Peukert, which only describes "lost" Ah, not lost energy. There, can I get on with something more useful now? I am in the middle of a little project for a rotational position sensor, using a diametrically magnetised 5mm rod and my own design 3D printed housing, and my own design 25mm diameter pcb that is being made in china as we speak, with a 2 axis magnetic sensor chip that can send data over I2C. I didn't really know that you could get diametrically magnetised rods but that just has to rotate above the chip and the chip resolves that into angle. All very cheap and simple. And it might even work! 3D printers are great by the way, you should get one. It's the sort of thing you never knew you needed until you got one, and then you use it all the time!

I really commend you to watch the 3 Youtube videos I linked to, this explains the whole thing well, and is quite interesting. The point is that AmpHour counters do not need peukert fiddle factors to display SoC. They only need it to display "time to run" at the current discharge rate, which is not really a useful thing for boaters. How come amp-hour counters drift? It is simply the slight inaccuracy in measuring current and then subjecting that data to integration wrt time to go from current to amphours. Any process involving integration will suffer from accumulating increasing error unless the input data is perfect, which it is never going to be. That has nothing to do with Peukert. For boaters in particular, who tend to discharge their batteries at a very slow rate overall (20 hour rate or slower), Peukert is not relevant. Peukert only describes the (alleged) loss of Ah, it does not describe the loss of energy from rapid discharge. So in some ways you are correct, it vaguely describes a phenomena but using the wrong concepts and the wrong numbers, and an Ah counter will not reflect the loss of energy as it only counts Ah, and Ah is not a unit of energy. Perhaps you don't mind using completely the wrong ideas to describe a phenomena if the outcome is satisfactory? Personally I do, although I would agree that it doesn't matter too much in practise so long as you are not someone designing an Ah counting SoC meter. But it just offends me to see incorrect information repeated parrott fashion by so many people, when giving the right information is just as easy. Why not just give the right information?

Yes the Smartgauge was pretty good, even though he didn't handle the charging side of things well. He used a linear algorithm to increase the SoC according to charge voltage regardless of SoC, whereas we all know that it is not a linear thing. A bit lazy, really. But it was very good on the discharge side of things. That someone is helpful does not give them carte blanche to deny the basic laws of physics. And anyway he LITERALLY asked for an argument, so please direct your sympathy elsewhere! Actually I have a suspicion that he is younger than me!

?? Do you have any idea how lead acid batteries work? They convert chemical energy to electrical energy by a chemical reaction between lead and sulphuric acid that creates lead sulphate (yes the reaction is a bit more complicated than that, but that is the outcome). Lead sulphate has a lower energy state than the individual lead and acid. So far from converting into lead sulphate TAKING energy, au contraire it is that very reaction the liberates electrical energy. No more or no less lead sulphate is created by discharging x amp hours if it is done slowly or rapidly. One has to bear in mind that this started on another thread with Gibbo saying he wanted an argument. I am simply obliging. Don't hate me for it, I am just satisfying an old man.

But what real-life consequences does Peukert have for boaters? Please remember that no-one is denying that fast discharge of batteries gives less useful energy, but that is nothing to do with Peukert. It is only to do with the voltage efficiency of a battery (remember, Peukert has nothing to do with voltage). It is however a source of a lot of confusion and mis-information, and it is that which is my mission to dispel. You accuse me of putting theory above practice but I would say that if practice is contrary to theory, then that practice is probably wrong even though it may well have been common thinking for decades or centuries. The world is full of such self-perpetuating misconceptions.

You haven't shown anything, you have just repeated your myth with no evidence and no response to my challenge about the breach of first law of thermodynamics, other than to deny it. A battery is an energy store, the energy being chemical energy. There is a fixed amount of chemical energy in the lead and acid. Your hypothesis is like saying "here I have 2 idencial pieces of coal, if I burn this one slowly I get more total energy from it than if I burn this one rapidly". Pure rubbish. A capacitor stores energy in an electric field which as you say is different, but still an energy store

Yea but that was on Star Trek. Surely you can appreciate that if you discharge a battery fast, it tends to get noticably warmer. It has to, because there is finite internal resistance and with power being the current squared times the resistance, that power is dissipated as heat into the battery. Same as when you pass current through any resistor.

Yes the battery does warm up if it is discharged fast. Or discharged at all - just more so when discharged fast. Of course it has quite a lot of thermal capacity (lead and water) so the temperature rise for a given amount of heat is not massive. But it is certainly easily measurable.

Well there is certainly no confusion on my part. Neither Amp hours nor Peukert's equation have the dimensions of energy. In order to get energy from amp hours you need to multiply by the voltage at which those amp hours flowed. The reason why Peukert has to be specified in amp-hour counting devices is only for the "time to run" display. The SoC element should not have Peukert applied, for the reasons I've given. You are breaching the first law of thermodynamics (paraphrased as) "Energy cannot be created or destroyed, it can only be converted into other forms of energy". At the start, the battery had a certain amount of chemical energy that could have been extracted and turned into heat and electricity. By your hypothesis, depending on how rapidly you choose to discharge the battery, this fixed amount of chemical energy is converted into a variable amount of heat and electrical energy. So if you discharge fast, what happened to the part of the original chemical energy that has now vanished? Where is it? Hiding in Spain perhaps? Or been whisked away by your amazing powers of teleportation? No, it is has not because that would be a clear breach of the first law of thermodynamics. Try again. I gues this is one of the differences between us. A degree foundation, that you once scoffed at, provides the tools for this basic gross error checking. Hypotheses that flout the basic laws of physics fail at the outset, never mind the introduction of "logs" or other smokescreens, the hypothesis must be fundamentally flawed.