Tony1

Yes, no problem. This is the link Ian posted. As I understand it these (or something like them) will be introduced for the RCD certification,, but most people feel it is only a matter of time before the BSS also introduces some similar rules. https://cdn.standards.iteh.ai/samples/76438/9f817478349b4f4f8770642cb1748902/ISO-TS-23625-2021.pdf Thanks Nick, I was thinking about using the lowest power setting that moves about 35 cubic feet pre minute, but on reflection even that does seem a lot for a pipe of about an inch diameter. Does this look a bit more suitable? Lower power, and less than 10 CF per minute on it slow setting- and very low power usage. https://www.amazon.co.uk/gp/product/B0C4HSWBSZ/ref=ox_sc_saved_title_4?smid=A1OGRI65268WXS&psc=1

On the original issue of keeping lithiums warm when they've been banished to the engine bay, and pursuant to Nick's rather smart idea of using the warm (and free) cabin air, I've found this inexpensive and low powered fan. It screws onto the cabin wall and sucks out air through a downward 1.25 inch pipe- and then into the engine bay via some suitable ducting tube which I dont yet have. I am hoping it will push enough warm air from the cabin into the battery box that the lithiums will be kept above zero. Although I only see this being used on the odd very cold night, I could plug it in via a timer and set it to start at say 5am, and that way the battery box will be well above zero by the time I approach the kettle, and we should never get into the territory of the chargers being disconnected. https://www.amazon.co.uk/gp/product/B00ZRBCCV2/ref=ox_sc_saved_title_2?smid=A3NZ6AYGZT0ZJ6&psc=1 It just seems to make sense to use the freely available cabin air, as opposed to using power from within the batteries themselves, that will have to be replaced by running the engine, or using a genny. PS- if anyone knows a way to stop the deadly engine bay spiders from crawling along the pipe and into the bedroom, do tell. Some sort of non-return flap might foil the blighters. Also, if a pipe from the engine bay into the cabin is a safety issue (other than the obvious risk of being eaten by spiders), I'm better off finding out now.

Au contraire, mon ami. We have an idea of the question, which is roughly this: what are the rules that must be followed to ensure a safe installation of lithium batteries? Bearing in mind common sense, and that we are not living in the middle of a nuclear power station or a space ship. From the draft regs, I've already seen a few things which look more like advice about how to make your batteries last longer. Other requirements appear more suited to handling plutonium (or perhaps nitroglycerine) than lithium batteries. There are several things which appear to assume that LiFeP04's pose the same level of risk as other lithium types, which is patently incorrect. So as usual, the blinkered office-bound stuffed shirt jobsworths are already creeping the scope from essential safety into 'how to be nice to your batteries'. I'll be surprised if the title isn't 'Duck and Cover- how to survive an attack by lithium batteries'.

That sounds more like some kind of Ghostbusters sh*t. I bet you crossed the streams.

Maybe the BSS inspectors will never find out about it. They're not likely to go through the list of requirements from the cell manufacturers in order to verify that you've built the batteries according to the manufacturer's spec- or so you would imagine? And there's not likely to be specific checklist item about compression- at least not the in the first iteration of the regs.

That is my fear, I must admit, and yes it does seem likely they'll be forced to adopt a simplistic approach, if only from a lack of detailed knowledge. On the other hand, I maintain that with the use of victron components, I can demonstrate within a few minutes that my setup meets all of the BMS-type requirements in the (draft) regs. But if they really do refuse to sign off on any BMS systems that have elements of DIY construction, then there's not a lot us punters can do about it, except write off a grand or two, and if the funds are available, go out and buy fogstars or similar.

Depending on how strong the wording is around only using batteries or cells with suitable or recommended components, they might ask you for evidence that says your installed BMS is suitable for the cells you have. Also, how do they know your soldering technique is safe and effective, for example, especially if it has a slightly untidy appearance? I think the whole thing is a massive can of worms that will cause many arguments, much heartache, and a lot of wasted money, when it finally comes into force. I mean, there seem to be a couple of rogue inspectors even now who are strongly against the idea of an indoors install, which is just crazy. Imagine the arguments when the regs actually get published. Yes, I think there is a draft version of the proposed regs linked in that earlier thread called 'Solar dump'.

One has to hope that if one puts in place a system that will manage the functions that they specify in the regs, they will be satisfied- especially if you can demonstrate all of the functions. Modern BMSs like the fogstar have other functions, but it doesnt matter if those other functions are not part of the BSS requirements. But if a BMS is deemed non-compliant simply on the basis that it uses off the shelf components (as opposed to being part of the manufacturer's original assembly), that is effectively going to disqualify almost all of the DIY installs that are based on bare cells, which would be very unfair.

Just a quick (and optimistic) update, hopefully of use to those with DIY lithium installs using Valences or similar, and who are electrically challenged like me (which now that I think about it, is a tiny demographic): I think you will only need a single BMV712 and a single temp sensor to comply with most of the potential future BSS regs relating to BMS type functions for lithium batteries. A single BMV712 will use a single temp sensor to monitor and disconnect for both high and low temp events, in addition to the BMV's other features (high volt disconnect, etc). I've attached a screenshot of the phone with a temp sensor in operational use. This is assuming that BSS inspectors are satisfied with you monitoring voltage and temp for the battery bank as a whole. If they interpret the regs as requiring these BMS functions at battery level, then it might be more of a challenge. But it might be possible to place a temp sensor on each battery (about £25 each), and then attach all three of the temp sensors to a single BMV712 unit by simply stuffing all three sensor wires into the positive port on the BMV shunt. I dont know how the battery temp would display on the BMV unit, with three temp inputs active on its port, but the BSS types wont look that closely into it I bet. ETA- I do have a low SoC and low voltage disconnect set up as well, and these could also be done using the same BMV unit. I haven't done that with this unit, because in the case of low SoC or low voltage, I only want the loads to disconnect (and not the chargers)- so I've set up a second BMV and a separate disconnect switch to manage that. But that is not essential as per the coming future regs- I think it could all be done in compliance using a single BMV712.

My next logical step is gravitating towards the high-strength 'export' style lagers, and hanging out under bridges.

Sadly not old fruit. I sit firmly within the 'chav' demographic- in fact I see myself as something of a cultural ambassador from this much-maligned group. Crossing social divides, and all that. And of course, face down in the gutter on Saturday night.

Just a slight niggle old boy. Perhaps a niggle-ette. But in my ideal world scenario, at some point in the beer management process, I would quite like to do some actual tasting of the beer. I know- I'm nit picking, but... There is also the danger of one's partner having a few too many, and starting to throw objects at one. In my younger years I had a girlfriend who sometimes got violent after too much alchohol. Nights out were often lively, if a tad dangerous.

Yes I do. And I drink cheap lager with unlikely scandinavian-sounding brand names from LIDL (other stores are available). There. I've said it.

Call me old fashioned, but I do think I see the teeniest potential flaw in this otherwise admirable arrangement....

Normally I never moor near to a bridge or bend for this reason, but around Anderton there aren't many 14 days moorings, as you'll know- its mostly 48 hours. I found a decent spot, but it was heavily overlooked by high trees and a steep bank, and so I foolishly moved closer to a bridge/bend in order to get more sun for the panels, and because I was getting fed up with the interior being gloomy (as I have smallish windows). But on the plus side, with a 32ft boat there will be many good mooring spots in popular locations that one can get into, that a 55ft narrowboat cannot.

Thank Heavens they are finally taking the deadly danger of beer more seriously. Barely a decade ago I almost dropped a can of beer onto my foot. Had I actually dropped it, and had it actually hit my foot if I did drop it- and had I not been wearing slippers at the time this disaster nearly happened- then it would have damn near killed me. Clearly some sort of system is required to transfer beer from fridge to worktop without the dangerously unreliable and greasy hand of a human. I have some initial designs for a beer-loading system, which I will freely admit are derived from the autoloader of a T80 tank.

I do enjoy it when this topic is periodically revisited, as it is does give one a reminder of the pros and cons that one can forget, and its an area of interest for me too. One of the cons that occurred to me is vulnerability. I've been hit by narrowboats a few times in the last couple of years. The last time, near Anderton in May, was a really heavy ding on the hull side, and gave me a major fright. I feel sure it must be the biggest impact the boat has ever had. I can only guess what speed he was doing, but he left a visible dent in the hull side. I was changing clothes at the time, so by the time I got out, the offending boat had gone around a corner. It did occur to me- what damage would that idiot have done if I were in a GRP boat? Could the hull crack in some way under a 5mph impact from a narrowboat bow, hitting it at say 45 degrees? The other cons that I've seen mentioned are the lack of efficient electricity generation from the engine (if it has an outboard), and the lack of roof space for solar panels - obviously issues if you want to live aboard, not so much if you only do a few weeks cruising. My steed of choice would be the Viking 32cc or similar, with a very small SF stove and some kind of extra water capacity (I think the standard tank is about 25 gallons). Again, only an issue if you want to live aboard for longer periods and stay out in the sticks for longer periods. The rear cabin would make a great storage area, meaning it doesnt need heating very often. My impression is most GRPs can turn 180 in so many places that you dont have that occasional narrowboat palaver of going 3 miles in the 'wrong' direction to get to the next winding hole, just so you can turn around and go in your chosen direction. But if I still want to cruise and spend months living aboard in say 10 years from now, and if I feel I might struggle physically to manage an 18 ton narrowboat, then a 32ft GRP might be a good option. I suspect stepping aboard them might be a bot more tricky as they bob around a bit more, but pulling them to a stop or hauling them in against a strong side wind should be much easier.

Well not yet- its guesswork at the moment, but I'm fully expecting my insurance company to transpose the nuclear waste regulations into a new 'information document' covering the installation of lithium batteries, since as we know lithium batteries are currently the most dangerous objects that exist anywhere on the planet, and certainly the greatest threat to the future of mankind. I wouldn't mind if the next extinction-level event was caused by lithium batteries, as long as it took out those BSS b****rds who are turning lithium battery longevity and preservation advice into so-called essential safety regs.

I suspect there are many lithium users who don't have the benefit of the advice and experience on a forum like this one, and who routinely overstress their batteries. I spoke to a guy with a lithium bank at Llangollen in December- he was on the shoreline hookup and I noticed his SoC was saying 98%. On a day to day basis mine stay under 85% (maybe 90% sometimes), and I remarked that 98% was a high SoC to be reaching on a daily basis. I added that I had read that it might shorten their lifespan- and maybe worse. But he wasn't having any of it- not that he was rude or dismissive, but he was unmoved in his conviction that he knew these batteries well, and felt sure he was handling them safely. Fortunately there are usually safeguards that will protect ill-informed users from harming themselves or their batteries- such as high-temp sensors and high voltage disconnects, etc. Even a half decent MPPT or other charging unit will safely manage the battery voltage if set correctly, and will go into float mode (i.e. effectively stop charging) long before the batteries start to suffer any harm. I just hope that knowledge spreads quickly about managing lithiums conservatively and not pushing them too hard too often. All we need is a single LiFeP04 fire on a narrowboat, and before you know it the bloody things will have to be towed behind your boat in a titanium tender, enclosed by a lead lined blast-proof shelter that's been blessed by the Pope.

What?! You 'dring' twice? You inconsiderate monster. One dring should be enough for any competent cyclist.

Yes, I think you're right, the original BMV wire is thinner than 18AWG. If I do have to extend them out into the engine bay, my thinking is that by using a thicker wire, it would reduce the voltage drop. (But to be honest, the idea of me planning electrical things is akin to a 12th century monk trying to plan the space station.)

My plan is that the 50mm cable will run from the main fuse to a bus bar, then out to the engine bay and onto the pos battery terminal. The BMV pos control wires are tiny things, maybe 18AWG. They run from the BMV shunt (which sits on the main negative cable run), onto either the pos battery terminal (M8 in my case), OR if I can get away with it. they'll sit on the same bus bar or post as the 50mm pos cable. I'm afraid I'm not describing it very well!

Cheers Nick, I'll give it a go and see how the voltage varies in different scenarios. I already have a conundrum anyway, in that I have three BMVs wired in sequence, and they all give slightly different voltages and SoC readings etc. Understandably I guess, because each BMV and shunt will take a small amount of current itself. For day to day use, I use the BMV whose values compare closest to the 'true' readings that you get when linking the batteries to the PC. No problem in my case, as my BMS is basically the BMV712s, combined with disconnect switches! I understand that the BMVs dont use voltage when displaying SoC, as Nick says, so that shouldn't be a complication in this case. I dont love the fact that because the voltage curve is so flat, I might voltage readings that dont seem to correspond well with the calculated SoC, but hopefully over time I'll get a feel for any innaccuracies. When checking the batteries' SoC, I always read their voltage at the same time. So if I read a SoC of say 70%, I'm looking to see a voltage of about 13.20v. If there is a small load, I add on 0.01 volts for every 2 amps of load, so if the fridge is on and there is a 6 amp draw, I might see a voltage of 13.17v, and I add 0.03v to compensate for the load caused by the fridge. If the load goes above 10 amps it becomes difficult to compensate the voltage accurately, but when possible I always corss check the voltage against the SoC, just for peace of mind. And ultimately if I'm not happy with the voltage accuracy I'm getting, I'll have to re-site the BMV wires onto the battery terminal itself, but fingers crossed I can get decent readings at the end of a long 50mm sq cable...

A quick query for the electrical wizards, if I may: I use BMV712 units to monitor battery voltage, current, SOC etc. At the moment the positive wires from the BMV shunts are placed on the positive terminal of the battery bank. (I think its referred to as the 'most positive' terminal as its the first battery in the row, and where the pos cable is connected.) When the batteries are moved to the engine bay, my first thought was I'd have to move the tiny pos wires from the BMV shunts out there too. And to reach out there, I'd have to add 3 or metres to their length. So here's the question- do these BMV shunt wires really have to be be sited on the pos battery terminal? Or could I place a bus bar (or post) on the end of the main pos cable that leads out to the batteries, and site the BMV wires on that? Would the readings they make still be usable, if they are sited at the end of a 4 metre run of say 50mm sq cable coming in from the battery positive? Would they show voltage readings that were lower than the true reading at the actual battery terminals, and if so, would it be a consistent drop that I could sort of compensate for? And if I run them out into the engine bay, would lengthening them by say 3 metres also make the voltage readings artificially low in some way? I've got to lengthen the temp sensor wires anyway, but they are more simple resistance based, so I'm hoping their accuracy wont be affected too much by adding length to their wires.

And this from the man who suggested using lead acid battery cases to house lithiums, and putting labels on them saying "Definitely Not Lithium". You are on very thin legal ice sir. (Do they actually sell those though? A friend was asking)