nicknorman

February 3

5 minutes ago, IanD said:

Indeed, but that's due to the "soft limiting" curve of an analogue regulator. For hours of charging before the voltage gets up that high (which I thought was what Mike was talking about), surely both could provide the same current?

In my experience a standard alternator starts reducing field current very early in the voltage rise. I never actually measured it but probably as low as 13.6v. What I did notice was a massive difference when I went to digital regulation but still had the LA batteries, max current right up to about 0.1v below regulated voltage. But as I said, not of consequence with Li where the voltage remains very low until the end. Who is Mike?

February 3

11 minutes ago, IanD said:

I'm pretty sure it can't, it's just a regulator down from battery voltage like the internal one -- once there's full battery voltage across the field coil (which either can provide, near enough) that's it.

No but what it can do is put full battery voltage across the rotor when eg the output voltage is 14.1v and the regulated voltage is 14.4v. An analogue regulator will already have started modulating the field voltage (and hence reducing the current) long before then.

February 3

9 minutes ago, Tony Brooks said:

It depends upon how deep you want to go, and I suspect the Alpha Pro is actually a computer, a bit like a car ECU, measuring things like temperature, voltage, and possibly current to compare with a digital map it contains. that map MIGHT (but probably not) be adjustable by the user. It might also measure RPM, so it does not run a full charge a idle and stall the engine.

In effect, the until keeps turning the rotor field current on and off (just like a normal regulator) while altering the mark space ratio. Long ons and short offs give a high magnetic strength in the rotor, short ons and low offs gives a weak magnetic strength in the rotor. The strength of the magnetic rotor field and the speed at which it is moving controls the alternator output voltage, so long ons = a high voltage and low ons = a lower voltage. It may pulse the higher voltage to minimise gassing as the Adverc does, and it may also time the phase of charge.

It probably just boost the voltage during the acceptance phase of charging, so a little more current is pushed into the batteries, just like the Sterling equivalent or the Adverc. It can't do anything during the initial bulk phase because the alternator is working flat out, so the high current automatically depresses the voltage by careful design.

The Alpha pro is reasonably configurable via Masterbus. It can do temperature throttling (if you add the optional alternator temperature sensor), throttling at low engine rpm to avoid stalling or belt slip, and you can set an overall percentage of maximum output, which I suppose would be useful for charging Li if you didn't want to do it properly and have an alternator temperatures sensor.

1 minute ago, IanD said:

It can't get any more current out of the alternator, but if the alternator has a temperature sensor on (recommended with LFP) and overheats (likely with LFP...) it can/should reduce charging current to protect it.

What it can do is get more out of the alternator when charging LA at a mid-charge point, when a traditional alternator would have entered the large "between bulk and absorption" zone where current falls off long before regulated voltage is reached, due to a traditional regulator having simple analogue first order regulation. ie increase the current when the voltage has risen a bit but still a long way from the regulated voltage. Which is mostly what eg an Adverc does. But for Li, this aspect is not useful because the Li keeps the voltage depressed, hence max alternator output, until the Li is very nearly fully charged.

February 3

33 minutes ago, Anonathy said:

Thanks! I've been trying to research how it all actually works at a fundamental level so I've got a better understanding of it but everything online just seems to be AI generated garbage that constantly contradicts itself 😑 I wasn't sure if it mattered which brush was which but that clears a lot up. I'll just cut the ring tab off so it's definitely not connecting. I should be fine with the rest, fingers crossed, thanks for your help it means a lot!

It doesn't matter which brush is which because the rotor windings just create an electro-magnetic. Once it is spinning round, the stator coils (in which the current is generated) don't know or care whether one particular part of the rotor was north or south pole. I can't remember if I cut off the ring tab off or not, but I did keep the bush and I bought a spare regulator / brush unit from ebay for about £20, just in case anything happened to my regulator and I had to revert to standard. But 4 years on it has of course never been used!

February 3

It doesn't really matter which way round you connect the wires to the brushes. The main thing is to ensure that the brushes are not also connected to anything in the alternator (apart from the rotor of course). So definitely remove the brass spacer thing. I would keep it somewhere safe just in case you ever want or need to revert to the conventional regulator.

The thing to bear in mind is that you are effectively turning a 9 diode machine into a 6 diode machine. ie the whole field diodes / D+ terminal bit is no longer relevant. I know that the Alpha Pro manual talks about a "D+ lamp" but they are just using that terminology to mean "alternator warning lamp" - rather confusingly!. So the warning lamp is connected to the Alpha Pro as per the manual, nothing is connected to the D+ on the alternator. You will need to connect the W to the regulator though and also the "reg on" to the ignition switch.

January 31

As far as I can tell from you diagram, you are proposing just one fuse to run a number of services. The main problem with that is if a short circuit etc takes out the fuse, you lose a whole lot of other circuits that are in fact unaffected by the short circuit, and also you don't know where to start looking for the problem since several things have gone off. Not great when you are in the middle of nowhere in the dark. Or in a tunnel!

There can also be an issue with selecting the right fuse size since it has to be able to cope with all the services on, whilst not being above the cable rating of any one service.

I would also say that the further back towards the batteries you take the spurs off to the various services, the less wiring each service has in common and thus eg the slight dimming of flickering of lights when the water pump kicks in, is minimised. Or maximised if you have a lot of common wiring as you are proposing!

Normal practise is to have a fuse box/distribution panel close to the batteries, with each service independantly fused, and that is normal practise for a reason!

January 30

4 hours ago, Tigerr said:

We've always used Towergate Mardon, 25 years of different boat insurance. We've never made a claim.

There doesnt seem to be much difference in the cost between fully comp and third party, which I always find odd.

This year the renewal quote was a shocking increase. From £270 up to £344. Inexplicable.

I shopped around.

One quote was ridiculously high - £447!

But I also got a quote from Insure4boats, at £267. So I've bought that. It's the same cover, excess is half as much too.

Anyway, I thought I'd pass it on as I expect lots of others are being badly stung by insurance renewals.

Obviously I hope never to have to use it.

I hope it's not agains forum rules to post commercial stuff like this. I have absolutely no connection to any of these companies!

I had a quick look at their cover. It seems to me that you are covered for theft of your boat. But not theft FROM your boat, eg stealing stoves, batteries, even engines (all of which has happened) not to mention personal stuff of any sort.

We are with Craftinsure at £287, insured for 105k and with 3k personal possessions, and theft from the boat is clearly covered.

January 30

4 minutes ago, MtB said:

LFP are perfectly happy being kept only half or one third charged so don't actually need a 'half decent charge'.

Unlike LAs.

True, but 12v is a very low charging voltage and will only get them to about 10% SoC

January 30

20 minutes ago, MtB said:

But staying on topic and googling for recommended off-take rating for a 13kg propane gas bottle, its good for 15kW apparently. I'd have thought a good deal less!

It must surely depend on ambient temperature though. 15kw at a nominal 25C perhaps, but I bet it is a fraction of that at 0C

January 30

4 minutes ago, Tony1 said:

Thanks Nick- my sketchy takeaway from these discussions is that lithiums put out their charge at a voltage that is higher than the ideal operating range of typical diesel heaters, but it seems like its all nonsense.

Looking at the specs for the Eber heaters, they seem to have a minimum voltage of 10.2 and a max of 16, which is a pretty wide range. So 13.2v (Li) vs 12.5v (LA) is surely not going to be an issue. Most problems seem to arise from too low voltage caused by inadequate wiring / knackered batteries.

January 30

3 minutes ago, cheesegas said:

That's exactly my point. There is currently no qualification which defines what a capable person is in the eyes of insurance companies etc.

Personally, I'd define it as someone who installs according to the Small Boats ISO and BSS, and has had product-specific (eg. Victron) training if needed. Even still, the ISO isn't all encompassing on best practices, which have to be learned elsewhere.

And anyway, there are plenty of people with certificates for doing something, who are hopelessly incompetent. And plenty of people with no bits of paper to wave at you, who are great.

January 30

30 minutes ago, Tony1 said:

I dont know if this is a real issue for boat CH systems,, and even if it is, I dont know how serious it is, but I thought it might be worth posting just in case, as these units are so expensive to replace.

Coincidentally I had a problem with my Eberspacher last June, and I'm now wondering if it might have been a voltage issue (I started running the Eber from the lithiums about 2 years ago).

I've seen a couple of discussions like this on motorhome and vanlife forums.

Note- I'm not looking for a diagnosis on the Eber unit here, but I'm interested in whether anyone else has seen this issue on a boat when running their CH on lithiums?

And do our experts think it might be better to revert to running the CH from a lead acid/starter battery?

Or how about the voltage 'buck' gadget shown in the video below? And if that is the best/simplest solution, would a 10 amp model be enough, or would you need a 12 amp model like this one:

https://www.amazon.co.uk/gp/product/B08BRN3R5Y/ref=ox_sc_act_title_2?smid=A3FPBEEGWY9PJL&psc=1

https://thegreynomads.activeboard.com/t64679380/diesel-heater-voltage-issue

As I dont have any knowledge or expertise in this I wont be replying, but if there is an issue for lithium users to consider, our experts will hopefully discuss and define it between themselves.

This doesn’t make any sense to me. I didn’t watch the whole video but I think the gist was that a lead acid battery under charge gets up to 14.4v which is too high for equipment rated at 12v? But with Li, the charge voltage is usually lower so surely the problem is less? It’s true that Li discharges at over 13v as opposed to 12.something for LA, but if the equipment can withstand operating under charge from an LA alternator, surely it would be happy at a volt less when discharging with Li. I can’t see it being an issue.

Oh and I don’t know about Eber, but our Mikuni takes over 20A during initial light-up due to the glow plug current.

January 30

1 minute ago, David Schweizer said:

In my many past years of boating I have heard various reports of LA batteries leaking acid or gas, and someimes exploding, but have never had any experience of this happening in my boat, or indeed on any boat owned by friends. All this leads me to ask whether this is good fortune or better quality equipment and installation.

Or just an awareness of the issues? A boat came into our marina a couple of years ago and was moored opposite. It was an early electric hybrid boat with a lot of 2v lead acid cells and a fancy control and charging system. The chap had recently bought it. He plugged it into shore power and it was greedily hoovering up about 3kw. For several days😱

There was a hull outlet pointing at our boat, from which “steam” and gurgling sounds were emanating. This was the battery vent system. I pointed out the problem to the new owner, we checked and the batteries were too hot to touch. He didn’t really see the problem but I persuaded him to unplug it. A few days later it was plugged into shore power again and the same steam and gurgling. After a few people complained, he was asked to leave. Fortunately before it all exploded and/or sprayed boiling sulphuric acid at our boat!

January 30

9 hours ago, MtB said:

4kg/h is 56kW.

A traditional Morco or Paloma is 11kW running at full chat.

So 4kg/h is roughly five Morcos all running at full power together.

I still hold the limiting factor is the delivery capacity of the gas bottle not the rating of the regulator.

This of course being why heavy consumers such as fork lift truck engines, use a liquid take off from the cylinder. The liquid is evaporated using engine heat via a heat exchanger.

January 30

37 minutes ago, Momac said:

I think the DIY installation of lithium batteries perhaps should always be inspected and signed off by a suitably qualified person (in the same way that eg fitting of a gas appliance should be).

But what “suitable qualification” are you talking about? As far as I know such qualification doesn’t exist and correspondingly there is no requirement for one, unlike for gas.

January 29

1 hour ago, MtB said:

Long ago I was approaching a stricken boat in Blisworth. Even with my tunnel light on I could not see the actual boat even though I could see the SOS being flashed at me with their torch so we knew what to expect. When we got there they were so relieved we stopped instead of ramming into them! Didn't realise they had no idea we'd seen them, must have been terrifying.

Busted engine and we towed them out. All was well in the end.

It always annoys me when people seeking help or attention shine the torch in your face, instead of in their own faces so you can see what they want (and if they are likely to be knife wielding murderers). A few years ago on a winter's evening I drove past someone in the road shining a torch in my face, so I couldn't see a thing. I thought it was just someone keen that I didn't run them over (single track road). Fortunately for them I had to stop 100yds later to open the gate to the gliding club, whereupon a heard a weak and pathetic "please can you help me?". Turned out to be a young lady hillwalker who had got lost, didn't know where she had parked her car and had been wandering in the dark for hours, no food or drink (the gliding club is in the middle of nowhere in the Scottish Highlands).

I did explain to her that I had driven past because she was shining the torch at me, not at her, but I don't think she "got it" and was anyway too busy devouring a sausage roll I happened to have in the car.

January 29

This is an old piece from 2017, but well thought out and worth a read. Well, I thought it was interesting anyway!

https://nordkyndesign.com/protection-and-management-of-marine-lithium-battery-banks/

January 29

1 hour ago, blackrose said:

I called Frogspawn again today just to ask why my batteries have gone out of sync during discharge. Apparently it's fairly normal when the batteries are new until they've been through a few charge cycles.

However, when I mentioned that I would always avoid charging fully and triggering the BMS disconnect, the guy I spoke to said "Why?" He told me that I can rely on the BMS disconnect and that there's nothing wrong in doing that regularly. He added that it was designed to go through thousands of cycles and activate "thousands of times a second" (I didn't understand that part). Anyway, he seemed to think we were all worrying unduly - at least when it comes to Fogstars. No doubt he will be shot down in flames here - I have no idea who's right, I'm just the messenger.

One has to bear in mind that Fogstar don't build lithium cells and don't build BMSs, they just bolt stuff together. Certainly lots of people do fully charge the Li until the BMS disconnects and it is not disasterous to do so.

What is known is that routinely taking Li up to 100% SoC shortens its life (ie you get significantly fewer cycles when operating between 100% and 50%, vs between 75% and 25%). How much that matters is less well known. For us as leisure users, we probably only do 30 full cycles per year so the batteries are going to last longer than me (or die from calendar aging) even with some abuse. For a permanent live aboard IMO it would be more important to prolong the battery life as much as possible since there would be a lot more cycles per year. But certainly not essential.

Fogstar would still be looking at many years of service before the possibility of a warranty claim arose. But if you look at the Marine How To website (I think it was them) there was a lot of stuff about the early demise of very expensive Victron and Mastervolt Li batteries because of overcharging and relying on the BMS.

There is also a bit of a "failsafe" thing. I am not aware of what data there is on BMS failures and the failure modes (ie do they sometimes fail "always on") but it has to be a possibility, even if quite uncommon. That is why IMO it is better to have a charging system optimised for Li, and use the BMS disconnect as a last resort. That way there is some redundancy for what could be a fairly significant failure.

Plus of course this is what is required to satisfy the ISO on Li battery installs (I think?)

1 hour ago, magnetman said:

Also presumably that means when they say recommended charge voltage 14.4V this is correct and will not reduce the lifetime in cycles.

One thing which I do wonder about is are the 'cycles' recorded by the BMS. I mean is that how the cycle life is checked in the event of a warranty claim.

So is a 'cycle' classed as a BMS high voltage cutout? If it was then it would certainly be in the interests of the battery supplier to encourage high voltage cutouts.

What exactly is a 'cycle' when referring to the advertised specifications?

I know in this case @blackrose was attracted to the battery which advertises 8,000 cycles rather than a similar battery which advertises 4,500 so a cycle must somehow be defined somewhere.

I think we have done this one already and the cycle life is a function of the total kW h throughput.

No a cycle is not defined as a BMS high voltage cutout, it is defined as either delivery and receiving the rated capacity of charge, either cumulatively over several part-cycles, or 1 full cycle, or a % of that. eg some specifications might say "3500 cycles at 80% DoD" which would mean a throughput of 3500 x capacity x 0.8 Ah. For me, if it doesn't specify a DoD I would take it to mean 100% DoD.

January 29

29 minutes ago, David Schweizer said:

At the risk of hi-jacking this thread, may I please ask what are the benefits of replacing LA batteries with Lithium ones. We had two heavy duty Deep cycle US batteries in Helvetia, and they went on trouble free for years. They never ran down during usage and kept their charge consistently, they did not even require the electrolyte topping up for the first five or six years, and then it was only every few months (or more) when a small amount of de-ionised water was needed.

Like so many advances in technology, those who have not tried it, don't see the point. Those who have, do. It was the same when horse drawn boats went to having engines, when candles were replaced with electric light bulbs and even when my brain was replaced by an AI.

January 29

Just now, Stilllearning said:

I bought from Whilton and it was faultless, and a very good boat.

Heretic!

January 28

I suspect the problem is that there is still no clear info about what might be in the pipeline for the BSS regarding Li installs. A broker wouldn’t want their reputation tarnished by selling a boat only to have the new owner complain that it fundamentally didn’t comply with the latest BSS requirements. And as we know, Whilton can’t afford any reduction in their reputation!

I don’t see it as a big deal because if necessary, I could remove the Li and fit dreadful archaic LA for not much money as you’ve suggested. It would be a crying shame but there you go, some people find virtue in stifling progress. Not that we are planning to sell our boat anytime soon.

January 28

7 minutes ago, cheesegas said:

It's fine if you're on shore power, but LED tape is pretty inefficient making it unsuitable if you're off grid. The usual stuff has 60 LEDs per metre which equates to about 5w per metre. If you have a 3m saloon and use the tape on both sides of the boat, that's about 30w. Quite a lot compared to a couple of 4-5 LED dome lights!

It’s true that LED tape uses more current than a few led ceiling lights. But then again, a few years ago before led light became prevalent, 30w was 3 dim 10w incandescent bus bulbs. So it can be done! Our tape runs the length of the saloon, dinette, galley and bathroom corridor and uses about 5A (more like 60w) but then we have 600Ah of battery capacity so it could run continuously for 5 days, or 24 days running it for 5 hrs/day. The RGB controller allows dimming as well as colour control and we often have it on reduced brightness (less current).

Like everything else it’s a choice between the caveman lifestyle or the luxury flat lifestyle or something in between, but my hatred of ”in your face” lighting makes it a no-brainer!

January 27

25 minutes ago, Rod Stewart said:

Ours have been stuck under the gunnels for two years with the supplied tape, no problem. I was expecting it to come down in the first week, and did have my drawing pins at the ready, but didn't need them.

Ours were stuck on 10 years ago and still there. To be fair, we have plastic trunking tucked up under there and the LED is stuck onto that ie smooth surface.

January 27

Overhead LED lights can be quite harsh as they are not far above your head and quite bright points of light. Useful for reading, eating, cooking etc but rather unrestful for just hanging out. We have LED tape running under the gunnels throughout the main living area, and it creates a pleasant restive light that is not “in your face”. An added bonus is that we chose RGB (ie multicolour) LED strip, so we can set it to whatever colour we like. Cosy and restful! We only turn on the overhead led down lights when we need to see something in detail.

January 26

1 hour ago, BEngo said:

The variation is probably because the JBD SOC estimator is carp. Depending on version they use either cell and pack voltage or some coulomb counting plus cell and pack voltage to work it out. Unfortunately the output is not particularly accurate, except at full and empty states. The various clever shunts are much better, subject to an occasional alignment.

A disagreement between two BMS's is quite likely, and I would not be surprised by it.

N

Yes I wouldn’t pay too much attention to the BMS estimation of SoC, especially to start with. Even if the batteries were that imbalanced, which they probably aren’t, it’s of no consequence.

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