Tony1

If you have a reliable method for obtaining the services of such a creature, do please PM me with the relevant details. As far as I know, many of them have their own little hobby horses that they like to focus on, and if I get the bloke who treats lithiums the way a 16th century peasant treats a suspected witch, I've had it. Cheer Nick, I was beginning to suspect the cold thing was being overplayed a bit, but my concerns arose again after talking to that boater (and I do trust the guy, he seemed a very solid character and not prone to exaggeration)- and he was very clear that there were at least three boaters (in his vicinity) who hit temporary snags when it went below minus 9 last December. I guess what I'm pondering now is whether its worth installing insulating mats, or heated pads, or just on the bare steel.

The batteries would obviously love to disappear off to a warmer place, and I would love to oblige them, but alas there are complications. I did briefly consider removing the lithiums into a storage box on the towpath, and installing two crappy lead acid batteries to pretend I've never had lithiums aboard. But then they would want to know why I had three B2B chargers in the boat. So I'd have to rip those out, plus all the wiring... Then they'd want to know why I needed all those BMV712s, the BEP switch, the battery protect disconnect, etc etc. Maybe the approach I should take is to attempt the BSS with the lithiums and if the guy fails it, then I can rip out all of the current wiring (bar the MPPTs), then spend £200 on some cheap lead acids and set up a basic lead acid system to pass the inspection. Only a complete scoundrel would then put all of the lithium gear back in place a few days later, so I definitely wouldn't do that.

On the more fully featured BMSs that come with many new batteries, the heating will be activated at a set temp. E.g. on the Fogstar batteries, the temp sensor will activate the battery's built-in heating pad before it gets to zero. So you are using the battery's own energy to keep it warm. On external heating pads, a similar thing will happen. So that stops the batteries disconnecting. I dont have any of that on mine, but I can set something up to disconnect the chargers if the battery goes below zero. The loads that would power the heating pad, on my DIY system, will never be disconnected due to a temp sensor. The problem is that it does look as if some sort of fire protection is going to be a requirement for indoor batteries (and I've heard that coming from several directions now), so I figure I might as well bite the bullet and get them relocated. My thinking is that it will avoid any arguments with an over zealous BSS inspector who might try to fail the boat because my batteries are exposed to the interior (and there isnt enough space for a fireproof/steel box to be fitted about them). It would be a pain to fail, and then have to scramble to get the work done in the two weeks or whatever it is that you get to put things right before they recheck. And to be fair, people are not reporting problems with them in winter, so maybe its all fine...

The background to this query is that I've decided to move my lithium batteries from a warm bedroom cupboard out into the engine bay. If I remember it, there were about 15 nights last winter when the temp went below zero (I was on the Llangollen)- and sometimes well below zero. On a few nights it went down to -9 on the cut, and even by midday it was still barely above zero. I understand that its is ok to draw current from lithiums down to -5 or lower, which is very handy as I do like to use the electric kettle for a coffee on a freezing winter morning. But I am aware that charging lithiums below zero degrees can damage them, and I was curious about how lithium users deal with this issue on the very cold mornings that we occasionally get. I was talking to a boater not long ago about the positive attributes of lithiums, and he mentioned that on one of those very cold winter mornings he spoke to a few boaters who'd had problems with their lithiums. I didnt pick up on the detail of the issue, but I would guess the BMS in the lithiums disconnected the batteries when it sensed the very low temperatures, and I think this meant the loads were disconnected as well as the charging, so I presume the boats had no power. There are ways around this, such as heating pads, and I'm curious how much power these things use on the very cold nights, and whether they are considered worthwhile? Other folks have pointed out that if the batteries are placed directly onto the steel of the swim(?) plate (which seems to be the most common location), they will kept around zero at worst, because the water under the surface doesn't go below freezing (unless its apocalyptic freezing). So maybe insulation pads are counter productive? Do some people deal with the cold issue by simply running the engine for say 20 mins before they do any charging? So I've heard some people say its almost a non-issue, and I've heard a couple say they have had complications with lithiums on the very coldest days. With all that said, I'd love to hear the experiences of anyone who's cruised with lithiums in freezing weather.

This is great advice. The collective wisdom of the members here will point out scores of issues with any boats you like, that a single person wouldn't spot. Once you get to a shortlist of say 2 or 3 boats, you can post detailed specs and photos, and the folks here will highlight any red flags, potential fixes or upgrades needed, things to watch out for with the engines/electrics, and so on. You will get some hasty and ill-considered advice too, but hopefully people will comment on those posts. For me, a big question would be- is the boat intended for extended cruising trips, or full time liveaboard use? If its full time liveaboard you might want to give more consideration to energy sufficiency, solar panels, a powerful battery charging system, maybe lithium batteries, space for a washing machine, overall storage space available, and length of boat- the list goes on. But for extended cruising, those issues are not so important. Boat length is a factor, as you'll probably already know. If its longer than 60ft, some of the Northern canals will be off limits due to the size of some locks, for example. If its shorter than 50ft it may feel too cramped, and you may end up throwing your crew overboard. But in summary, I would say the folks here can advise you on the pros and cons of any given boats, and help you to form a shortlist of say half a dozen that are worth a visit in person. For a hands on assessment of the boats that you still like (after a visit), then you need someone with a lot of experience, and surveyors are too expensive to use them for say three boats. Its in that process where someone like Matty might be a real help. It may be worth paying for a surveyor on the final boat choice, because people say that the faults they find will often pay for their fee by enabling you to negotiate a price reduction, and it may save you some heartache and hassle too. In terms of the buying process itself, you may find it's simple enough that you can manage it yourself, especially via a broker. If you buy privately, then some advice from folks here about the risks and the appropriate documentation might be a real help. People do say that well-priced boats sell quickly though, and that looks like a lot of steps to squeeze into what you hope will be a fairly short time (before someone else snaps it up). So there's not going to be a rigid process, there may need to be flexibility if a very suitable boat appears at a great price. ETA- final point I would add is that the older you go, the higher the possibility that some fixing work will be needed (with exceptions of course). So more of the overall budget will have to be set aside for the post-purchase work that is either needed, or is very much wanted.

Thats not a bad shout David. Bit of woodworking involved so that would end up a bit of a mess knowing me, but the idea is sound, and I've been wondering about cutting out some sort of inspection hole anyway, in order to check the bilges regularly.

I'm sure that's accurate Mike, and what I think it points to is big fuel savings when charging lithiums compared to lead acids with a genny. Theo's figures were for 240 hours of real life charging over a 2 year period. If I may don my inspector Clouseau hat for a moment, I would say that 120 hours genny charging per year (or static engine charging, for some folks) is not indicative of a year-round liveaboard CCer (it looks like a trad style boat too, so probably not loads of solar panels either). It would be too tedious to delve into all the detail, so I sort of assumed he doesn't live aboard, and when out cruising he moves the boat a few times per week. Or if he does liveaboard, he cruises on lots of days. So its possible that the longer final charging phase for his lead acids was done when cruising, and the genny was a sort of backup if they hadn't been cruising for a day or two. If my wild guesswork is correct, then the genny might not have been doing too much of the final 20% charging phase. But who knows- all I can really say is that its more economical with lithiums! ETA- my assistant Cato has just pointed out that I'm year-round liveaboard, and I only do about 100 hours of static engine charging per year, so my cunning theory appears to be in tatters (like most of my theories, to be fair). I do have a million watts of solar panels though, there is that.

Apologies Tony, I'm a bit slow this morning- what figures are you referring to? I do have lithium batteries, but I think the OP has lead acid, and the odds are so does Theo. I do often make the mistake of not mentioning that my batteries are lithium, and they will have a different charging performance to lead acids. I would guess that about 25-30% of the 240 recorded genny hours on Theo were done whilst 'topping up' the final 20% of the lead acid charge, and at in this phase the charging current will have been reduced significantly, right? Whereas with lithiums you would get the full 60 amps (or whatever) until the genny is switched off. If I've understood it correctly, all that means the running costs when charging lithiums would be even lower than my very rough estimates.

I have a extra complication, which is that my shoreline/mains battery charger will only charge at 30 amps. If my usage is about 120Ah of charge per day, and if I get 20Ah per day from solar, then at 30 amps charging, I would need to run the genny for more than 3 hours every day, and that would be happening on about 80-90 days of the year. This is not a gas vs petrol issue as such- but in my case, to make any kind of genny charging worthwhile, I would have to get rid of my Sterling PCU1230 unit (which is very versatile and decent quality), and splash out a few hundred on a more powerful 240v to 12v battery charger. I would also look at a 2000 watts genny, which might charge at 80 amps or so, and that way I could get the days charging done in maybe 90 mins, as opposed to 3 hours. I really wouldnt want to have to run a genny for 3 hours every day, not even a fairly quiet one. I think the cost of a better charger will put me off genny charging for a while longer- but ultimately, using a genny must be better than running the engine, so I'll still be pondering it.

That looks like very good economy indeed. If you say that that the 5 litres of petrol ran it for about 10 hours, that's 240 hours running on 39kgs of propane. I cant remember what my last bottle cost, but I'd guess it was approaching £40. If you work on a sort of worst-case scenario of £40 per bottle, that's £120 total, for 240 hours- so 50p per hour of running, If you say a litre of petrol will run a 1000 watt genny for what- two hours maybe(?), then that's about 75p per hour of running, if you assume the petrol costs around £1.50 per litre.. Petrol prices go all over the place, and gas varies too, so cost comparisons are never going to be easy, but 50p vs 75p per hour has to be considered a very significant cost difference. But as Puffling pointed out, the warranty issue is a complication, and with a brand new honda genny, most people will stick with petrol and thus keep the warranty valid.

At the moment I have about 1.4kw of panels, and it would be difficult to fit more up there without significant compromises. My concern would be that the solar power is so low in the winter that even if I fitted twice as many panels, it probably still wouldn't power the fridge all day. Two times nothing is still nothing- well almost. And I'm not going to limit my mooring options to places where the sides face south and I can tilt them, etc. I'm just not happy living without the fridge in winter- at least not at the moment. But there's no space in my cratch for bags of food either. In winter it has several bags of coal in it, a trolley, mini washing machine, often some bags of garbage, wood pieces and paint tins from the current DIY project, plus whatever other gear I have no room for indoors. Its just not a nice place to put bags/containers with food in them. But I get why people switch their fridge off in deepest winter. Keeping it running probably costs me the more than half a litre of diesel per day, and that goes on for maybe 90 days. So there is a definite and significant cost, and I may revisit it in future.

Do you have any feel for the relative costs of the different fuel types? Gas bottles are not cheap, and I only have room for one in my bow gas locker and one in the stern locker, so accommodating a third would be a challenge- but worth considering if the economic case is there. If we say a 1000 watt genny uses 0.5 litres per hour, then a the cost of a gas bottle will buy enough fuel to run the genny for many hours- the exact figure will depend on the model in use. How many hours do you (roughly) estimate a small converted genny will run on a full propane bottle?

What are the economic factors of 1000watt vs 2000 watt gennies? E.g. a 1000 watt genny is more frugal, but if you want to run a 45amp battery charger it will not be running at idle, so the fuel consumption will increase- whereas the more thirsty 2000 watt genny will do the charging at a lower speed (one would think). Does it sort of balance out (so that their fuel use is roughly the same), or is one does one type use noticeably less fuel than the other? I've considered a suitcase genny several times, as an alternative to running the engine for battery charging in Dec and January (when there's not enough usable solar). But my Sterling shore power battery charger will only charge at 30 amps max, so in my case a 1000 watt model would be suitable. I dont fancy 3 hours of genny running every day though, which is what I'd need to get close to my absolute minimum 100Ah of usage per day in winter. Three hours running per day might need fairly frequent visits to the nearest petrol station, even with the maximum allowed size of jerrycan (I think the max allowed might be 20 litres for a metal petrol can). .

Hi Kris, I think it might help a lot if you can outline your approx budget, bearing in mind that maybe 10-15% of that total budget will have to be set aside for fixes and tweaks after you buy the boat. It may be that you don't need to focus on Springers so much.

I get the impression that a lot of the features required by this spec will be included in modern lithiums that have a good BMS. Although it does mention balancing as well, which I'm not sure is that common even on new lithiums. Buyers of bare cells, or of batteries without a comprehensive BMS, may have difficulties. In my case, I can meet many of the new spec's BMS requirements with my disconnect switches that are controlled by BMV712s, but one thing I don't have is a disconnect that will act when the battery is charged at below 0 degrees (or 5 degrees, say). In fact I dont yet have a temp sensor that will disconnect the chargers if the battery gets too hot, and that will be needed regardless of the new spec. But Victron BMV712s will work with temp sensors, so folks with DIY BMS setups might be ok. I think I'll need one BMV712 to manage the low temp disconnection (of the charger), and because of the way they work with the relays, I might need a second BMV to control the high temp disconnect. I actually have three BMV712s already, so I think its possible to add temp sensors to two of them, and connect the 12v signal from the BMVs to my battery protect unit. The battery protect currently acts as a high voltage disconnect for the chargers, so as long as I can wire in two extra 12v control wires to its input socket, I should be ok. So even with my rudimentary understanding, I think its possible for DIYers to use BMVs, motorised switches, and temp sensors to add in the control and BMS elements that are needed for the new spec, at battery level. But if these features are required at cell level, I'm personally going to struggle to meet them. @nicknorman, might I possibly prevail upon your knowledge of these beasties? can I use the victron temp sensor to control the relay in a BMV712, or can it only do an audible alarm? And if I can, would you use a relay that is NO, or one that is NC, for this sensor? https://www.victronenergy.com/live/temperature_sensors There isnt even a datasheet for the sensor, but I know from a youtube video that its resistance value falls as temp increases, if that helps? My first need is for a high temp disconnect for safety reasons, and I have a BMV712 already in place to disconnect the charger in the event of high voltage. The relay is not inverted, and its set to NO. Is that suitable to use with an auxiliary temp sensor for high temp disconnect? I think I have a feasible alternative strategy I could use, which is to use the remote BMS input on my B2B chargers. A 12v signal from the BMV712 triggered by a high temp event could switch the B2Bs and the MPPTs off, so no need to use the battery protect device for the high temp disconnect. Whether the BSS people would be happy with a remote charger switch off instead of a direct battery disconnect I'm not sure....

Thanks Peter. My batteries are a second hand set, originally designed for use in an EV, and with a separate external BMS unit that I dont have- so they have no internal BMS as such, although they have cell monitoring via an external PC, and a limited amount of balancing. I've set up some disconnect switches that are controlled by BMV712s, which act as the BMS in many ways. I think the batteries do have a temp monitor in them, but what they dont have is a means for me to monitor the temp in real time and stop the charging if they get too cold. If I can get them through the BSS (prob Sept), I'll see if a BMV712 can be used. I know the BMV712 will accept an external/auxiliary sensor, so in theory a temp sensor could be connected, but I dont think that auxiliary input can be used to trigger alarms and disconnects via the relay in the BMV712. But worth doing though. Once they are sited out in the engine bay they will be subject to minus temps frequently in winter, and if I start an early cruise on a winter morning, I'll need a system to automatically stop the charging until things get above zero in the engine bay.

I think if you had the phrase 'this is an information sheet' in an email from them, that might be enough to mount a legal challenge if they ever refused to honour a claim because one of those points was not fully met. But tbh the whole thing seems like a bloody mess for the next few years, as Ian says. That information sheet implies that you should mount lithiums on a fireproof base and away from flammable materials, so a standard install in a wooden box in the engine bay, and with a warming pad underneath, might make you non-compliant (if they were to push their case and dispute a claim). And that just seems like ridiculous overkill for LiFeP04 batteries. Add to that, it seems as if one or two BSS inspectors might be already starting to behave as if some of the future regs are already in place, so there'll probably be major inconsistencies in the way they approach lithiums for the next few years. As usual, its the bloody boaters who are going to get shafted, and have to fork out for unnecessary changes and work. I mean, simply banning the use of second hand LiFeP04 batteries just seems totally unnecessary to me. My insurance is due for renewal next month (craftinsure), so lets see if there are any information sheets or guidelines forthcoming when I renew.

I assume the insurance company would say that the boater did not comply with one of the rules of the agreement, therefore the whole contract was invalid. Doesn't matter which rule, or if the area of the boat involved in the broken rule was a factor in the fire or not.

Thanks for posting Rusty. Who are your insurers? If that list becomes common to all of them it looks disastrous for DIY installers- in fact some pro installs might be affected too. For example, not being permitted to charge near flammable material would rule out my indoor location for the batteries, as they are in a wooden cupboard- as does the requirement that you must charge on a fireproof surface. In fact people who have wooden boxes in the engine bay to hold their lithiums might also have a problem. (Do those battery heating pads count as a fireproof surface?) I'm not sure how you assure yourself in winter that you are charging above 5 degrees. I guess you'll have to state that you check the temp in the engine bay every morning, or before running the engine. I think rather than hit complications in my November BSS, I might move my batteries into the engine bay before then. Buying used batteries also seems to be ruled out, which again is a non-compliance for my setup. Its a bit of a sickener tbh, and it'll take them a couple of years of argument before they wise up that LiFeP04 are much safer, and change the rules to suit. It always seems to take three times as long to get a safety rule removed after its been debunked, than it takes to get the rule put in place. If all the insurers adopt these rules, then in my case it might mean having to ditch my current batteries (with over a decade of life left in them), and buying new ones- or else risk not having fully valid insurance in place, if a disaster strikes.

Oh no- I'm not going to get extra homework am I? 😀

It sounds like once the initial ignorance and suspicion have subsided, the regs might be relaxed to suit the lower risks of lithiums. It seems to me that it might be wise for DIY lithium installers to get their BSS done before those new regs come into force, rather than have to meet a whole new raft of requirements. I heard one comment that inspectors might require evidence that lithiums were professionally installed, for example. If that is even close to being true, its going to effectively rule out any DIY installations at all.

I totally agree that these regs are going to cause some major trauma for DIY lithium installers. For one thing, buyers of used batteries like myself dont have a fully detailed manufacturer documentation and guidance on installation and operation. I do have a data sheet, which I guess is better than nothing: https://www.lithionbattery.com/wp-content/uploads/2019/12/Valence-U27-12XP-Data-Sheet-210623.pdf I also dont have any invoices, specs or other proof of the install work that was done by boat electricians, and in any case 60% of it was done by me. My BMS is effectively a pair of BMV712s, which will disconnect the batteries and sound an alarm in the event of extreme high or low voltage, but I'm not sure the alarm is audible to a steerer. In fact, if the engine is running I would very much doubt it. It could be a nightmare for me trying to meet those regs, but my hope is that if I get the BSS completed by November, the new rules wont be in place, and I'll have 5 years to put something in place that will meet the coming regs. I've gotten an impression that there is some degree of memory effect with my batteries, but it doesnt seem to be extreme. I spent most of the summer of 2021 with the batteries between 60% and 85% because there was so much solar they never got discharged much, then in the winter when I started cycling at lower values, I did notice some slightly unusual behaviours on the first discharge that took the SoC below 30%, in that the resting voltage didnt seem to correspond very well to the SoC. But that said, it didnt last very long. But I recall Nick saying that it was better for the longevity of lithiums if you periodically give them a stretch, i.e. a full cycle between 100% and 5%. I dont think I've ever gone down to 5%, but I do try to give them a full(ish) cycle every few weeks at least.

I must apologise as I've said this before somewhere, but maybe worth repeating: I was in a marina chandlery a few months ago and explained that I would be looking for a BSS inspector later in the year. The person behind the counter gave me a business card and said this person was someone they knew who had expanded his general boat repair/maintenance/gas work into providing BSS inspections. "So he's new. Is he likely to be very keen then, do you think?" "Oh yes" they replied. "He'll be keen as mustard doing his inspections" As always, I was polite. "Great, I'll keep him in mind" The business card went into the bin as soon as I got back to the boat.

I absolutely agree with you, but I think the key thing is not to get into a dispute like that in the first place, by very careful selection of your BSS inspector. Someone kindly gave me a name in the Northwest but I cant remember where it is, so I'm still on the lookout for a BSS inspector who isnt hostile to the idea of lithiums, and who wont try to look for an obscure regulation to deliberately find fault. I had a chap in recently to fit a new dripless stern gland seal, and when he saw my batteries in the bedroom he said "that would be a failure if it was inspected by xxxx", on the basis that the batteries werent held in a metal box of some sort. I don't know the regs at all, but it sounded a bit random.

I normally set a 50 minute timer on my phone when I switch on the immersion, but of course I did forget that once. But the batteries didnt flatten- the thermostat cut the immersion heating when the water got up to temp, so it sort of self regulated in a very rough way. Over a full day the thermostat would cut back in and out, of course, and run the batteries down, so if I switched it on and left the boat for a day, the batteries probably would get depleted, especially if the solar charging was poor. It really does need a timer as you suggest, and I have my eye on a one hour timer in to replace the ON/OFF switch. https://www.amazon.co.uk/gp/product/B0BCY2XBJW/ref=ox_sc_saved_image_6?smid=AKY3EFCGM0MJ6&psc=1 But I'm a bit reluctant to fit that, or anything else, until after my BSS is done in November. I've heard a couple of vague rumours about a couple of BSS inspectors 'not liking' lithium batteries kept indoors (without a metal cage or similar)- so I'm not adding any further tweaks for the time being that might give rise to them 'not liking' some aspect of the electrical systems.