nicknorman
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Posts posted by nicknorman
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Just now, MtB said:
For there to be a sense of humour incompatibility, the other party needs to have one in the first place.
I was trying to be polite, you’ve blown it now!
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6 hours ago, blackrose said:
The only thing wrong with your post is that you think you can predict the future. I'm not saying that everyone will agree on everything related to using lithium batteries on boats, but I certainly think they're will be greater consensus as new batteries and new management systems emerge. I don't think that's a fantasy.
As I said, these days everyone more or less agrees on how best to apply "conventional" battery technology on boats and I doubt that was always the case. We didn't always have smart chargers or split charge relays for example, so it wasn't that long ago that many people weren't charging their batteries very effectively.
Basically you're all early adopters of lithium battery technology on boats which is why there are several different ways of doing it most of which don't seem entirely satisfactory. I can't predict the future either, but my hunch is that if I returned to these discussions in 5 or 10 years time some of these disagreements will have been settled.
Sorry, I had temporarily forgotten that my and your senses of humour are not compatible. -
35 minutes ago, IanD said:
The alarm doesn't have to be CANbus, a Bluetooth alert to a phone app costs far less, doesn't need any external hardware, and meets the requirements.
What exactly are the requirements? Anyone of engineering competence designing a warning system would not rely on the recipient having a phone, a phone that is on, a phone not selected to “silent” mode, a phone that has a non-flat battery and a phone that is currently running the relevant App.
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59 minutes ago, Roberto Conigliaro said:
On your first point - do you think that mixing the Li with LA would compromise the efficiency of the Li?
On your second point - I get it, it's not the 'right' way to do, but if enough people have done it and they say is efficient and safe (and I am not saying it is, just researching if it really is), the only issue remaining is passing the BSS really..
also in terms of costs, if a good 460ah Li is £1200 and 3 x 220ah AGM are roughly £1000, the difference is not even a big one
Well I am trying to understand if it's the case of one reckless person going for it or many who can say it is safe and sound. On the other hand, I get it, at the moment it's basically illegal..
what about there solution of going fully Li with s 60a DC-DC to protect the alternator, which seems to be not too expensive
I don't think the mix of Li and LA would significantly compromise the efficiency provided you didn't discharge the Li to the point where the LA starts discharging - which would be pretty low, probably below 10% SoC. This being because the Li voltage stays up around 13v or more until the battery gets very low. Effectively, there would be no current flowing into the LA during charge, no current flowing out of the LA during discharge. However I suppose if you were in the habit of putting on big loads like an electric kettle, this might dip the system voltage to the point the LA discharged a bit, and then you have the poor efficiency of LA recharging and difficulty of not being able to properly recharge the LA without overcharging the Li.
Also I suppose you would be holding the LA up at 13.3v and that might give rise to a bit of wasted current into the LA to compensate for self-discharge (something Li barely suffers from)
That said, a simple isolator switch between the LA and the Li would go a long way to making the "fudge" better. Switch closed when running the engine to recharge the Li, switch open to discharge the Li into the boat or if you need a long LA charge without overcharging the Li. But switches and people means finger trouble and at some point, having the switch in the wrong position! And potential to close the switch when the Li is very flat but the LA is full, which equals very large current flowing into the Li. Never underestimate the potential for human error to cause disaster!
Oh and I wouldn't say it is "illegal" at the moment, it just has the potential to become "illegal" in the future.
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1 hour ago, Roberto Conigliaro said:
yeah I see your point, from what I am reading here (thanks everybody by the way!), there are a lot of different theories and disagreement, so it might seem too much of a jump in the dark a this stage. Said that, energy efficiency is such in important part of life on the boat that I am gonna do more researches and hear more from people who did the switch, before deciding it isn't the right time for this investment, taking in consideration the pros and cons, financially and on a practical level
Energy efficiency is a good point. This is the product of the voltage and charge put in, vs that coming out. Both LA and Li have similar charge efficiencies (ie Ah out is about 95% of Ah put in). However when you take into account voltage, the energy efficiency of Li is much better because LA charges at 14.4v and discharges at (say) 12.5v. whereas Li mostly charges at 13.6v or less, and discharges at (say) 13.2v. And this is before you take into account the need to run an engine or generator for hours with just a trickle going in to get LA batteries up to 100%.
10 minutes ago, Roberto Conigliaro said:Well I just finished chatting with a person in another group who was saying that hybrid solution is the best : super safe and straight forward - just install a AGM batteries between the alternator and the Lifepo4 as a buffer and the trick is done. I feel like maybe some people would disagree with that, at least in terms of safety?
It works adequately and lots of people do it. It is reasonably safe.
However it is a bodge and may have a limited future because most Li battery manufacturers specify "do not mix with batteries of a different chemistry". And the BSS people don't like it and at some point it might (or might not) become a BSS fail. If you are non-compliant with BSS and have deliberately flouted manufacturers installation instructions, the insurance co are not going to want to pay out!
I explained earlier that although the batteries are fairly compatible and complement each other, the fine detail for long term is more problematic due to the differing charging requirements. So it remains a bodge that works after a fashion, but is not "the right way to do it"!
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46 minutes ago, IanD said:
Since the relationship between field and output current varies with battery voltage and rpm and temperature -- both ambient and as the alternator heats up -- it's actually a lot simpler to just measure the output current using a shunt and adjust the field current to set the required value (current demand), without doing any characterisation and curve fitting or relying on the belt not slipping.
If the controller also knows what the rpm is it then becomes trivial to do things like limiting the charging current (engine/belt load) at low rpm/idle, and if it knows what the alternator temperature is it can reduce the current demand if it gets too hot to stop it burning out when charging LFP batteries.
All this is what Wakespeed and the like do, because it's the right way to solve the problem 🙂
I disagree. Well I suppose the question is, why do you want to limit the current? Is limiting the current actually the aim (for example because the battery can’t safely take the full current)? If so then fair enough.
But in the context of Li batteries and narrowboats, this is almost certainly not the reason. The reason will be due to:
1/ avoiding overheating the alternator and/or
2/ avoiding overloading the engine, belt and or pulleys at low rpm.
In neither case does the actual current matter. What matters is how hot the alternator is, and how much torque is being applied to the alternator. Both these are best controlled by directly adjusting the maximum field current, not some convoluted mechanism to measure and then adjust the output current.
For 1: there is no direct relationship between temperature and current, it depends on ambient temperature and fan rpm amongst other things. Having a set limit to the field current allows less current at low rpm when the fan is going slowly, and more at higher rpm when the fan is going faster for the same temperature (roughly). Which is exactly what you want.
For 2, there is a direct relationship between torque and field current at a specified low rpm. Set a maximum field current, this sets a maximum limit on the torque to the alternator, which is exactly what you want.
We are not miles apart, but is clear that you have not designed alternator control software, and I have. Once you actually start writing the code, it all becomes clear and there is no need to complicate things by considering output current, when the more relevant parameter, and one that is already intrinsically measured by the control chip is field current. I was going to include a Hall effect current sensor in my design, before I realised it would be completely pointless.
30 minutes ago, blackrose said:Maybe I'll install lithium batteries when everyone's agreed on how to do it easily and safely while keeping my LA bank so I don't have to change all my charging equipment. To be honest I wouldn't really need my 70 amp alternator charging the lithium bank and could just use solar for that.
I've said this before and was shot down, but lithium battery technology on boats is obviously still in its infancy hence the multitude of different systems that people have come up with. Conventional battery technology on boats is so well established that everyone who's read a bit knows exactly what to do and all the experts are agreed. That's clearly not the case with lithium.
The only thing wrong with your post is that you have this fantasy that at some point, everyone will agree on how to do it. Never going to happen!!!
As you say, it is in its infancy. However the only sceptics are those who have not tried it. Those who have tried it would never contemplate going back to LA.
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6 minutes ago, Motters79 said:
Fair comments guys. I'm not entirely sure if the hose I've used would technically satisfy the BSS peeps, but I'm happy that it is suitable for the fuel used. I also understand what your saying about rubber hose on plain pipe, but in reality in this specific situation it could never come off the pipe through vibration or other means. It is a nice snug fit on the copper and with the jubilee clip done up you couldn't pull it off if you tried so I am happy that the job I've done is safe and secure. The BSS guy I use is also not a 'jobs worth' so I'm pretty sure he'll pass it. If not, then it's not beyond me to redo it when the time comes, but I seriously doubt I will have to. Please don't crucify me 😂
Well at least you used pukka fuel pipe, not just some random rubber hose from ebay! However I think the fire resistance might be an issue. The general idea is that in the event of an engine bay fire, the pipe doesn’t burn through and then pump diesel into the fire. It’s a pretty unlikely scenario of course, but the kind of thing BSS gets excited about! But as you imply, there are plenty of BSS examiners who are pragmatic. And of course some who aren’t! -
1 hour ago, dmr said:
Interesting observation about field current. I need to think about that but you will be correct. I think the Zeus can do field control too but I will investigate.
I am pretty much stuck with a 100 amp alternator on a single V belt so torque and temperature limits are needed.
The alternator shunt is a bit odd as it usually has to sit in the postive wire which makes the electronicss a tiny bit more difficult and means that the sense wires might need to be fused.
Controlling the field current is of course what any regulator does! It is just a matter of whether a max field current limit can be set. But this is what the various existing devices do (Alpha Pro, Wakespeed). With modern precise PID digital regulation, trying to control current by adjusting the set voltage is very difficult because very small changes in voltage make a huge difference in output current especially into Li batteries, and it varies with varying load. And if you think about it, an alternator is a current source not a voltage source, a regulator is a current supply not a voltage supply - the main regulation loop adjusts the field current to adjust the output current such that the output voltage is at the desired value.
So no point in complicating it by trying to control the output current via the output voltage which is controlled via the output current which is controlled via the field current. Just set a max field current (max duty cycle on the controlling MOSFET) and that is job done.
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1 hour ago, Motters79 said:
Yes assuming it was your lift pump that failed, which if it died in the same manner as mine then theres a good chance it is.
It's not too difficult a job. On my original pump they had cut the flared ends off and used compression fittings but I didnt wanna do that as i'd have to use a hacksaw and risk getting the swarf up inside the pump so I trimmed the copper pipe work back a bit (using a proper pipe cutter) and just used 8mm rubber pipe and jubilees as you can see from the pics.
The pump itself come off easy enough if you can get to it ok. I had to remove the lower 10mm bolt by feel as access is difficult on my boat. Hopefully you'll have a new gasket with yours. Mine didn't do I had to make one but luckily already had some gasket paper.
Good luck with it!
Ah sorry to be negative but this could be a bad idea. BSS doesn't allow ordinary rubber hose for fuel lines. It has to be marked as suitable for diesel and fire resistant. From the BSS:
Fuel feed, return and on-engine hoses must be marked, to denote both suitability for the fuel used and fire resistance, to BS EN ISO 7840 or an equivalent standard.
Applicability – hoses marked to SAE J 1527, DIN 4798 or RINA DIP/66/96 are acceptable.
Applicability – the presence of armoured or other external braiding is not evidence of hose suitability or
fire resistance. Such hoses must be marked as above.
Applicability – fuel-hose suitability may be supported by a written declaration from the hose
manufacturer or supplier or, if appropriate, from the engine manufacturer/supplier or mariniser. -
3 minutes ago, dmr said:
Yeah, it does CANbus, two shunts for proper alternator current limiting (which I need) and temperature control, it looks a bit like a bigger commercial version of what you did. Its very new and currently no UK agents so a hefty shipping charge, but I am heading in that direction.
and like you, it can use the state of charge from the Victron BMV to terminate charging.
...I am surprised that no "drop in Lithiums" give a simple 2 wire "enable charge" output.
Interesting that it has a shunt for the alternator current. Not sure why that would be necessary as one can calculate the current from field current and rpm to the necessary accuracy.
In any case, usually it is the torque load at low rpm that is the issue and this again is related to the field current, not to the output current. Same field current, same torque load, gives lower output current at low rpm and higher output at higher rpm. Or to put it another way, for the same current output, the torque decreases as rpm increases. So to adjust the torque load to match the engine output at low rpm, you just need to set up a simple max field current vs rpm function.
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Just now, Jen-in-Wellies said:
Single point of failure. Always a bad idea, which is the problem with the long wire, plus BMS disconnect only method.
This reminds me of helicopters. Lots of warning lights for dire things like tail rotor gearbox chip. But then you have to have a means to be confident that the warning system would work in the once in a lifetime actual problem, because if it didn't lots of people are going to die. So you make it failsafe ie if the system fails, the light comes on. And then because you are not totally confident in that scheme, you add a test button to simulate the gearbox chip and bring the warning light on which tests the bulb and all the wiring, and hope that decreases the failure rate to "extremely remote". But then with so much complexity, you are plagued with false warning lights. And you get so fed up with that, you start to ignore them...
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8 minutes ago, dmr said:
Victron do nice DC-DC converters with battery charging capability and about 90% efficient, but by the time you get up to 100amps or whatever the price is probably similar to something like the Arco Zeus.
Are two alternators a problem? just wire them both to the starter battery. As long as the voltage stays low enough to stop their internal regulators competing it should be fine. The advantage of something like the Arco Zeus is doing proper temperature control on the alternator.
No, 2 alternators are not a fundamental problem, but some rewiring would be required.
Just get the Zeus, you know you want to!
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37 minutes ago, David Mack said:
I note that different capacity batteries have the same case size. So do the lower capacity batteries for a particular case size just have more open air inside?
Different models seem to have significantly different lives. The 230Ah costing £700 has a life of 3500 cycles to 80% DOD, whereas the 280Ah version, £800, similar spec apart from the capacity and in the same size case, has a life of 6000 cycles. Why the difference?
The difference is probably how the cycle life was calculated. Guesswork by 2 different people gives 2 different results. With such long cycle lives, it all becomes a bit academic and depends on how it was cycled and under what ambient conditions. And calendar life comes into play as well.
16 minutes ago, Alan de Enfield said:But this hybrid system is the one the insurance companies are not 'happy with'
As @BEngo posted earlier :
The other cloud on the horizon is the BSS. They have asked the IEE to look at the electrical parts of the BSS, with focus on Lithium batteries (and 240 V systems). It seems that the review body are following in the footsteps of the USA's insurance led standards bodies and are not keen on mixed battery types ( hybrid installations), because a failure of the charge separator will lead to overcharging. Overcharging Lithium batteries increases the risk of a battery fire.
I seem to remember that @matty40s has previously posted similar information
No a "hybrid system" is where 2 batteries of different chemistries are directly connected together. It is unreasonable to consider a Li battery charged by a charging system that just happens to be assisted by another battery, to be a "hybrid system".
13 minutes ago, Alan de Enfield said:Just a thought - my car has a 170 amp water cooled alternator, apart from the price, would that be a suitable option for the high current, extended run times required by Lithiums ?
A vehicle alternator, if it is from a car built in the last 10 years or so, is unlikely to have a built in regulator. The regulation of the alternator is controlled by the vehicle ECU (engine control unit) as it adjusts the voltage according to what the car is doing (eg lower voltage during acceleration, high voltage during overrun or braking to recoup some of the energy) and according to the SoC and load.
So you would need an external regulator. Other than that, it would certainly allow for higher % of alternator load. There was a thread on here where someone had done that.
12 minutes ago, Alan de Enfield said:If you tailor the alternator output to suit the alternator (ie keep it at a lower level so it doesn't overheat) does that not remove one of the major benefits of Lithiums over FLA batteries ?
You would now need to run the engine for (possibly) just as many hours as you would for charging FLA's
No. For example our 175A alternator can run at about 125A continuously without getting too hot. When we had LA, the current would be below 125A after the first 5 mins or so, and then spend many hours gradually reducing with the final hours at below 20A in order to fully recharge and ward off sulphation.
With Li, we can put in 125Ah an hour every hour until 15 minutes before the battery is full.
14 minutes ago, Jen-in-Wellies said:The failure of any Lithium charger could lead to overcharging, since they are all separators between the input source and the Li bank. This would include mains, solar MPPT's, or even alternator controllers. I'm not seeing how a properly engineered B2B from the likes of Victron would be any different.
This is why you need 2 stages of protection. The first stage is that the charge source is designed not to overcharge the battery. The second and independant stage is that if the first stage fails, the BMS disconnects the battery. What is to be avoided IMO is to use the second stage routinely as a means of controlling the charging.
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38 minutes ago, Jen-in-Wellies said:
No one has mentioned it yet, so I will. An intermediate approach between alternator control and resistive wire approach to alternator connection is to use a battery to battery charger. The alternator charges the starter lead acid batt, then one, or more B2B charger charges the Lithium bank. The Lithiums get a proper charging algorithm and shut off when full. The lead acid is charged as normal and doesn't spike the alternator diodes by shutting off. It is half way between in terms of cost and engineering elegance, but still safe and more tolerant to faults than the long wire method. A good thread to read on this and the other various alternator control methods is this one:
Yes however there are two undesirables - one being that modern boats generally have 2 alternators (although this issue can be overcome by rewiring) and the B2B is both very expensive and very inefficient, turning a lot of generated power into heat.
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1 hour ago, blackrose said:
However, I don't really understand how you can have 2 different battery types both being charged by the same system. Are the lithium and LA batteries both for domestic use?
It is because of the similarities, and also the differences, between the two battery chemistries. Under discharge, the Li battery voltage remains above 13v until it is nearly flat, and so discharge current comes only from the Li, not from the LA which would have to be pulled down below 12.7v to get significant discharge.
On recharge, a voltage of 14.4v will fully charge both an LA battery and a Li battery - although from the previous para you can see that it is unlikely that the LA will need significant recharging.
All well and good so far, but the devil being in the detail... the Li battery sits at around 13.6v or less during charge, until it is very close to full. To correctly charge a Li battery, the voltage will be above 14v only for a few minutes. Li batteries do not like being held up at 14.4v or whatever, for extended periods. Whereas if the LA has in fact been discharged (due to nearly depleting the Li such that the voltage falls below 12.7v) then it needs to be held up at 14.4v for several hours to properly recharge. It is here that there is the conflict between the needs of the LA vs the needs of the Li.
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9 hours ago, Alan de Enfield said:
A new boat is built to the RCR / RCD and has the electrical propulsion system installed in accordance with the requirements (lets assume that it doesn't have the bodge of having an LA battery or a long resistance wire in the system)
The insurers (Matty has previously commented) require that batteries are installed by 'professional installers' but you suggest that the BSS will allow 'DIY home brewed systems' to be added into the system ?
My point was that the BSS has a history of applying different standards from those required by the relevant ISO. A simple example being that the ISO allows soldered lpg gas connections such as you would find in a house, whereas the BSS does not. So a boat built in full compliance with the RCD/RCR can still be a "fail" for the BSS. Similarly, things that are allowed by the BSS are contrary to the ISOs applicable to the RCD/RCR. So in answer to your final question, who knows?!
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47 minutes ago, Alan de Enfield said:
It would be very 'odd' for the BSS to have different standards to those required by Law.
It might be very "odd" but it is the case for a number of BSS standards.
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28 minutes ago, David Mack said:
Do the US bodies or BSS have a view on how you can protect the alternator if they ban you from having a LA battery permanently connected to it?
The problem arises when one uses an alternator designed for charging lead acid, to charge lithium. Not using a device for its intended purpose is always likely to be problematic! The answer is to use an alternator designed for charging lithium. Simple! And that would include having communication between the BMS and the alternator such that the latter would know if the former were about to isolate itself.
Another, or possibly additional, method is to have a load dump absorber. Sterling sell one, although they are a bit scant on the detail of what size of alternator it would cope with, and just how high a transient would be produce from a full output load dump.
I made one out of a bunch of high power Tranzorbs, it was not expensive although I have never actually put it to the test! Mostly for peace of mind just in case the bistable relay I use as the battery isolator/protector, ever goes open circuit on its own.
10 minutes ago, Tony Brooks said:I doubt it, but it would not be too difficult to simply shut the alternator down by isolating the rotor currant on most alternators. That would not cause the voltage surge mentioned above, and I think @nicknorman and possibly others here have made their own alternator controller.
Yes so for instance one could use a BMV712 battery monitor, which has a built in configurable relay, to shut down the alternator field current when some specified SoC (80, 90, 100% or whatever is configured) was reached. It would need an intermediary relay due to the current involved. Quite doable I think, but people seem a bit scared of opening up their alternators to intercept the field current.
14 minutes ago, dmr said:I don't have Lithium but am doing my research and electrical upgrades heading in that direction.
I also really do not like the (popular) idea of relying on the emergency disconnect in the BMS to give day to day charging control, and I also don't like the idea of using a parallel lead acid as a surge suppresor (and a long cable as a current limiter).
There is a new alternator controller that appears to solve all the problems by correct engineering. This is the Arco Zeus.
Downsides are its quite expensive (but then so are destroyed lithiums) and is very very new so not proven in the field, and a little effort to install including alternator modifications. I also think that ideally one should choose a lithium battery that is compatible with CANbus though these are still quite rare.
Its a shame because there are a number of alternator controller chips around - every modern car uses one - that are adjustable via some sort of computer interface. The chips can be had for a few £. All the hard work is done for you. You just need to send it the right data in terms of regulated voltage and field current limit plus optionally a few more subtleties like field current ramp rates. Not difficult for some small electronics company to take on. I guess the market is just too small to make it worthwhile.
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4 hours ago, Roberto Conigliaro said:
Hi everyone, as my AGM batteries, after many years of use, are not holding the charge anymore, I am keen on replacing them with Lithium batteries, at the moment I have 3 x AGM 230ah Xplorer batteries in parallel, charged either by the alternator or a solar power system (6 x 150w), a Victron inverter, which is used some time in the evening to charge the laptop and have extra lighting, not big appliances apart from a 12v fridge which in only switched on in the summer days.
I have some doubts and I wonder if anybody could please help with that.
- I was reading that Lithium batteries even at lower capacity they offer more power compared to a AGM, is that correct? If so, I was planning to get 3 x Sterling Power 120ah Lithium batteries https://sterling-power.com/products/lithium-batteries?variant=50407892309
or shall I better get 1 x Victron Energy LiFePO4 Battery 12,8V 330Ah Smart https://www.visionmarine.co.uk/catalog/product/view/id/112065/s/victron-energy-lifepo4-battery-12-8v-330ah-smart-bat512132410-bat512132410/category/738/
what are the pro and cons in your opinion?
- Can I charge / connect the lithium batteries same as I have the AGM ones connected at the moment? or do I need a different charging system or wiring?
any other general advice would be greatly appreciated, to follow some photos of what my system currently looks like.
Cheers!
Li batteries are fantastic. However, there are a lot of pitfalls and it is not easy to put together an effective system.
Why fantastic? Well they are just like a big bucket of electricity. You can pour energy in as fast as the tap will run. You can discharge it way down to nearly 0% and still the voltage stays up around 13v. No need to fully charge between uses.
It is worth bearing in mind that Ah is not a unit of energy, because for that you need to mulitply by the voltage. So 100Ah of lead acid (LA), where the discharge voltage is 12 to 12.6, is worth less energy than 100Ah of Lithium (Li) where the discharge voltage is 13 - 13.3v. So more energy for the same Ah.
And that is before you remember that you shouldn't really discharge your LA below 50% Soc, whereas you can discharge the Li to 10% or lower quite happily. So 100Ah of Li is worth about 200Ah of LA.
That is the good news. The bad news is that, being a big bucket of electricity, a Li battery will hoover up 100% of the maximum output from an alternator until it is nearly full. Alternators fitted to boats are generally not rated for continuous operation at maximum output, and so they will fry themselves in fairly short order. There needs to be some means to limit the maximum alternator output, to protect the alternator.
Other things with Li:
They hate being overcharged or even held at charging voltage once they are full. The mantra is "charge to full, then STOP CHARGING". Full is defined as charge current reduced to 5% of capacity. This can be easier said than done because many charge sources don't recognise when the battery is full.
They (hopefully) have a built in battery management system (BMS) that is there to protect the cells by disconnecting the battery if a cell voltage gets too high or too low or too cold. However if the BMS decides to disconnect the battery when it is being charged by an alternator, a massive voltage spike will ensue which can damage the alternator and other equipment connected to the electrical system.
So IMO one should avoid triggering the "battery emergency disconnect" algorithm in the BMS. ie set a charge voltage that is somewhat lower than the BMS cutoff voltage. The BMS protection should be considered "last resort" not "day to day control".
For the solar, you can set a fairly low charge voltage around 14.1v or so (which will still get the battery nearly full) and a float voltage much lower, say 13.3v so that no more current flows into the battery. The absorption time (time between reaching the charging voltage, and going to float) should be very short, maybe 10 minutes.
It is a bit problematic in summer if the boat is not being used - every day the batteries are pushed up to their charged voltage, without anything being taken out. This is not very good for them. So not much of an issue if you are aboard permanently, but if you leave the boat unattended with no loads on, disconnect the solar panels.
1 minute ago, Roberto Conigliaro said:Hi Gumpy, that's a nice positive piece of information and the battery cost within my budget. Could you explain more in depth what have you done to protect the alternator? looking at the equipment I have at the moment, would you have any idea of what should be done to switch to Lithium? cheers!
He and I both have the Fogstar in a caravan! But the Fogstar is good for a caravan because it has the built in heating element. If you try to charge the battery at too low a temperature, the charge is diverted to heating elements until the battery is warm enough. However on a boat, where the canal water is a great temperature stabiliser, low battery temperature is unlikely to be much of an issue especially as you can site the Li battery within the cabin where it is hopefully warm!
Otherwise, the Fogstar seems well put together but it does have quite a conservative BMS so it would be inportant to make sure the charge voltage doesn't trigger the BMS shutoff.
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1 hour ago, Tasemu said:
Weak AC is currently enabled, it could be the waveform... Do you think it unlikely that its the BMS causing an issue?
I suppose it could be. Do you have an LA in parallel? If not then a HVD is obviously going to remove any sort of battery connection to the Combi. I don’t have a Victron, but I know my Mastervolt is a bit funny if I remove the DC power with shore power connected, sometimes it carries on working, sometimes not.
Anyway it will certainly be a good idea to have the HVD set higher than the Combi charge voltage.
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2 hours ago, Tasemu said:
I was under the impression that the charger would charge my lifepo4 battery to full and then passthrough the generator power to my loads until I turn the generator off. I'm seeing a weird thing happen where when the battery reaches full, it seems to revert back to inverting, then after a few seconds when the voltage has dropped it cycles back into charging again, this cycle seems to continue. Could this be because of my victron settings? I have a gut feeling it might be.
If the Combi is switching to inverter mode, it is likely to be because the Combi doesn’t like the incoming mains. Possibly when the generator is unloaded by the charge finishing, the regulation is a bit lax and the voltage gets too high, or the waveform is a bit nasty. Pretty sure there is a setting or two to make the Victron more tolerant of ugly waveforms and to widen the acceptable voltage range.
“Weak AC” is the setting to try, and it looks like you can increase the maximum input voltage.
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8 minutes ago, Motters79 said:
So today I had a bright idea and put some diesel in a small jar which I then submerged the pumps pick up port into whilst operating the lever and it sucked up nothing. So I am concluding from this that the pump is the point of failure.
I'm now considering whether it might be better rather than replace the mechanical pump (it'll be a pig to get off and same fitting new one) to just fit an electric pump in its place? If I did that does anyone know what it's flow rate would need be or if it is indeed that crucial?
Beta says max fuel flow for the 43 is 10 litres/hr. This is "not a lot" so I would imagine that any electric diesel pump would do.
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Sorry I am talking about the summer daily rate, I don't know anything about the winter mooring rates. But a prime city centre long-ish term mooring is never going to be cheap! Yes I had a look and see that for winter moorings there is a £7 daily electricity fee. That is about 25 kwh worth. If you have "free" electricity you would be a bit stupid not to use it. 25kwh is one 1 kw heater on all the time plus a bit extra for lights etc. Put in 2kw of heating and you are well in.
You could at a pinch use about 3.5kw 24/7 and that would cost around £24. So £7 is not unreasonable.
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The daily charge is not just about the electricity, there is also water on each pontoon and rubbish collection and maintenance of the facilities. It is effectively a city centre marina and in that context, not expensive.
And I’m sure there is an element of pricing it to avoid the likelihood over-use by a few.
Lithium Batteries installation
in Boat Equipment
Posted
I did. There is a sounder on the BMS board that makes a fairly piercing shriek! BMS board is in the "engine room" area, ie close to the engine panel etc so it should be reasonably audible when driving the boat. As disconnect approaches, it starts to beep with increasingly long beeps until finally it sounds continuously for a few seconds and then disconnects. In the mean time of course it has sent an "imminent disconnect" message to the alternator controller which, if the engine is running, goes to a zero current voltage.