nicknorman

We would need to know the recent history in terms of charging and discharging. Bearing in mind the voltage started out at 12.56v this could have been following a short period of charging and the decrease to 12.36v is just the dissipation of surface charge. In order to be sure I think you should fully charge the batteries (14.4v until the current has fallen to 2% of capacity, which will take many hours) and then let them rest for a few days.

Yes that’s the one!

No I don’t think the background fits. Although I don’t have a better suggestion!

Hopefully not. Water from dehumidifiers is full of dust particles and other airborne contaminants. Not great for batteries.

That can’t be right. Never believe everything you read on the internet! For every litre of (liquid) LPG burnt, aprox one litre of LIQUID water is produced. Which of course as a vapour has a much, much greater volume.

Is that the reason, I wasn't sure? We have a large range cooker at the gliding club, it is definitely not going to fall over. But it is chained to the wall. I wondered if another reason was to stop stupid people pulling it right out and stretching / damaging the flexible gas hose? If you have to undo the chain you are going to notice the flexible gas hose.

Yes. As long as they are explosion proof of course! Anyway I am just repeating what the BSS guidance says. Don't shoot the messenger!

Our ZWC1300 didn't like starting when on Travelpower power, but it was quite happy to start on the Mastervolt Mass Combi. So we would start it, then switch over to the Travelpower. Although these days with the Li batteries we don't bother, just run it from the Mastervolt Combi. The Travelpower is only used for the tumble drier.

I only got 1:20 in before he spouted bullshit. Although I agree that he is mostly OK.

Who knows what an examiner might think. But some would. The text does say open flame or spark inducing equipment. It is a long way from an open flame to a lump of mild steel. And spark inducing equipment suggests to me equipment designed to induce sparks. A lump of steel is not "equipment". Although I would agree that the list is not exhaustive.

It would depend on whether the steel slabs were restrained eg by being too big to slide into the cylinders,mbeingnunder the cylinders etc. I would disagree that some lumps of mild steel could create gas-igniting sparks. Have you ever tried to light a gas burner or even create a spark by clashing lumps of steel together at the sorts of speeds (accelerations) likely to ensue from a canal boat collision?

Yes it is safe to keep old AGMs in situ. I don't think BSS says nothing else can be in gas locker, what it does say is nothing in there that could either block the vents or move (in a collision) and damage the gas installation.

I can't answer your question, however whilst it is nothing to do with the licence application, a by-law does make it illegal to run the engine in gear when tied up. By-law number 38 in the 1965 bylaws which as far as I am aware are still valid. Whether breaching the bylaws is a reason to revoke a licence is another matter. Probably not, even though it should be for repeat offenders. And also of course it is a selfish and stupid thing to do.

My one from 2010 came with 175A. I am not sure when it changed.

Later Beta 43s (by which I mean in the last 13 years or perhaps older) have at least a 175A alternator as standard. 120A is about right for max continuous output without getting too hot. And as said, around 1200 -1300 rpm for charging.

There are a number of different things at play 1)Yes it is better not to keep the batteries fully charged. 2)The charger uses some power just to run itself (not much, but some) 3) Li battery life mostly depends on the overall amount of charge put in and out. So cycling the battery down to 20% and then fully charging, will wear it out faster than say keeping it around 80% and using shore power. 4) Although the charge efficiency of Li is very good (Ah in and Ah out virtually the same), the power efficiency less so (Wh in and Wh out) - although still much better than LA. So running direct from shore power uses slightly less energy than doing so via the batteries. 5) Taking energy only from the shore means you are not benefiting from the solar. So I don’t think there is a right answer, it depends on your priorities. One thing to consider might be to reduce the charge voltage on the Victron to about 13.3 or 13.4v and leaving the charger on. The batteries will settle around 50-80% giving headroom for the solar to add more on a sunny day and thus the Victron will charge less. The downside being that if you need to charge in a hurry, you would want to put the voltage back up to 14.4 or some such. So another factor is how easy is it for you to change the Victron charge voltage.

I spoke to Ed Shiers recently, unfortunately he is concentrating on his Li install work and doesn't do the Travelpowers any more. He recommended G E Middleton in Manchester

A picture of the actual thing called "Split X" would be good, but most likely it is a Sterling Pro Split R. The general idea is that it is an intelligent battery splitter that combines the two alternator outputs and direct the charge to where needed - at the outset, to the starter battery. Then when the starter battery is charged (normally pretty instantly unless there has been a problem starting) it directs charge also to the domestic batteries. If the domestic system drain is such that it is in danger of discharging the starter battery, this is isolated. Or if the starter battery is low, the domestic battery is isolated and the charge goes to the starter battery. When the engine is stopped, the starter and domestic batteries are isolated from each other. Overall, although it seems a bit overly complicated, I think you might as well leave well alone assuming it is all working properly.

It is a bad idea but I don't think it's a BSS thing. Even so, when you have those rubber boot things on it is easy for them to fall off or at least not totally cover every mm of live metal.

Google AI, which of course gleans its information by trawling the internet, provides this opinion, which aligns with mine more or less. I asked it "does holding a lifepo4 cell at 3.65v for long periods shorten life" Yes, holding a LiFePO4 cell at its maximum charge voltage of 3.65V for long periods will shorten its lifespan. While 3.65V is the correct charge termination voltage, it is not the ideal voltage for extended storage or "float" charging. Why High Voltage Shortens Life Increased Cell Stress: Storing the battery at a high state of charge (SOC), which corresponds to a higher voltage, puts continuous chemical stress on the cell components, particularly the cathode structure. Accelerated Degradation: This constant stress accelerates the chemical degradation processes within the battery, leading to a permanent loss of capacity over time, a phenomenon known as calendar aging. Reduced Cycle Life: To maximize the overall number of charge/discharge cycles the battery can perform throughout its lifetime, it is better to operate within a more moderate voltage (and thus SOC) range. Recommended Practice For general use and maximum longevity, experts and manufacturers recommend the following: Charging: Terminate the charging process at 3.6V-3.65V per cell using the Constant Current/Constant Voltage (CC/CV) method, and then remove the charging current completely. Floating: A traditional continuous "float" charge is unnecessary for LiFePO4 batteries. If a float setting is used, it should be a lower standby voltage (around 3.3V-3.4V per cell) which only triggers a re-charge cycle if the voltage drops significantly. Which is what I always say. Charge to 3.65 (or a bit less if you are not desperate to get every last Ah out of it) and once the current has fallen to 5%, STOP CHARGING! For the maximum cycle life if using all the capacity is not needed, mostly don't charge to 100%, but charge until the battery starts to "climb the knee" at maybe 90 or 95%, and then stop.

Fogstar BMS has a "balancing start voltage" which allows you to set the voltage at which balancing starts (as well as the delta v to start balancing). As we know, you don't want to set this too low as balance differences can reverse as the knee is climbed. But I think you could reasonably have it at 3.55v which means that you only have to go just over that for balancing to start. There is also a setting to say whether to only balance during charge, or to continue balancing after the charge voltage is reduced/removed. That is set to the latter by default. Also the BMS SoC estimation is not just a current integral and therefore doesn't have the slowly increasing without limit error that it otherwise might. It uses a table of cell voltage vs SoC, so the SoC estimation is a hybrid of that and the current integral. I think it is this table of voltages vs SoC that is not properly populated on delivery, hence why you need to cycle it a bit for it to "learn" the entries. You can manually set them as well if you like. I'm sure you won't have damaged them at 14.37v for many hours. One should bear in mind that Fogstar don't make cells, almost certainly haven't done any tests to support their opinion, and that the science is a bit vague, but I think that holding them at 14.37 for a long period - by which I mean weeks or months - is going to shorten the life. As is taking them up to 14.37 every day without any significant discharge in the meantime. But I don't really know, there is not much rigorous evidence out there other than opinion, but the opinion seems to be shared by the key players in the early adoption of Li, and there were examples of expensive Victron etc batteries wrecked by prolonged exposure to the maximum voltage.

If you want to get 100% SoC then yes, you need 14.6v. But if you go for 14.3 or 14.4v you still get 99.something% and personally I don't see the need to stress either yourself or the battery by ramming that last Ah in. If you charge at 14.3v, virtually nothing is lost and if the cells are out of balance, the balancing algorithm will still be invoked. I think there is slight confusion between balancing the cells within a battery, vs balancing two batteries in parallel. For the latter, the shape of the charge curve with its "knee" means that if both batteries are at 14.3v, they will be at the same SoC give or take a very small % (less than 1%). It might be that the internal SoC estimations are not identical, but that doesn't really matter as it is just the indication, not the reality. The BMS parameters can be adjusted so the SoC estimation resets to 100% at a voltage quite a bit below the maximum cell voltage of 3.65. I can't remember what mine (Fogstar) is set to but the BMS doesn't struggle to reset when the batteries are reasonably close to, but not at, the maximum allowable SoC. Setting a lower voltage just makes it take slightly longer to get to full due to the soft regulation of the charger, but the difference between 14.3 and 14.6v is negligable. If you go down to 13.8, then yes it would make quite a difference and would not be appropriate for charging with a generator or engine, if the aim is to minimise engine running time.

In my own boat, before we got the Li batteries, I installed a Mastershunt (blind Ah counting SoC meter) - shunt in the negative but also has a built in 500A megafuse in the positive. So I felt smug about that -well until we installed Li and now probably the fuse's max interruptable current is exceeded! So I am inclined to agree with you but on the other hand, how many serious issues have there been as a result of an alternator cable shorting the battery out? As I said, you have to look at the risk which is consequences x probability.

Convention says no. I agree that there is a danger from short circuiting the battery via thick cable and 1000s of amps, but in reality such cables are short and routed carefully. For example take a look at the standard wiring for the ubiquitous Beta 43 - there is no fuse between alternator and battery, just the battery isolator switch which can be turned off when working on the engine to prevent that pesky spanner short. Changing to Lithium presents an even more alarming scenario in terms of fault current, but also brings in the consideration that putting any old fuse in the wiring is probably pointless, unless the maximum breaking current of the fuse is taken into account. An ordinary megafuse etc probably won’t break the current in the case of a dead short on a big Lithium bank, it will just be arced over. But safety is about risk assessment and risk is the combination of severity of outcome and probability of it happening. Hopefully in a well installed unfused alternator system, the probability of a wiring short circuit is extremely low.

There’s a lot of communicational confusion between the participants in this conversation! If you want to charge to 100%, you first have to define what 100% charge means. Most cell manufacturers say that 100% charge is when the cell voltage is 3.65v AND the charge current has decreased to 5%. But then despite being at 100% charge, you could subsequently squeeze a tiny bit more charge in if you held the voltage at 3.65 whilst the current subsided further. But the extra charge, as a %, is tiny. This is the way to fully charge a battery is a fairly short time eg when running a generator or engine But does it matter what 100% is - not really because as long as you get quite close as in you 3.5something volts, you are not missing out on any significant capacity. You might be losing 0.5% worst case. The other way to charge is to apply a lower voltage for much, much longer. Days weeks or months at a time. 13.5v, given enough time, will get the batteries pretty close to 100%. It’s the sort of charging you might do from solar when there is not much taken out between days. Overall I thin you are overthinking it. What you are doing is fine - don’t fret!