Tony1

This does seem like a very rare malfunction, and I'm not personally convinced (yet) that its something I need to take action on. But if I did want to build in a layer of protection against high voltages coming from the MPPT, what sort of relay would do the job? The BMV712 can be used to control a motorised switch and physically disconnect the charging cable in the event of a high voltage event, right? But the BMV units act upon battery voltage, NOT the raw voltage coming from the MPPT. So in my case, the charging disconnect would not activate until the battery voltage (on all three batteries collectively) went above the 'safe' cut-off limit (currently 14.8v I think). In an ideal world, it would seem preferable to have a disconnect that acted at the MPPT end, right? Before that high voltage event even hits the battery? Is that a feasible thing? I'm asking more out of interest btw, this seems such a rare thing that I dont see myself spend hundreds on preventive gear.

Thanks Peter, thats very interesting. This is a further extract from that post: "The very first response from them was the Victron mppt caused this issue. They also immediately offered to replace the battery. They went on say the Victron mppt’s should be swapped for Epever mppt’s. Their explanation is that the mppt sent pv voltage to the battery damaging the bms and causing it to start fire. He stated that the 100/50 in particular is "poorly" designed and not recommended." I have two of the Victron 100/50 MPPTs that the battery manufacturer is slagging off, so it is of particular interest to ascertain whether there is even a tiny grain of truth in the accusations. Certainly I've had no problems in the 2 years I've used mine (daily), and I'm sure the same is true for many thousands of users. Whatever the truth of it, you have to consider that even if the MPPT did have a freak malfunction and sent too high a voltage to the battery, the battery's internal BMS should still have been able to disconnect it, right? The thing is, nobody is going to test this out (and thereby wreck their own expensive batteries), but it seems like something to keep an eye on, both for MPPT 100/50 users, and lithium battery users with built in BMS's.

Tbh its a combination of several things that pushed me into doing it. 1. I've heard from two different boat engineer guys that indoor lithiums are frowned upon by the BSS inspectors that they talk to. Yes, I know there are no relevant current regs on this, but it seems that one or two are already inventing their own regs in anticipation of possible new BSS regs in a year or two. And I don't want to get into any debates with the BSS or their inspectors. I just cant cant be arsed with the hassle. 2. Storage space is severely limited indoors, and even a few cubic feet freed up will be very welcome. 3. I have to move them anyway. They're on a shelf and I'm not 100% sure how strong it is against their considerable weight- especially if I have to add restraints and gear to secure them in position properly. So the ball-ache of a battery move has to be undertaken no matter what. 4. There are not too many reports by people who boat in winter about problems trying to charge batteries in the freezing weather. The issues there are seem to be kind of manageable. 5. Insurance companies are getting in on the act. Just today I went to warn the folks on the boat moored next to me that I might have to make some noise doing the battery move, and he told me he'd had a letter from his insurance company with a number of stipulations about 'lithium ion' batteries. ETA: 6. I'm hopeless with general electrical stuff, and competent boat electricians are stupidly difficult to find, and very slow to book. So my hope is to eliminate any electrical failure issues before I even show up, because it might not be possible to book an electrician to fix things in the limited time you get to remedy the faults before a recheck. And especially so for any faults that have the word lithium in them. It may be a fools errand, in that I might never be able to fully satisfy all of the regs that BSS or insurance people introduce, with my ex-EV batteries. We can only wait and see how things go- and tbh, if I have trouble with the lithiums this winter, I'll probably move them back indoors. Indoors is absolutely the sensible place for them, given their optimum temps etc- but until the BSS is done, they are banished to the engine bay.

As a brief follow up on the issue of lithiums in very cold weather, I discovered this very affordable heating pad on Amazon: https://www.amazon.co.uk/gp/product/B07Y5WPF7W/ref=sw_img_1?smid=A2GBL94B2O20KZ&th=1 Proper ones are hard to find and seem to cost significantly more. This is intended for people who grow plants in cold weather, but it is waterproof, and it looks like it might be worth a punt. My original plan was to construct a hot air duct from the (very) heated cabin into the battery compartment (all this bodgery will be done once the BSS is complete, of course). But the concern is that to date, anything that I devise bearing the Heath-Robinson trade name has failed miserably. This thing only uses about 20 watts, so perhaps 1.6 amps, and it promises to keep objects above it 6 degrees warmer than the ambient air temp, which will be enough on all but the coldest nights. 1.6 amps might not be ideal, but it wont even be needed on most winter nights. And on most nights you do use it, you would get away with switching it on at bedtime and leaving it running overnight. There will be those mini ice ages we get, where the heater might want leaving on for 16 hours a day, but that will be very much the exception. The only snag in my cunning plan is that it is mains powered, and I was told that using mains power in the engine bay was a potential BSS concern. So there is that. But if anyone has any definite info on this question, please do chime in with your thoughts. Even if your thoughts are that I might be killed in a raging inferno within 30 minutes of switching it on.

I do worry a bit about stability with so much weight up there, but to avoid running out I like to keep a stock of at least 6 bags, and I tend to buy 10 at a time when the fuel boat passes. I only cruise maybe twice a week, so I find it easier to get lots of coal when I can, and then I can avoid doing cruises on very cold days specifically to buy coal. That said, I was very impressed when I was passed at Hurleston last Autumn by a liveaboard couple who only had one or two bags of coal aboard. When I asked them why so little, they said they passed a place selling coal every few days, so they saw no need to stock up.

I do use two centre lines, but I do like the sound of having an eye on each side of the roof. I dont have a rail, but rather a ridge at each side, so I would want eyes welding on I think. Certainly sounds easier to use than fairleads. Maybe its time to learn how to do simple welding jobs....

I thought this too, which is why I only got 1400 watts of panels- when I could probably have fitted almost 2kw. But it turned out that the 5 or 6ft of free space around the centre roof ring thingy is really useful for storing coal- I can stack them two high and get ten bags up there, plus a couple in the cratch. I try my best to keep the two centre lines running through the fairleads that are fixed on the roof sides, and so the lines dont usually get fouled by stuff on the roof. But fairleads are of course open at the top as we know, so in locks etc the centre ropes can easily come out of their fairleads when handled from high above, and they do occasionally drag one of the coal bags around. So if I did have panels there, they would sometimes get fouled with the centre line no matter what I do (unless I fitted those semi flexible panels that don't need mounting frames). But I wouldn't put panels there anyway- the space is needed for coal.

Just on this - some people have hung on to their compost toilets (a more accurate name would be 'separating toilets'), and installed fast-composting tubs/boxes on their boat (usually cratch or stern). There's one called a 'Hotbox', I believe. Its not that these toilets are banned, you just cant put the solid waste into CRT bins, so you have to compost it yourself. There might even be a thread about composting toilets.... As for the water, don't worry. I've been drinking water from the water point taps for several years now without filtering, and I've hardly gone mad at all.

Heaven forfend that I should cause friction Mr M, but I think one has to have some degree of concern for matters electrical when buying/speccing a boat, because it could cost a lot of money afterwards to put things into an acceptable state. For example, you probably consider me to be the most effete and bourgeois scoundrel who ever lived, because I run my fridge throughout the winter (instead of storing beer etc in a box in the cratch like a normal caveman would). But there's the rub- some of us maniacs will insist on hanging on to some last vestiges of civilisation and luxury, amid the endless mud and the grey skies of winter- and it may be the OP is one of that sort. On a vaguely related note, I recall hearing of a chap who specced the largest calorifier available on a new build, and only afterwards realised that this meant he would have to heat up a much larger volume of water on a daily basis, and thus use a lot more energy (from whatever source).

Yes, that's right. Once we get to October the solar yield drops off, and I start finding I have to run the engine every other day to add some extra charge. By mid November, the solar in my case is so low that all I get is a minor top up from it. On some sunny winter days, IF the side of the boat is facing south, I can double my solar yield by tilting up the panels, but that's not common. Because I only need engine charging on about 100 days of the year, I dont mind running the engine to generate the charge- and more so because I've increased the charging capacity, so I can now charge the batteries at 70-80 amps. The significance of that is that the charging is mostly done within an hour per day, with a little bit added by the solar. If I was charging at say 30 or 40 amps and so had to run the engine for two hours or more each day, I would buy a 2kw genny instead, so as to save the wear and tear on the engine, plus extra servicing etc. Bear in mind that even one the days they dont move their boat, many people will still run their engine anyway for hot water (you could get it by heating water on the stove, but that takes longer), so in those cases it might make sense to make sure you have a decent engine alternator to do the charging. My engine alternator couldn't be easily upgraded because of the crank, so make sure the boat has a decent alternator, as Nicks said above. Many alternators that are rated at 100 amps can't deliver even half of that current on a prolonged charge, without seriously overheating.

Mr T, I can understand that some replies come off as being a bit impatient or brusque, but I would ask you to be patient. In their defence, you must bear in mind that the same question has been asked here not dozens, but probably hundreds of times, and after taking the time and trouble to respond hundreds and hundreds of times, the members advice is often totally ignored or answered very rudely. Not that you've done that here, but before escalating anything into a personal quarrel, do bear in mind that Tracy, Tony, Nick and all the others give freely of their time, their knowledge and their decades of experience, and although they do occasionally let impatience show a bit more than you might want, never forget that their advice will often save you a lot of time, money and heartache, and maybe one late evening in the future when you have a critical failure, their prompt advice might get you out of a pickle. You'll never find a more useful or valuable source of knowledge on all things boating, but sometimes initially there is a teeny bit of prickliness to adjust to. Tracy is a gem and a mine of info, so I do hope you can settle your minor tiff.

In terms of predicting my needs wrongly, I bought a petrol genny before I moved aboard, to provide a backup source of electricity generation. After 30 months of it not getting used and taking up space in the cratch, I gave it away. I bought a clothes stand/dryer thing, and again it never got used more than once. In summer I dry on the stern using a brolly-mate, and in winter I can dry some stuff inside the boat overnight (you keep the stove ticking over and a window ajar so there is no condensation). But I have to find a local launderette for towels, bedding etc. A month in, I realised I wanted a washing machine, and still do, but its not worth the hassle and expense of changing my kitchen layout, as my boat is only 50ft long and I cant afford to lose any kitchencupboard storage. My boat came with only diesel CH, and by early October I realised I was going to need a SF (or diesel) stove. By early November I was burning a lot of diesel and the boat was still barely comfortable. When it was finally fitted, the SF stove transformed the liveaboard experience instantly. I took a full size bike aboard, and soon realised in school hols/ summer etc, I was sometimes going to struggle to get it onto trains (and I had nowhere handy to store it on the boat), so I ended up with a folder. Then I realised that 16 inch wheels are not great on some rough towpaths, esp in the wetter months, so I changed bikes again. After a month aboard I realised the batteries and the charging system were basically rubbish, and I went through a whole journey with lithium batteries and the best way to charge them. Boat length is another thing- I thought I'd be fine living solo on a 50ft boat, but storage space is a constant challenge and a major hassle. I often have to almost turn the boat upside down to find a tool, or a length of cable that I mislaid a week or two before. Windows are another thing- I didnt give a thought to it when I first moved aboard, but after a few months I realised I needed more interior light, i.e. bigger/more windows. That's why people are suggesting trying a boat hire in late Autumn before you buy, Its only once you live on a boat that you truly realise what features and issue are important to you. I got plenty of my initial guesses right (about what I wanted), but a good number of my expectations and concerns turned out to be very minor, and some brand new ones cropped up.

Just on the energy point, from your details I'd say you'll probably be a 130Ah per day sort of chap, like myself. I have 1400 watts of panels, but 1000w will do an awful lot of what you need. I get enough solar power to be self-sufficient for about 9 months of the year, and in fact I get solar hot water for about 4-5 months of the year. Lithium batteries are brilliant (esp with lots of panels and a good genny or engine charging system)- but there is a feeling here that they may become subject to some new regs in future, so make sure the battery and charging install is fully compliant.

As someone who only moved onto a boat 3 years ago and still a relative newbie myself, I cannot stress strongly enough that the members here know what they are on about. Their advice is generally worth its weight in gold, and they will usually give you up to date, practicable and accurate information and advice on almost any topic you raise, provided you are polite and respectful in your approach (some new folks are not). Many times they will respond very quickly with great advice if you have an emergency. Please, please give due weight to their advice. As a newbie I was inclined to think I knew how I wanted things on a boat, and what were the important things, and I felt that I probably knew the best way to get what I wanted. In reality, I reckon about a third of the issues you think are important now will become very low priority within a month of moving aboard, and a whole raft of new needs and priorities will arise that you did not foresee. The gas thing is a great example- gas is used on almost all boats, but not because it's traditional or from sentiment- it is simply the cheapest and easiest way to get the huge bursts of heat energy needed for 30-60 minutes for cooking. The electrical methods are ALL more complex in execution, and much more expensive, and they will require running your engine or a genny anyway- which after 8pm is not really permitted. The gas bottles last five or six months (in my case), so its no hassle to keep a supply going. I do also get the attraction of having a new boat built, so that the engine and critical systems are all brand new, but you probably wont get afloat for about 18 months. That's 18 months of wasted boating time. In my case that might end up being 15% of all the time I have left whilst still fit and able to actually live aboard a boat. For a similar price to a brand new sailaway - plus all the materials you'll need to finish it- I bet you can probably get hold of a boat that is only a year or two old, and still in almost as-new condition. And you can be afloat within a few months, if you can find the right one at the right price. ETA- the prices for nearly-new boats vs brand new seem quite close, but the advertised prices you'll be looking at might not be what they actually sell for.

For F**ks Sake That's great news. So you're sure he's not dead?

Obviously you know we're all rooting for you old chap, and I think me more than most. Well more than Rusty is, anyway. But we need to be realistic about your chances - the fact is that it doesn't look good old chum, and we need to think about what will happen to that lovely boat of yours when if you pop your clogs. Obviously no-one would be more devastated than myself if the worst happens (certainly not Rusty, anyway). Terrible tragedy, etc. Honour the glorious memory, goes without saying, etc. But if you are torn about which of us is more deserving, ask yourself this- could you really leave your boat to a man who lets his wife drink all of the beer? Not just some of it, mind. All of it.

In fairness I did use the word 'might' in that highlighted sentence, so I'm not being completely definitive. But I think people really should know about and pay attention to these possible new regs. The implications could cost a lot of people a lot of money. I personally do think its more likely than not that they will insist on a pro install, or at least a pro inspection/sign-off. But they haven't even got the basic regs in place yet, so who knows when the 'pro approval' process could be implemented? I also think its likely that insurance companies might ask for similar things, and also boat surveyors. At the very least, I think there are enough warning signs that anyone pondering buying lithiums for a DIY battery build and/or a DIY install should pause for a year or so, and see how the landscape changes. I've had mine well over 2 years so at least I've had some decent usage, and I may get a few years more before hitting problems. But I've probably spent over £2k on my lithium setup, and much of that could be a complete waste if they rule out my DIY BMS system, for example. Its very concerning, and I would hate to think of anyone not taking the impact of the potential new regs seriously, and maybe wasting a lot of money they can ill afford on kit that has to be dumped a couple of years later.

There are two points I would mention on this. I remember the very diligent H+S folks at my old work collected stats on 'near-misses', as well as people actually being hurt- so this may be affecting their thinking about lithiums. But I think the main point is Ian's one- there is every sign they are considering data from Li-ion batteries (ebike type) and EV's, as well as LFPs, and lumping them all together. I would agree with you in doubting that there has been a single fire involving LFP batteries, and almost certainly none on boats. And there certainly wont be very many in future, because very few people will feel that lithiums are worth the major expense that might be involved in meeting the regulations.

Aha- but I have a cunning plan that cannot fail. My lead acids are separated from the lithiums by B2B chargers, so they are only actually connected when the engine is running and charging is happening. Tbh it seems likely that when the time comes to get a BSS done with the future rules, and if they raise a failure against parts of my setup (and bear in mind there's going to be a bedding in period whilst they get used to interpreting the new requirements) it might be simpler to replace the lithiums with cheap lead acids, and just accept that I'm going to have to do lots more hours of genny charging.

I imagine it will take the regulators 5-10 years to adapt the regs so that they become proportional to the actual risks involved with the actual batteries used in boats- as opposed to the batteries used in ebikes. So yes- anyone selling a boat with a DIY lithium install might well face an adverse comment or warning from a surveyor. My boat will hopefully pass in another month or two, before any new regs are introduced. And if we get more stringent lithium regs that I dont think my install will comply with, I'll simply remove the lithiums and replace them with a bank of cheap lead acids before selling the boat. All of my Victron charging and battery monitoring equipment will work equally well on lead acids (just change the charging profiles)- so the change back to lead acids would be very simple, and would cost less than £500. I'm certainly not paying for the best quality premium batteries from named/accredited manufacturers. And any requirement that there has to be a professional install (by a 'lithium-safe' electrician, say)- will instantly reduce the adoption of lithiums to a trickle, by pricing most would-be adopters out of the upgrade. There are probably many people who bought good batteries but did a DIY install. Surely they are not also going to be forced to get rid of them, just because the install wasn't done by a pro? Surely even the BSS wouldnt go that far?

Same thing happened to a guy I know- dropped his ebike battery over the stern on the Llangollen. Apparently a passing local observed his comical attempts to fish it out and went to fetch his rake, using which the battery was eventually recovered. Apparently it was totally dead, although apparently there were no signs of any lithium-based combustion as he feared might happen on contact with water (apparently this wasnt LiFeP04 but the more dangerous type). Great shame though, apparently- new batteries for that model cost £200, so he was well out of pocket. Apparently.

I agree that an issue worth bearing in mind. I'm no expert, but I can say that what definitely won't happen is air coming in through the flue. It seems likely that cold air will be drawn in through the various air vents. But to the main point- the one thing I find that is in great excess during the coldest months is cabin heat. The fire is always ticking over during the night, and on the very cold nights it is slightly above tickover, so to speak. I think there were maybe one or two nights last winter- even the minus 10 nights- when I felt I needed to sleep with a T shirt on. And even then I was a bit too warm. But from December to end of Feb, the cabin is always, always warm. In fact, many times its a bit too warm, and the idea of sucking in some cold external air is not unwelcome. I dont think this fan will make a noticeable difference to the internal cabin temp- but I'll see how it goes, and if it does seem to cool things too much, I'll add a couple of extra coals to compensate for it. I may even appreciate it, as it will suck the warmer air down from the stove at the front of the boat. But Its a tiny thing really, and being USB powered, you have to wonder what it will actually do, if anything. USB can struggle to power a small desk fan.

It's what you do with the chisel....

I met a boater who had a 3D printer aboard and it looked like a really useful bit of kit, but I've no idea where I'd store the thing on a 50ft boat- I already have to to practically dismantle the entire vessel to find a long unused chisel or a box of washers.

Cheers Nick, and yes I did wonder about the power usage, as it doesnt specify. But then its USB powered, so I'm thinking its very likely to be low enough power that it can be left on at least from say 11pm till 7am. They've only got 3 left and I've not seen anything similar (with a round pipe outlet which is much easier to fit ducting tube onto), so I'll take a punt on this one.